Application of the herb Rumex in remediation of radioactive radium contaminated soil

Abstract

The present invention provides an application of the herb Rumex in remediating radioactive radium contaminated soil, wherein the herb Rumex is planted in 226 Ra contaminated soil, and carried out cultivation management, when it grew to maturity, retain the roots, and harvest the aboveground parts multiple times to reduce 226 Ra in contaminated soil 226 Ra content until it reaches the environmental safety standard. The present invention uses Rumex to repair acidic radioactive radium contaminated soil and finds that the plant has 226 Ra has a high transfer coefficient and enrichment coefficient, among which the transfer coefficient is greater than 2, the enrichment coefficient is 0.4-0.6, and the contribution rate of aboveground part to the removal of Ra is more than 70%. 226 Extraction of Ra from contaminated soil 226 Ra, and has the ability to make the roots radioactive 226 Ra is transferred to the aboveground part of the soil. Furthermore, Rumex is suitable for various growing environments, has a large biomass, can be sown once and harvested multiple times over many years, and requires relatively extensive management during its growth process, making it suitable for remediation of large areas of soil contaminated with medium to low levels of acidic radium.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental pollution control, and in particular to application of a herbaceous plant, Rumex, in repairing radioactive radium-contaminated soil. Background Art

[0002] Ra is a product of the natural decay chain of U and Th. Industrial and agricultural activities such as uranium mining, phosphate fertilizer production and use generate three wastes and thus contaminate the soil. 226 Ra and other pollutants lead to increased environmental radiation levels, radon release and other problems, polluting the environment and threatening human health. 226 The average activity concentration of Ra does not exceed 0.18 Bq / g after deducting the local background value, and it can be opened or used without restriction (GB 23727-2020).

[0003] Compared to traditional physical and chemical methods, phytoremediation is considered a large-scale, low-cost, green technology for remediating contaminated soil. Screening for plants with high biomass and a specific ability to accumulate target elements for use in metal-contaminated soil remediation represents a new trend, direction, and approach in phytoremediation. Currently, phytoremediation research has focused more on soils contaminated with uranium and cesium, but research on soils contaminated with radium is limited.

[0004] Therefore, it is necessary to develop a method to use plants to remediate radioactive Ra contaminated soil. Summary of the Invention

[0005] To address the aforementioned issues in the existing technology, the present invention provides the use of the herb Rumex rapa for the remediation of radioactive radium-contaminated soil. Rumex rapa has low planting costs, rapid growth, high biomass yield, strong stress resistance, and robust regeneration capacity. It possesses strong radium accumulation and transfer capabilities for the remediation of radioactive radium-contaminated soil.

[0006] The specific content of the invention is as follows:

[0007] The present invention provides an application of the herb Rumex in remediating radioactive radium contaminated soil. The radioactive radium contaminated soil is 226 The activity of Ra is 200-5000Bg / kg 226 Ra contaminated soil, the applications include:

[0008] exist 226 Sowing Rumex seeds in Ra-contaminated soil and carrying out cultivation management, retaining the roots of the Rumex after growing to maturity, harvesting the aboveground parts of the Rumex multiple times, or harvesting the entire Rumex plant and then planting it again, so as to reduce 226 Ra in contaminated soil 226 Ra content, up to226 Ra in contaminated soil 226 Ra content meets environmental safety standards;

[0009] The aboveground part of Rumex 226 The enrichment factor of Ra is 0.4-0.6;

[0010] The Rumex 226 The transfer coefficient of Ra is greater than 2.

[0011] Optionally, the aboveground part of Rumex 226 The enrichment activity of Ra reaches 330.6Bq / kg.

[0012] Optionally, the root of Rumex 226 The enrichment activity concentration of Ra reaches 117Bq / kg.

[0013] Optionally, the 226 Ra contaminated soil is weakly acidic contaminated soil.

[0014] Optionally, the 226 The pH value of Ra-contaminated soil is 5-6.

[0015] Optionally, the sowing amount of the Rumex seeds is 0.2-0.5 kg / mu.

[0016] Optionally, the cultivation management includes: 226 Ra contaminated soil is leveled, fined, watered and fertilized.

[0017] Optionally, the fertilization construction refers to 226 Before planting the Rumex on Ra-contaminated soil, base fertilizer was applied, and topdressing fertilizer was applied during the growth of the Rumex.

[0018] Optionally, the base fertilizer and topdressing fertilizer are both nitrogen, phosphorus and potassium compound fertilizers.

