Material for degrading organic pollutants in soil

Abstract

The invention relates to a material for degrading organic pollutants in soil and a preparation method thereof, and the preparation method is characterized by comprising the following steps: (1) weighing zinc salt, indium salt and sodium acetate; (2) adding the zinc salt, the indium salt and the sodium acetate weighed in the step (1) into a mixed solvent of ethylene glycol / water, and magnetically stirring to form a uniformly mixed solution; putting the uniformly mixed solution into a reaction kettle, and reacting in a drying oven at 150-180 DEG C for 10-15 hours; (3) naturally cooling the solution obtained in the step (2), centrifuging to obtain a product, and alternately washing with ethanol and deionized water; and (4) placing the washed material in a tubular furnace, and calcining at a constant temperature of 300-400 DEG C for 1-2 hours to obtain the zinc oxide-indium oxide composite material which is stable in structure and simple in preparation process and has a very high degradation rate on organic pollutants in soil.

Description

Technical Field

[0001] The invention belongs to the technical field of soil remediation, and specifically relates to a preparation method of a zinc oxide / indium oxide porous microsphere photocatalyst and an application thereof in degrading organic pollutants in soil. Background Art

[0002] Soil is a core component of the ecological environment and one of the main resources for human survival. It is highly sensitive to environmental changes. In recent years, soil environmental quality has deteriorated and soil pollution has continued to intensify. According to the types of soil pollutants, it can be divided into organic pollution and inorganic pollution. Among them, soil organic pollution refers to the fact that after toxic and harmful organic substances enter the soil, their quantity and speed exceed the speed of soil purification, destroying the natural dynamic balance, and making the accumulation process of pollutants gradually dominate, thus leading to the disorder of the normal function of the soil, the decline of soil quality, and affecting the growth and development of crops, as well as the decline of yield and quality. After organic pollution enters the soil, it can endanger the growth of crops and the survival of soil organisms. For example, if diphenyl ether is contained in farmland, it is easy to cause large-scale death of crops. After animals or humans come into contact with contaminated soil, it seriously threatens their health.

[0003] For the remediation technology of organic polluted soil, it mainly includes thermal desorption technology, photodegradation technology, soil leaching technology, and bioremediation technology. Among them, photodegradation technology has the advantages of non-toxicity, rapid and efficient, good selectivity, and low energy consumption. It is one of the more actively studied methods for treating volatile organic compounds. For example, Chinese patent CN111282591A discloses a Sb2S3 / AgI / Ag / BON photocatalyst for soil remediation, which realizes the strategy of promoting the separation of photogenerated carriers by the accompanying electric field of photocatalytic materials by constructing a nanocomposite structure. The micropotential of the metal-semiconductor / core-shell nanocomposite structure with a metal as the core driven by electromagnetic induction is used to enhance the charge separation in the semiconductor photocatalyst, and an external magnetic field is applied to a conventional photocatalytic reactor device to achieve the improvement of the performance of photocatalytic degradation of pollutants. Chinese patent CN108421821A discloses a method for degrading polycyclic aromatic hydrocarbons in soil using a cotton straw biochar-based titanium dioxide photocatalyst, wherein cotton straw biochar is prepared by using cotton straw; the biochar is added to a mixed solution of distilled water and anhydrous ethanol, ultrasonically treated for 1 hour, titanium dioxide is added, and stirred evenly, the mixed solution is transferred to a hydrothermal reactor, and the hydrothermal reactor is placed in a homogeneous reactor, the temperature of the homogeneous reactor is set to 120-210°C, the reaction is continued for 12-24 hours, cooled, centrifuged, and the mixture is transferred to a hydrothermal reactor. The lower sediment is washed with distilled water, dried and ground to obtain cotton straw biochar-based titanium dioxide photocatalyst; the biochar prepared from flower straw is loose and porous, with a large specific surface area, and the cotton straw biochar-based titanium dioxide photocatalyst is applied to the soil, which not only improves the soil texture, but also can adsorb and fix polycyclic aromatic hydrocarbons in the soil due to the distribution of various groups such as phenolic hydroxyl groups, carboxyl groups and acid anhydrides on the surface of the biochar; and coupled with the photocatalytic oxidation effect of titanium dioxide, the polycyclic aromatic hydrocarbon molecules can be degraded into pollution-free small molecules.

[0004] However, the photocatalytic materials used for degrading organic matter in the prior art still have problems such as serious photogenerated electron-hole recombination, low specific surface area, complex preparation process, unstable structure, low degradation efficiency, etc., which directly limit their large-scale promotion and application. In view of this, the purpose of the present invention is to provide a composite photocatalyst with good adsorption performance, stable structure, simple preparation process and large specific surface area to solve the above technical problems. Summary of the invention

[0005] The purpose of the present invention is to provide a zinc oxide / indium oxide porous microsphere and a preparation method thereof, and application thereof in the degradation of soil organic pollutants. The material has high degradation efficiency for organic pollutants, stable structure, large specific surface area, 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 in that it comprises the following steps:

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

[0008] (2) adding the zinc salt, indium salt and sodium acetate weighed in step (1) to a mixed solvent of ethylene glycol / water, and magnetically stirring for 5-10 minutes to form a uniform mixed solution; placing the uniformly mixed solution in a reaction kettle, and reacting in an oven at 150-180° C. for 10-15 hours;

