A material for degrading soil organic pollutants

Abstract

This application relates to a material for degrading organic pollutants in soil and its preparation method, characterized by the following steps: (1) weighing zinc salt, indium salt and sodium acetate; (2) adding the zinc salt, indium salt and sodium acetate weighed in step (1) to a mixed solvent of ethylene glycol / water, and stirring magnetically to form a uniform mixed solution; placing the uniformly mixed solution in a reaction vessel and reacting at 150-180°C in an oven for 10-15 hours; (3) centrifuging the solution obtained in step (2) after natural cooling to obtain the product, and washing it alternately with ethanol and deionized water; (4) placing the washed material in a tube furnace and calcining it at 300-400°C for 1-2 hours to obtain a zinc oxide-indium oxide composite material. The material has a stable structure, a simple preparation process, and a high degradation rate for organic pollutants in soil.

Description

Technical Field

[0001] This invention belongs to the field of soil remediation technology, specifically relating to the preparation method of zinc oxide / indium oxide porous microsphere photocatalyst and its application in degrading organic pollutants in soil. Background Technology

[0002] Soil is a core component of the ecological environment and one of the main resources upon which humankind depends for survival. It is highly sensitive to environmental changes. In recent years, soil environmental quality has deteriorated, and soil pollution has intensified. Soil pollution can be categorized into organic and inorganic pollution based on the type of pollutants. Organic pollution refers to the entry of toxic and harmful organic substances into the soil, where the quantity and rate of entry exceed the soil's purification capacity. This disrupts the natural dynamic balance, allowing the accumulation of pollutants to gradually dominate, leading to dysfunction of the soil's natural functions, a decline in soil quality, and impacts crop growth and development, as well as a decrease in yield and quality. Once organic pollution enters the soil, it can endanger crop growth and the survival of soil organisms. For example, the presence of diphenyl ether in farmland can easily cause large-scale crop death. Contact with contaminated soil poses a serious threat to the health of animals and humans.

[0003] For soil remediation technologies contaminated with organic matter, the main technologies include thermal desorption, photodegradation, soil leaching, and bioremediation. Among these, photodegradation technology, with its advantages of non-toxicity, rapid and efficient operation, good selectivity, and low energy consumption, is one of the most actively researched methods for treating volatile organic compounds. For example, Chinese patent CN111282591A discloses a Sb2S3 / AgI / Ag / BON photocatalyst for soil remediation, which utilizes a strategy of constructing a nanocomposite structure to promote the separation of photogenerated charge carriers through an accompanying electric field. By leveraging the micropotential of a metal-semiconductor / core-shell nanocomposite structure driven by electromagnetic induction to enhance charge separation in the semiconductor photocatalyst, and applying an external magnetic field to a conventional photocatalytic reactor device, the performance of photocatalytic degradation of pollutants is improved. Chinese patent CN108421821A discloses a method for degrading polycyclic aromatic hydrocarbons (PAHs) in soil using a cotton stalk biochar-based titanium dioxide photocatalyst. The method involves preparing cotton stalk biochar using cotton stalks. The biochar is added to a mixed solution of distilled water and anhydrous ethanol, ultrasonically treated for 1 hour, then titanium dioxide is added and stirred until homogeneous. The mixture is then transferred to a hydrothermal reactor, which is placed in a homogeneous reactor. The temperature of the homogeneous reactor is set at 120-210℃, and the reaction is carried out continuously for 12-24 hours. After cooling and centrifugation, the... The lower precipitate was washed with distilled water, dried, and ground to obtain cotton stalk biochar-based titanium dioxide photocatalyst. The biochar prepared from cotton stalks is loose and porous with a large specific surface area. When applied to the soil, the cotton stalk biochar-based titanium dioxide photocatalyst not only improves the soil texture, but also, due to the various groups such as phenolic hydroxyl groups, carboxyl groups, and acid anhydrides distributed on the surface of the biochar, can adsorb and fix polycyclic aromatic hydrocarbons in the soil. Moreover, coupled with the photocatalytic oxidation of titanium dioxide, polycyclic aromatic hydrocarbon molecules can be degraded into non-polluting small molecules.