[0019] Optionally, the watering construction is carried out according to the 226 Ra contaminated soil water shortage situation, so that the 226 The moisture content of Ra-contaminated soil was maintained at 40%-70% of the field capacity.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] The present invention provides an application of Rumex in remediating radioactive radium contaminated soil, by planting Rumex in 226 Ra contaminated soil, and carried out cultivation management, when Rumex grows to maturity, retain the roots of Rumex, harvest the aboveground part for multiple crops, or harvest the whole Rumex and plant it again until226 Ra in contaminated soil 226 The Ra content reaches the environmental safety standard. The present invention uses Rumex to repair acidic radioactive radium contaminated soil (200-5000Bq / kg soil) and finds that Rumex has a 226 Ra has a high transfer coefficient and enrichment coefficient, among which Rumex has a high 226 The transfer coefficient of Ra is greater than 2, and the aboveground enrichment coefficient can reach 0.4-0.6; the aboveground part of Rumex contributes more than 70% to the removal of Ra, proving that it can be used from a lower 226 Extraction of Ra from contaminated soil 226 Ra, and has the ability to make the roots radioactive 226 Ra transfers to the aboveground part of the soil. Furthermore, Rumex is suitable for various growing environments, has a large biomass, and can be harvested multiple times over many years after sowing once. Its relatively extensive growth management process does not damage the basic structure and properties of the soil. It is suitable for remediating large areas of soil contaminated with medium to low levels of acidic radium, providing a new approach for the remediation of radioactive radium-contaminated soil. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means a limitation on the present invention and its application or use. Based on the embodiments of the present invention, any product that is identical or similar to the present invention obtained by anyone under the guidance of the present invention or by combining the features of the present invention with other prior arts falls within the scope of protection of the present invention. In addition, all other embodiments obtained by ordinary technicians in this field without carrying out creative work fall within the scope of protection of the present invention.

[0023] If no specific experimental steps or conditions are specified in the examples, the experiments can be carried out according to the conventional experimental steps or conditions described in the prior art. The reagents and other instruments used, if the manufacturers are not specified, are all commercially available conventional reagents.

[0024] Technologies, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies, methods, and equipment should be considered part of the description of the present invention.

[0025] In the description of the present invention, it should be understood that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0026] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0027] Rumex, also known as Rumex K-1 hybrid sorrel (Rumex patientia × Rumex tianschanicus cv. Rumex), is a perennial herbaceous plant in the Polygonaceae family. It is a high-yielding herb with a lifespan of up to 25 years, with a peak productive period of 10-15 years. Under good water and fertilizer conditions, it can be harvested every 30-45 days, yielding 150-225 tons of fresh grass per hectare and 15-22.5 tons of hay per hectare. Rumex is renewable, with a single planting providing continuous use for 10 to 15 years, yielding up to 10,000 kilograms of fresh leaves per mu. Rumex is characterized by high yield, rapid growth, and excellent quality. It is also tolerant to cold, drought, waterlogging, alkali, and barrenness, has a wide adaptability, and possesses strong adversity-resistant and regenerative abilities.

[0028] The present invention is based on the fact that Rumex used to repair radioactive radium contaminated soil is a perennial herbaceous plant of the genus Rumex in the Polygonaceae family. It has high yield, a lifespan of up to 25 years, and a high-yield period of up to 10-15 years. Under good water and fertilizer conditions, it can be harvested once every 30-45 days, with a fresh grass yield of up to 150-225 tons / hectare and a dry grass yield of up to 15-22.5 tons / hectare. It is renewable and can be used continuously for 10 to 15 years after planting once, with a yield of up to 10,000 kilograms of fresh leaves per mu. Rumex has the characteristics of high yield, fast growth and excellent quality, as well as cold resistance, drought resistance, waterlogging resistance, alkali resistance, barrenness resistance, wide adaptability, and strong resistance to adverse regeneration. The present invention applies it to the repair of radioactive radium contaminated soil and achieves good repair effects. Specific applications are as follows:

[0029] The present invention provides an application of the herb Rumex in remediating radioactive radium contaminated soil. The radioactive radium contaminated soil is 226 The activity concentration of Ra is 200-5000Bg / kg 226 Ra contaminates soil, specifically including:

[0030] exist 226 Sow Rumex seeds in Ra-contaminated soil and carry out cultivation management. After growing to maturity, retain the roots of Rumex and harvest the aboveground parts of Rumex multiple times or replant them to reduce 226 Ra in contaminated soil 226 Ra content, up to 226 Ra in contaminated soil 226 The Ra content meets environmental safety standards.

