Method for restoring mercury-polluted soil by using oilseed rape and nano sulfur while producing

Abstract

The invention relates to the technical field of environmental protection, and discloses a method for restoring mercury-polluted soil by using oilseed rape and nano sulfur while producing. Compared with a traditional remediation method, the method has the advantages that the nano-particles of the nutrient element sulfur necessary for plants are introduced, rape crops with high stress resistance and wide adaptability are selected for matching, and the simple and efficient method for remediation while production of the rape-nano-sulfur for soil mercury pollution, which is easy to popularize in a large area, is created. The nanometer sulfur particles with a certain concentration are applied to the mercury-polluted soil, so that the accumulation of mercury on the overground part of the rape can be obviously reduced. The remediation method can be applied to the technical field of environmental protection, is particularly applied to plant remediation of light and medium mercury contaminated soil in the middle and lower reaches of the Yangtze River, and is easy and convenient to operate and wide in application range.

Description

Technical Field

[0001] This invention relates to the field of environmental protection technology, and to a method for simultaneously producing and remediating mercury-contaminated soil using rapeseed and nano-sulfur. Background Technology

[0002] Hg is one of the most toxic heavy metal elements, with strong neurotoxicity and teratogenicity. Its cumulative effect and genotoxicity are significant, and it has been listed as one of the priority pollutants for control by the World Health Organization.

[0003] Given the significant challenges in remediating large-scale heavy metal pollution in farmland, and the lack of mature technologies both domestically and internationally, coupled with the need to ensure both crop yields and agricultural product safety, the development of technologies that are acceptable to farmers and easily implemented on a large scale is urgently needed. In-situ control technology for heavy metal pollution in soil (passivation and barrier) involves applying soil conditioners to contaminated soil, causing heavy metals to be adsorbed, chelated, or precipitated, thereby altering their state in the soil, reducing their mobility and bioavailability, and decreasing the accumulation of heavy metals in crops. This reduces the harm and potential health risks posed by heavy metals to crops and is currently one of the most effective and important methods for remediating heavy metal pollution in soil. It has advantages such as simple operation and no impact on crop production, and is also a current research hotspot worldwide.

[0004] Rapeseed is a major oilseed crop widely cultivated throughout my country, with the largest planting area and total output in the world. Its greatest advantage lies in its wide adaptability to production and its edible and ornamental value. While there are reports on using rapeseed in conjunction with control agents to remediate heavy metal-contaminated soil, these agents are relatively expensive, leading to high costs for large-scale application in mercury-contaminated farmland, and some agents pose a risk of secondary pollution. Nanoparticles, due to their large specific surface area and strong catalytic and adsorption capabilities, exhibit excellent remediation effects on heavy metal-contaminated water and soil. Nanomaterials containing essential macronutrients for plants have broad research and application prospects in increasing crop yields and reducing environmental pollution. The method disclosed in this application, which utilizes rapeseed and nano-sulfur particles to simultaneously remediate mercury-contaminated soil, will provide theoretical support for further research and utilization of SNPs in the field of heavy metal pollution remediation. Summary of the Invention

[0005] In view of this, the present invention provides a method for simultaneously producing and remediating mercury-contaminated soil using novel environmentally friendly sodium-sulfur nanoparticles and specialty rapeseed varieties. This method is highly applicable and simple to implement.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for simultaneously producing and remediating mercury-contaminated soil using rapeseed and nano-sulfur includes the following steps: 1) Potting soil preparation: Fill pots with lightly to moderately Hg-contaminated soil, 1.2 kg per pot.

[0007] 2) Preparation for adding SNPs: SNPs are mixed evenly into the soil in powder form, with a concentration of 100-300 mg / kg.

[0008] 3) Seedling raising: Sow rapeseed seeds in 120-cell trays filled with vermiculite and water regularly.