[0004] However, existing photocatalytic materials for degrading organic matter still suffer from problems such as severe photogenerated electron-hole recombination, low specific surface area, complex preparation processes, structural instability, and low degradation efficiency, directly limiting their large-scale application. Therefore, the purpose of this invention is to provide a composite photocatalyst with excellent adsorption performance, stable structure, simple preparation process, and large specific surface area to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a zinc oxide / indium oxide porous microsphere and its preparation method, as well as its application in the degradation of organic pollutants in soil. This material has high degradation efficiency for organic pollutants, stable structure, large specific surface area, and is environmentally friendly, and can be used for large-scale production.

[0006] A method for preparing a material for degrading organic matter in soil, characterized by comprising the following steps:

[0007] (1) Weigh out 1-3 mmol of zinc salt, 1-3 mmol of indium salt, and 2-5 mmol of sodium acetate;

[0008] (2) Add the zinc salt, indium salt and sodium acetate weighed in step (1) to the mixed solvent of ethylene glycol / water, and stir magnetically for 5-10 min to form a uniform mixed solution; place the uniformly mixed solution in a reaction vessel and react at 150-180℃ in an oven for 10-15 h.

[0009] (3) After the solution obtained in step (2) is cooled naturally, it is centrifuged to obtain the product, and then washed with ethanol and deionized water alternately; (4) The washed material is placed in a tube furnace and calcined at 300-400 degrees Celsius for 1-2 hours to obtain a zinc oxide-indium oxide composite material.

[0010] Specifically, zinc salts are selected from zinc sulfate, zinc chloride, and zinc nitrate;

[0011] Specifically, the indium salt is selected from indium sulfate, indium chloride, and indium nitrate;

[0012] Specifically, the volume ratio of ethylene glycol to water is (20-50) ml: (10-20) ml;

[0013] Specifically, the zinc oxide-indium oxide material is formed by the self-assembly of zinc oxide-indium oxide nanosheets into porous microspheres.

[0014] Compared with the prior art, the technical effects achieved by this application are as follows:

[0015] This application prepares a zinc oxide-indium oxide composite material. Zinc oxide and indium oxide are grown to form nanosheets, which then self-assemble into a highly porous spherical structure. This porous spherical structure has a narrow, elongated pore structure, a high specific surface area, and strong adsorption properties. It can strongly adsorb organic pollutants onto the surface of the nanosheets, rapidly degrading organic pollutants in the soil under light irradiation, thereby improving the degradation efficiency of soil organic matter. Furthermore, the zinc oxide-indium oxide composite promotes the separation of photogenerated charge carriers, thereby improving light absorption efficiency and photocatalytic activity. In addition, the preparation process of this application is simple, the material structure is stable, which is conducive to large-scale production and application, and has practical significance. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0017] Appendix Figure 1 This is a scanning electron microscope image of the zinc oxide-indium oxide composite material of this application;

[0018] Appendix Figure 2 For the appendix Figure 1 A magnified view of a portion of the image. Detailed Implementation

[0019] Example 1

[0020] A method for preparing a material for degrading organic matter in soil specifically includes the following steps:

[0021] (1) Weigh out 1 mmol of zinc nitrate, 1 mmol of indium nitrate, and 2 mmol of sodium acetate;

[0022] (2) Add the zinc nitrate, indium nitrate and sodium acetate weighed in step (1) to a mixed solvent of 30 ml ethylene glycol / 10 ml water, and stir magnetically for 10 min to form a uniform mixed solution; place the uniformly mixed solution in a reaction vessel and react at 180 °C in an oven for 10 h.

[0023] (3) After the solution obtained in step (2) is cooled naturally, it is centrifuged to obtain the product, and then washed three times with ethanol and deionized water alternately.