[0031] In practice, the roots of growing Rumex can absorb radioactive radium from radioactive radium contaminated soil and transfer it to the aboveground parts of Rumex. The transfer coefficient is more than 2. Given that Rumex has the advantage of being planted once and harvested continuously for 10 to 15 years, the aboveground parts of Rumex can be harvested repeatedly to achieve the goal of contaminating the contaminated soil. 226 The transfer and enrichment of Ra until the radioactive radium content in the soil reaches environmental safety standards. The present invention also allows for the removal of the entire Rumex plant from the contaminated soil, followed by the planting and management of a new batch of Rumex plants. The specific method depends on the growth of the Rumex plants.

[0032] In the specific implementation, the seeds of Rumex of the embodiment of the present invention were sown in late September at 0.2-0.5 kg / mu. 226 In radioactive radium contaminated soil with Ra activity of 564.2-845.9Bq / kg, after sowing and growing for 3 months, the height of Rumex seedlings exceeds 20cm, and the aboveground part of Rumex is harvested, and the roots are retained. The roots retained after the first harvest have not yet grown thick, and they are dormant in winter until the spring of the following year. On-site management such as fertilization and watering are strengthened, and Rumex seedlings emerge and grow luxuriantly. The second harvest is carried out in early July in summer, and the remaining rhizomes are thick. The aboveground part weighs more than 4-7 tons per hectare, which is much higher than the yield of many enriched plants. In addition, according to the aboveground part and roots of Rumex, 226 The enrichment test of Ra found that the aboveground part of Rumex 226 The concentration of Ra in the aboveground part of Rumex is nearly 3 times that in the root. 226 The enrichment activity concentration of Ra can reach 330.6Bq / kg. 226 The enrichment concentration of Ra can reach 117Bq / kg; the aboveground part of Rumex 226 The enrichment coefficient of Ra can reach 0.4-0.6.

[0033] In some embodiments, Rumex has a wide range of land adaptability. This example illustrates that Rumex can be applied to weakly acidic soils. 226 Ra contaminated soil; 226 The pH value of Ra-contaminated soil is 5-6.

[0034] In some embodiments, the seeding is completed 226Cultivation and management of Ra-contaminated soil can promote the growth of Rumex, increase the biomass of Rumex, and thus improve the extraction rate of radioactive radium in the contaminated soil. Cultivation management includes soil leveling, watering, and fertilizing. Among them: during the cultivation of Rumex, watering is performed according to the water shortage of the soil to keep the soil moisture content at 40%-70% of the field water holding capacity. The above-mentioned fertilization refers to the application of base fertilizer before planting Rumex in radioactive radium-contaminated soil, and the application of topdressing during the growth of Rumex. The above-mentioned base fertilizer and topdressing are both conventional N, P, and K compound fertilizers. Use local nitrogen, phosphorus, and potassium compound fertilizers, and apply base fertilizer and topdressing in appropriate amounts according to the local soil quality.

[0035] In order to enable those skilled in the art to more clearly understand the present invention, the application of the herb Rumex of the present invention in remediating radioactive radium contaminated soil is now described in detail through the following examples.

[0036] The following examples used Rumex seeds planted on-site in acidic soil contaminated with low-level radioactivity in decommissioned uranium mining and smelting sites in southern my country. Due to its cold tolerance, Rumex successfully cultivated and thrived in the acidic soil contaminated in Guangdong Province, demonstrating its ability to thrive in southern acidic soils and its high transfer and enrichment efficiency for radioactive Ra.

[0037] The fertilizers and pesticides in the following examples can all be purchased through conventional commercial channels.

[0038] The field trial was conducted at a decommissioned uranium mining site in southern my country. The region has a subtropical monsoon climate, with an average annual temperature of 21°C, an average annual rainfall of 1,700 mm, and approximately 310 frost-free days. The physical and chemical properties of the soil contaminated with radioactive radium are shown in Table 1. The soil at the decommissioned uranium mining site is sandy loam with an acidic pH.

[0039] Table 1 Physical and chemical properties of the tested soil

[0040]

[0041] Example 1

[0042] (1) Field test on the absorption capacity of Rumex for radium

[0043] Loosen and level the contaminated soil at the site, then apply base fertilizer. Sprinkle Rumex seeds (0.2-0.5 kg / mu) on the soil, cover it, and water it appropriately. During the Rumex growth process, apply appropriate topdressing (such as commercially available nitrogen, phosphorus, and potassium compound fertilizers), spray pesticides (such as commercially available abamyl benzoyl, emamectin benzoate, etc.), and water the plants to promote their growth, depending on the crop's growth and soil moisture conditions. Harvest the aboveground parts of the plants after three months of growth. After the first harvest, harvest the aboveground parts for a second time, and also harvest the roots during the second harvest.

[0044] The obtained plants were separated into aerial parts and roots, rinsed with tap water, and air-dried. The soil and plants were dried and crushed for subsequent analysis.

