Preparation method and application of nickel-iron bimetal persulfate soil remediation material

Abstract

The invention discloses a preparation method and application of a nickel-iron bimetal persulfate soil remediation material, the remediation material takes submicron rhombic composite particles of nickel oxide and ferroferric oxide as active components, sodium persulfate or potassium persulfate as an oxidant, and a mixture of starch and fructose as an adhesive, and the nickel-iron bimetal persulfate soil remediation material is prepared by compounding the active components and the oxidant. Hydroxypropyl methyl cellulose is used as a coating agent, and tetrahydrofurfuryl alcohol is used as an active component morphology control agent; on the basis of the mass of the oxidizing agent, the mass percentage content of the active component is 20-30%, the mass percentage content of the adhesive is 5-10%, and the mass percentage content of the coating agent is 10-20%. The preparation method comprises the following steps: firstly, preparing submicron rhombic composite particles of nickel oxide and ferroferric oxide as an active component by a hydrothermal method, and mixing the active component with an oxidizing agent by using an adhesive to prepare particles, wherein the submicron rhombic composite particles of nickel oxide and ferroferric oxide are used as the active component, and the iron-cobalt bimetallic oxide nanofibers are used as the active component; and finally, coating with a coating agent to form the nickel-iron bimetal persulfate soil remediation material. The remediation material is simple in process, low in price and high in durability, can achieve efficient removal of soil pollution heavy organic matter, and has high economic value and wide market application prospects.

Description

Technical Field

[0001] The invention relates to a preparation method and application of a nickel-iron bimetallic persulfate soil remediation material, and belongs to the field of soil remediation. Background Art

[0002] Common remediation technologies for organic pollution at home and abroad include chemical oxidation / reduction, cement kiln co-treatment, leaching, gas phase extraction, bioremediation, etc. Chemical oxidation technology refers to adding chemical oxidants to the contaminated site to cause the pollutants in the soil to oxidize with the oxidants, and finally render the pollutants in the contaminated site harmless. It is widely used because of its thorough degradation of organic pollutants and short remediation cycle. Chemical oxidation technology is relatively mature in the treatment of organic contaminated site pollution, and a complete process system has been formed at home and abroad. Patent CN110961451B discloses a soil remediation material and soil remediation method for oxidative degradation of organic pollutants. Peroxide is used as an oxidant, and the occurrence of peroxidation is avoided by adding stabilizers and activators, which can effectively remove organic pollutants in the soil. Patent CN116355621A discloses a remediation material and remediation method for organic contaminated soil coupled with zero-valent iron and chlorine dioxide, which can not only effectively remove organic pollutants, but also provide trace iron elements to the soil and increase soil fertility.

[0003] The above solutions all have good effects in specific fields, but their application fields are single, and the oxidant persulfate has strong oxidizing properties. After being left in the air for too long, it will decompose and cause performance degradation, which cannot meet the requirements of long-term transportation of the agent. Therefore, it is very necessary to develop a soil remediation agent that can be stably stored and has the ability to efficiently oxidize organic pollutants. Summary of the invention

[0004] The purpose of the present invention is to solve the problem that soil remediation materials can be stably stored and efficiently oxidized during the remediation of organic contaminated soil. Another purpose of the present invention is to provide a method for preparing a nickel-iron bimetallic persulfate soil remediation material.