[0009] 4) Transplanting: After 20 days of seedling cultivation, transplant them into the pots mentioned above, placing a leak-proof tray at the bottom of the pot; 5) Management: All seedling raising and plant cultivation experiments were conducted in climate chambers, and for daily maintenance and watering, an equal amount of water was added to the tray; 6) Harvesting: Harvest the whole plant in May when the rapeseed matures.

[0010] As a further limitation and supplement to the above technical solution, in step 1), the soil is medium-low Hg contaminated soil with an Hg concentration not exceeding 120 mg / kg.

[0011] As a further limitation and supplement to the above technical solution, in step 2), the SNPs have a particle size of 30-50 nm, a purity of >95%, and a concentration of 100-300 mg / kg.

[0012] As a further limitation and supplement to the above technical solution, in step 3), the rapeseed variety is "Qinyou 10".

[0013] As a further limitation and supplement to the above technical solution, in step 4), the seedlings are 20-25 days old and 10-15 cm tall.

[0014] As a further limitation and supplement to the above technical solution, in step 5), the temperature of the climate chamber is 22 ℃ / 20 ℃, the light cycle is 16 h / 8 h, and the light intensity is 42000 lux.

[0015] As a further definition and supplement to the above technical solution, in step 6), the whole plant refers to the entire root system and above-ground parts being harvested.

[0016] Compared with existing technologies, this invention discloses a method for simultaneously producing and remediating mercury-contaminated soil using rapeseed and nano-sulfur, which has the following beneficial effects: 1) High operability: Rapeseed has a wide planting area and strong adaptability, making it easy to promote and apply on a large scale, and thus highly operable; 2) High efficiency: SNPs significantly reduced the Hg content in stems and leaves by 49.22%-51.59% at different addition concentrations, and 200-300 mg / kg SNPs reduced the Hg content in rapeseed kernels by 13.93% and 15.23% respectively, significantly reducing the Hg content in the edible parts of rapeseed. 3) High safety: Sulfur is an essential nutrient element for plants, and there is no safety risk in using sulfur nanoparticles to assist rapeseed in remediation, thus ensuring the safety of this method. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0018] Figure 1 The effects of different SNP concentrations on aboveground and root biomass of rapeseed.

[0019] Figure 2 The effects of different SNP concentrations on Hg content in the aboveground parts and roots of rapeseed. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] This invention provides a method for simultaneously producing and remediating mercury-contaminated soil using rapeseed and nano-sulfur, which is of great significance for the effective treatment of mercury-contaminated farmland soil in my country.

[0022] To better understand the present invention, the following embodiments are provided for further detailed description of the present invention, but they should not be construed as limiting the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above-described invention are also considered to fall within the protection scope of the present invention.

[0023] The technical solution of the present invention will be further described below with reference to specific embodiments. Example

[0024] This example uses a pot experiment on Hg-contaminated soil as a case study. The Hg concentration in the soil was 120 mg / kg. The specific method is as follows: 1) Seedling raising: In October 2022, the seedling raising was carried out in the greenhouse of Nanjing Zhongshan Botanical Garden, Jiangsu Province (31°14′~32°37′N, 118°22′~119°140′E). Rapeseed seeds were sown in 120-cell trays filled with vermiculite and watered regularly. 2) Soil preparation: Air-dry the garden soil (top 20 cm) collected from Nanjing Zhongshan Botanical Garden, add 1.2 kg of air-dried soil to each flower pot (20 cm in diameter and 20 cm in depth), and place a 6 cm deep tray at the bottom of each flower pot.

[0025] 3) Preparation for Hg and SNPs addition: Hg was applied to the soil by dissolving HgCl2 in distilled water. SNPs were uniformly mixed into the soil in powder form. Five treatments were set up: 120 mg / kg Hg, 120 mg / kg Hg + 100 mg / kg SNPs, 120 mg / kg Hg + 200 mg / kg SNPs, 120 mg / kg Hg + 300 mg / kg SNPs, and a control group (CK) without Hg and S. The amount of distilled water added was the same in all treatments, and the control group was given an equal amount of distilled water.