[0024] (4) The washed material was placed in a tube furnace and calcined at 300 degrees Celsius for 1 hour to obtain a zinc oxide-indium oxide composite material.

[0025] Example 2

[0026] A method for preparing a material for degrading organic matter in soil specifically includes the following steps:

[0027] (1) Weigh out 1 mmol of zinc nitrate, 1 mmol of indium nitrate, and 2 mmol of sodium acetate;

[0028] (2) Add the zinc nitrate, indium nitrate and sodium acetate weighed in step (1) to a mixed solvent of 30 ml ethylene glycol / 10 ml water, and stir magnetically for 10 min to form a uniform mixed solution; place the uniformly mixed solution in a reaction vessel and react at 150 °C in an oven for 10 h.

[0029] (3) After the solution obtained in step (2) is cooled naturally, it is centrifuged to obtain the product, and then washed three times with ethanol and deionized water alternately.

[0030] (4) The washed material was placed in a tube furnace and calcined at 300 degrees Celsius for 1 hour to obtain a zinc oxide-indium oxide composite material.

[0031] Example 3

[0032] A method for preparing a material for degrading organic matter in soil, characterized by comprising the following steps:

[0033] (1) Weigh out 2 mmol of zinc nitrate, 2 mmol of indium nitrate, and 3 mmol of sodium acetate;

[0034] (2) Add the zinc nitrate, indium nitrate and sodium acetate weighed in step (1) to a mixed solvent of 30 ml ethylene glycol / 20 ml water, and stir magnetically for 10 min to form a uniform mixed solution; place the uniformly mixed solution in a reaction vessel and react at 150 °C in an oven for 10 h.

[0035] (3) After the solution obtained in step (2) is cooled naturally, it is centrifuged to obtain the product, and then washed three times with ethanol and deionized water alternately.

[0036] (4) The washed material was placed in a tube furnace and calcined at 300 degrees Celsius for 1 hour to obtain a zinc oxide-indium oxide composite material.

[0037] Example 4

[0038] A method for preparing a material for degrading organic matter in soil, characterized by comprising the following steps:

[0039] (1) Weigh out 2 mmol of zinc nitrate, 2 mmol of indium nitrate, and 3 mmol of sodium acetate;

[0040] (2) Add the zinc nitrate, indium nitrate and sodium acetate weighed in step (1) to a mixed solvent of 20 ml ethylene glycol / 20 ml water, and stir magnetically for 10 min to form a uniform mixed solution; place the uniformly mixed solution in a reaction vessel and react at 150 °C in an oven for 10 h.

[0041] (3) After the solution obtained in step (2) is cooled naturally, it is centrifuged to obtain the product, and then washed three times with ethanol and deionized water alternately.

[0042] (4) The washed material was placed in a tube furnace and calcined at 400 degrees Celsius for 1 hour to obtain a zinc oxide-indium oxide composite material.

[0043] Comparative Example 1

[0044] A method for preparing a material for degrading organic matter in soil, characterized by comprising the following steps:

[0045] (1) Weigh out 1 mmol of zinc nitrate and 2 mmol of sodium acetate;

[0046] (2) Add the zinc nitrate and sodium acetate weighed in step (1) to a mixed solvent of 30 ml ethylene glycol / 10 ml water, and stir magnetically for 10 min to form a uniform mixed solution; place the uniformly mixed solution in a reaction vessel and react at 180 °C in an oven for 10 h.

[0047] (3) After the solution obtained in step (2) is cooled naturally, it is centrifuged to obtain the product, and washed three times with ethanol and deionized water alternately; (4) The washed material is placed in a tube furnace and calcined at 300 degrees Celsius for 1 hour to obtain zinc oxide material.