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

[0010] Specifically, the zinc salt is 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 of ethylene glycol / water is (20-50) ml: (10-20) ml;

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

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

[0015] The composite material of zinc oxide-indium oxide prepared in the present application, zinc oxide-indium oxide grows to form nanosheets, and then the nanosheet structure self-assembles to form a porous spherical structure with high porosity, the porous spherical structure has a narrow and long pore structure, a high specific surface area, and strong adsorption performance, which can strongly adsorb organic pollutants under the surface of the nanosheets, and under the action of light, quickly degrade organic pollutants in the soil, thereby improving the degradation efficiency of soil organic matter. In addition, after zinc oxide-indium oxide is composited, it can promote the separation of photogenerated carriers, thereby improving light absorption efficiency and photocatalytic activity. In addition, the preparation process of the present application is simple, the material structure is stable, it is conducive to large-scale production and application, and has practical significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

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

[0018] Attached Figure 2 For attachment Figure 1 A partial enlarged view of . DETAILED DESCRIPTION

[0019] Example 1

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

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

[0022] (2) adding 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 magnetically stirring for 10 min to form a uniform mixed solution; placing the uniformly mixed solution in a reaction kettle, and reacting it in an oven at 180° C. for 10 h;

[0023] (3) cooling the solution obtained in step (2) naturally, centrifuging to obtain the product, and washing the product three times with ethanol and deionized water alternately;

[0024] (4) The washed material is 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, comprising the following steps:

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

[0028] (2) adding 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 magnetically stirring for 10 min to form a uniform mixed solution; placing the uniformly mixed solution in a reaction kettle, and reacting it in an oven at 150° C. for 10 h;

[0029] (3) cooling the solution obtained in step (2) naturally, centrifuging to obtain the product, and washing the product three times with ethanol and deionized water alternately;

[0030] (4) The washed material is 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 in that it specifically comprises the following steps:

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

[0034] (2) adding 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 magnetically stirring for 10 min to form a uniform mixed solution; placing the uniformly mixed solution in a reaction kettle, and reacting it in an oven at 150° C. for 10 h;

[0035] (3) cooling the solution obtained in step (2) naturally, centrifuging to obtain the product, and washing the product three times with ethanol and deionized water alternately;

[0036] (4) The washed material is 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 in that it specifically comprises the following steps:

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

[0040] (2) adding 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 magnetically stirring for 10 min to form a uniform mixed solution; placing the uniformly mixed solution in a reaction kettle, and reacting it in an oven at 150° C. for 10 h;

[0041] (3) cooling the solution obtained in step (2) naturally, centrifuging to obtain the product, and washing the product three times with ethanol and deionized water alternately;

[0042] (4) The washed material is 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 in that it specifically comprises the following steps:

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

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

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

[0048] Comparative Example 2

[0049] A method for preparing a material for degrading organic matter in soil, characterized in that it specifically comprises the following steps:

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

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

[0052] (3) cooling the solution obtained in step (2) naturally, centrifuging to obtain the product, and washing the product three times with ethanol and deionized water alternately;

[0053] (4) The washed material is 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 of Example 1 and Comparative Examples 1-2 was tested, and the results are shown in Table 1.

[0055] Organic pollutant degradation test experiment:

[0056] Weigh 3kg of a contaminated soil sample with an atrazine content of 5% and divide it into 6 parts. Weigh 30g of the material of Example 1-4 or Comparative Example 1-2, mix them evenly with the contaminated soil sample, irradiate the mixed sample with a 20w ultraviolet lamp, and turn the soil over again every 60min. Test the soil remediation effect after 24h. Use the same method to test the remediation effect of Example 1-4 and Comparative Example 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] It can be seen from the above table that the specific surface area of ​​the indium oxide / zinc oxide porous microsphere composite material is larger than that of the single indium oxide or zinc oxide material, and its photodegradation efficiency is higher than the photocatalytic performance when it acts alone.

[0060] The embodiments described above are merely descriptions of preferred implementation modes 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 changes. However, as long as they do not deviate 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: The steps include: (1) Weigh 1-3 mmol of zinc salt, 1-3 mmol of indium salt, and 2-5 mmol of 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 magnetically stirring for 5-10 minutes to form a uniform mixed solution; placing the uniformly mixed solution in a reaction kettle, and reacting in an oven at 150-180° C. for 10-15 hours; (3) cooling the solution obtained in step (2) naturally, centrifuging to obtain a product, and washing the product with ethanol and deionized water alternately; (4) The washed material is placed in a tube furnace and calcined at a constant temperature of 300-400 degrees Celsius for 1-2 hours to obtain a zinc oxide-indium oxide composite material.

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

3. According to the method for preparing a material for degrading organic matter in soil according to claim 1, 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 volume of ethylene glycol / water is (20-50) ml: (10-20) ml.

5. According to the method for preparing a material for degrading organic matter in soil according to claim 1, the zinc oxide-indium oxide material is a porous microsphere formed by self-assembly of zinc oxide-indium oxide nanosheets.

6. A material for degrading organic matter in soil, characterized in that: The method is prepared by any one of claims 1 to 5.

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