[0026] 4) Transplanting: After 20 days of seedling cultivation, transplant the seedlings into the prepared flower pots, with 4 seedlings per pot. After 5 days, thin the seedlings to 3 seedlings per pot.

[0027] 5) Management: For daily maintenance and watering, add an equal amount of water to the tray; 6) Harvest: In May 2023, after the rapeseed matured, the biomass and Hg content of various parts of the rapeseed were measured.

[0028] This invention uses an example of Hg-contaminated soil remediation as a demonstration; specific experimental results can be found in the appendix to the specification. Figure 1 ~Attached Figure 2 .

[0029] Figure 1 The results of the effects of different SNP concentrations on the aboveground and root biomass of rapeseed showed that the addition of SNPs to Hg-contaminated soil increased the fresh weight of rapeseed seeds and the dry weight of leaves, stems and roots by 4.93%-15.49%, 18.71%-23.13%, 15.42%-35.49% and 14.62%-76.92%, respectively.

[0030] Figure 2The results of the study on the effects of different SNP concentrations on Hg content in the aboveground parts and roots of rapeseed showed that, compared with the control Hg-contaminated soil without SNPs, SNPs at different concentrations significantly reduced the Hg content in the stems and leaves by 49.22%-51.59%, and 200-300 mg / kg SNPs reduced the Hg content in rapeseed seeds by 13.93% and 15.23%, respectively, significantly reducing the Hg content in the edible parts of rapeseed.

[0031] In summary, this invention provides a method for simultaneously producing and remediating mercury-contaminated soil using rapeseed and nano-sulfur, offering technology and methods for the remediation of Hg-contaminated soil in my country.

[0032] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for simultaneously producing and remediating mercury-contaminated soil using rapeseed and nano-sulfur, characterized in that, Includes the following steps: 1) Potting soil preparation: Fill pots with soil that is slightly to moderately contaminated with mercury (Hg), 1.2 kg per pot; 2) Preparation for adding nano sulfur (SNPs): SNPs are uniformly mixed into the soil in powder form, with a concentration of 100-300 mg / kg; 3) Seedling raising: Sow rapeseed seeds in 120-cell trays filled with vermiculite and water regularly; 4) Transplanting: After 20 days of seedling cultivation, transplant them into the pots mentioned above, placing a leak-proof tray at the bottom of the pot; 5) Management: All seedling raising and plant cultivation experiments were conducted in climate chambers, and for daily maintenance and watering, an equal amount of water was added to the tray; 6) Harvesting: Harvest the whole plant in May when the rapeseed matures.

2. The method for simultaneously producing and remediating mercury-contaminated soil using rapeseed and nano-sulfur according to claim 1, characterized in that, In step 1), the soil is medium-low Hg contaminated soil with an Hg concentration not exceeding 120 mg / kg.

3. The method for simultaneously producing and remediating mercury-contaminated soil using rapeseed and nano-sulfur according to claim 1, characterized in that, In step 2), the SNPs have a particle size of 30-50 nm, a purity of >95%, and a concentration of 100-300 mg / kg.

4. The method for simultaneously producing and remediating mercury-contaminated soil using rapeseed and nano-sulfur according to claim 1, characterized in that, In step 3), the rapeseed variety is "Qinyou 10".

5. The method for simultaneously producing and remediating mercury-contaminated soil using rapeseed and nano-sulfur according to claim 1 or 4, characterized in that, In step 4), the seedlings are 20-25 days old and 10-15 cm tall.

6. The method for simultaneously producing and remediating mercury-contaminated soil using rapeseed and nano-sulfur according to claim 1, characterized in that, In step 5), the temperature of the climate chamber is 22 ℃ / 20 ℃, the light cycle is 16 h / 8 h, and the light intensity is 42000 lux.

7. The method for simultaneously producing and remediating mercury-contaminated soil using rapeseed and nano-sulfur according to claim 1, characterized in that, In step 6), the whole plant refers to the entire root system and above-ground parts that are harvested.

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