[0045] (2) Repair capability verification

[0046] 1) Rumex aboveground parts, roots and soil 226 Determination of Ra activity concentration

[0047] In the soil 226 The measurement of Ra is based on the "γ spectrum analysis method of radionuclides in soil" (GB / T11743-2013). 226 The measurement of Ra is based on the 226 Analysis method for Ra-Emission method" (GB / T 13073-2010).

[0048] Radioactivity in the aboveground parts, roots and soil of Rumex 226 The activity concentrations of Ra are 330.6, 117.0, 564.2-845.9 Bq / kg respectively.

[0049] 2) Rumex aboveground part and root 226 Determination of Ra enrichment coefficient and transfer coefficient

[0050] BCF = Bq / kg of a nuclide in a plant or plant tissue / Bq / kg of that nuclide in soil.

[0051] Transfer coefficient (TF) = activity of an element in the aboveground part of the plant / activity of the element in the root of the plant.

[0052] The results showed that the aboveground part of Rumex 226 The enrichment factor of Ra is 0.4-0.6 pairs 226 The Ra transfer coefficient is greater than 2 and can reach 2.8, which is higher than that of most plants reported in the literature.

[0053] 3) Rumex aerial parts 226 Determination of Ra removal contribution rate

[0054] According to the weight of Rumex aboveground part, root, 226 The contribution of aboveground Ra removal to total Ra removal was calculated as follows: Contribution of aboveground Ra removal by Rumex = 100% × (total Ra removal by aboveground Ra plus the total Ra removal by Rumex aboveground and roots).

[0055] Computational analysis showed that the removal of Rumex aboveground parts 226The contribution rate of Ra was more than 70%, which showed that Rumex had the plant extraction function of Ra in soil.

[0056] This example demonstrates that Rumex is not only suitable for the north, but can also grow normally in acidic contaminated soils in the south. It has a large biomass and can be harvested multiple times over many years after sowing once. It is a very promising and easy-to-operate method for remediating radium-contaminated soils.

[0057] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0058] For simplicity of description, the method embodiments are described as a series of actions. However, those skilled in the art should be aware that the present invention is not limited by the order of the actions described, as certain steps can be performed in other orders or simultaneously according to the present invention. Furthermore, those skilled in the art should also be aware that the embodiments described in this specification are preferred embodiments, and the actions and components involved are not necessarily required for the present invention.

[0059] The above is a detailed introduction to the application of the herb Rumex provided by the present invention in the remediation of radioactive radium contaminated soil. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An application of the herb Rumex in remediating radioactive radium contaminated soil, characterized in that: The application is targeted at 226 Ra activity concentration is 200-5000 Bg / kg 226 Ra contaminated soil, the applications include: exist 226 Sowing Rumex seeds in Ra-contaminated soil and carrying out cultivation management, retaining the roots of the Rumex after growing to maturity, harvesting the aboveground parts of the Rumex multiple times, or harvesting the entire Rumex plant and then planting it again, in order to reduce 226 Ra in contaminated soil 226 Ra content, up to 226 Ra in contaminated soil 226 Ra content meets environmental safety standards; The aboveground part of Rumex 226 The enrichment factor of Ra is 0.4-0.6; The Rumex 226 The transfer coefficient of Ra is greater than 2.

2. The use according to claim 1, characterized in that The aboveground part of Rumex 226 The enrichment activity concentration of Ra reached 330.6 Bq / kg.

3. The use according to claim 1, characterized in that The roots of Rumex 226 The enrichment activity concentration of Ra reaches 117 Bq / kg.

4. The use according to claim 1, characterized in that described 226 Ra contaminated soil is weakly acidic contaminated soil.

5. The use according to claim 4, characterized in that described 226 The pH value of Ra-contaminated soil is 5-6.

6. The use according to claim 1, characterized in that The sowing amount of the Rumex seeds is 0.2-0.5 kg / mu.

7. The use according to claim 1, characterized in that The cultivation management includes: 226 Ra contaminated soil is leveled, fined, watered and fertilized.

8. The use according to claim 7, characterized in that The fertilization construction refers to the 226 Before planting the Rumex on Ra-contaminated soil, base fertilizer was applied, and topdressing fertilizer was applied during the growth of the Rumex.

9. The use according to claim 8, characterized in that The base fertilizer and topdressing are both nitrogen, phosphorus and potassium compound fertilizers.

10. The use according to claim 7, characterized in that The watering construction is carried out according to the 226 Ra contaminated soil water shortage situation, so that the 226 The moisture content of Ra-contaminated soil was maintained at 40%-70% of the field capacity.

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