[0048] Comparative Example 2

[0049] A method for preparing a material for degrading organic matter in soil, characterized by comprising the following steps:

[0050] (1) Weigh out 1 mmol of indium nitrate and 2 mmol of sodium acetate;

[0051] (2) Add the indium nitrate and sodium acetate weighed in step (1) to a mixed solvent of 30 ml ethylene glycol / 10 ml water, and stir magnetically for 10 min to form a uniform mixed solution; place the uniformly mixed solution in a reaction vessel and react at 180 °C in an oven for 10 h.

[0052] (3) After the solution obtained in step (2) is cooled naturally, it is centrifuged to obtain the product, and then washed three times with ethanol and deionized water alternately.

[0053] (4) The washed material was placed in a tube furnace and calcined at 300 degrees Celsius for 1 hour to obtain an indium oxide composite material.

[0054] The specific surface area of ​​the materials in Example 1 and Comparative Examples 1-2 was tested, and the results are shown in Table 1.

[0055] Organic pollutant degradation test experiment:

[0056] 3 kg of contaminated soil sample with an atrazine content of 5% was weighed and divided into 6 equal portions. 30 g of the material from Examples 1-4 or Comparative Examples 1-2 was weighed and mixed thoroughly with each sample. The mixed samples were irradiated with a 20W UV lamp, and the soil was turned over again every 60 minutes. The soil remediation effect was tested after 24 hours. The same method was used to test the remediation effect of Examples 1-4 and Comparative Examples 1-2 on tetracycline-containing soil.

[0057] <![CDATA[Specific surface area m 2 / g]]> Example 1 42 Example 2 28 Example 3 35 Example 4 40 Comparative Example 1 25 Comparative Example 2 16

[0058] Atrazine removal rate Tetracycline removal rate Example 1 68％ 69％ Example 2 73％ 79％ Example 3 65％ 74％ Example 4 76％ 70％ Comparative Example 1 57％ 63％ Comparative Example 2 62％ 58％

[0059] As can be seen from the table above, the specific surface area of ​​the indium oxide / zinc oxide porous microsphere composite material is greater than that of indium oxide or zinc oxide alone, and its photodegradation efficiency is higher than that of its photocatalytic performance when used alone.

[0060] The embodiments described above are merely preferred embodiments of the present invention, but are not limited thereto. Those skilled in the art can easily understand the spirit of the present invention based on the above embodiments and make different extensions and variations, but as long as they do not depart from the spirit of the present invention, they are all within the protection scope of the present invention.

Claims

1. A method for preparing a material for degrading organic matter in soil, characterized in that, Includes the following steps: (1) Weigh out 1-3 mmol of zinc salt, 1-3 mmol of indium salt, and 2-5 mmol of sodium acetate; (2) Add the zinc salt, indium salt and sodium acetate weighed in step (1) to a mixed solvent of ethylene glycol / water, with a volume of (20-50) mL: (10-20) mL of ethylene glycol / water; stir magnetically for 5-10 min to form a uniform mixed solution; place the uniformly mixed solution in a reaction vessel and react at 150-180℃ in an oven for 10-15 h; (3) After the solution obtained in step (2) is cooled naturally, it is centrifuged to obtain the product, and then washed with ethanol and deionized water alternately. (4) Place the washed material in a tube furnace and calcine it at a constant temperature of 300-400 degrees Celsius for 1-2 hours to obtain a zinc oxide-indium oxide composite material.

2. The method for preparing a material for degrading organic matter in soil according to claim 1, wherein the zinc salt is selected from zinc sulfate, zinc chloride, and zinc nitrate.

3. The method for preparing a material for degrading organic matter in soil according to claim 1, wherein the indium salt is selected from indium sulfate, indium chloride, and indium nitrate.

4. The method for preparing a material for degrading organic matter in soil according to claim 1, wherein the zinc oxide-indium oxide material is formed by the self-assembly of zinc oxide-indium oxide nanosheets into porous microspheres.

5. A material for degrading organic matter in soil, characterized in that, It is prepared by any one of claims 1-4.

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