[0005] The present invention can be realized through the following technical scheme: the repair material uses submicron rhombic composite particles of nickel oxide and ferroferric oxide as active components, persulfate as oxidant, a mixture of starch and fructose as adhesive, hydroxypropyl methylcellulose as coating agent, and tetrahydrofurfuryl alcohol as active component morphology control agent. In the catalyst design, nickel oxide and ferroferric oxide not only have excellent redox properties, but also nickel oxide has excellent CC bond breaking properties. In addition, tetrahydrofurfuryl alcohol is used as a morphology control agent to grow the active component into a submicron rhombic structure, which can not only increase the contact between the catalyst surface and the reaction molecules, thereby promoting the activation of organic pollution molecules, and ultimately improve the organic polluted soil repair effect; in addition, ferroferric oxide has magnetism, and after soil repair, it can be decided whether to use leaching and magnetic separation to recycle the active components according to needs; persulfate has excellent oxidation performance, and can deeply oxidize organic pollution molecules under the catalytic promotion of nickel oxide and ferroferric oxide; persulfate Due to its excellent oxidizing properties, acid salts will gradually decompose during their existence, resulting in a decrease in performance during use. The mixed adhesive of starch and fructose can fully mix the active component with persulfate, and use hydroxypropyl methylcellulose to coat the active component and oxidant, thereby avoiding contact between the oxidant and the air; the role of starch and fructose is to mix the active component and the oxidant in the expected proportion and prepare them into spheres for easy coating with hydroxypropyl methylcellulose. At the same time, hydroxypropyl cellulose, starch and fructose will not only dissolve in water during use so as not to affect the use of soil remediation materials, but can also be gradually oxidized in natural soil to form organic fertilizers, thereby enhancing soil fertility.

[0006] The present invention can be achieved through the following technical scheme: the repair material uses submicron rhombus composite particles of nickel oxide and ferrosoferric oxide as active components, persulfate as an oxidant, a mixture of starch and fructose as an adhesive, hydroxypropyl methylcellulose as a coating agent, and tetrahydrofurfuryl alcohol as an active component morphology control agent; based on the mass of the oxidant, the mass percentage of the active component is 20-30%, the mass percentage of the adhesive is 5-10%, and the mass percentage of the coating agent is 10-20%. The preparation method of the material comprises the following steps:

[0007] (1) Preparation of nickel-iron submicron rhombic composite particles

[0008] The nickel salt, the iron salt, the active component morphology control agent and the deionized water are uniformly mixed, and then placed in a hydrothermal reactor for hydrothermal reaction, filtered and dried after the reaction is completed, and then calcined at high temperature to obtain nickel-iron submicron rhombus composite particles;

[0009] (2) Preparation of spherical particles

[0010] The starch, fructose and deionized water are mixed to prepare a binder slurry, and then the persulfate and the nickel-iron submicron rhombus composite particles obtained in step (1) are weighed, stirred evenly and placed in the binder slurry for stirring, and after being stirred evenly, placed in an oven for drying, and after drying, the mixture is formed into spherical particles and sieved to obtain mixed spherical particles of the persulfate and the nickel-iron submicron rhombus composite particles;

[0011] (3) Preparation of soil remediation materials

[0012] Hydroxypropyl methylcellulose is dissolved in deionized water and stirred to form a hydroxypropyl methylcellulose solution. The mixed spherical particles obtained in step (2) are then placed in the hydroxypropyl methylcellulose solution for 5 to 10 seconds and then taken out and dried. The particles are repeatedly placed in the hydroxypropyl methylcellulose solution and dried until the hydroxypropyl methylcellulose solution is used up, thereby obtaining a soil remediation material.

[0013] In the technical solution of the present invention, the mass ratio of nickel oxide to ferrosoferric oxide is 1:(0.5-1).

[0014] In the technical scheme of the present invention: the nickel salt described in step (1) is nickel nitrate hexahydrate or nickel chloride hexahydrate, the iron salt is ferric nitrate nonahydrate or ferric chloride hexahydrate, and the active component morphology control agent is tetrahydrofurfuryl alcohol.

[0015] In the technical solution of the present invention: the mass ratio of the nickel salt, the active component morphology control agent and the deionized water in step (1) is 1: (0.05-0.1): (40-60).

[0016] In the technical scheme of the present invention: the temperature of the hydrothermal reaction in step (1) is 160-180°C, the time of the hydrothermal reaction is 6-12h, the temperature of the drying is 80-100°C, the time of the drying is 4-6h, the temperature of the high-temperature roasting is 500-700°C, and the time of the high-temperature roasting is 2-4h.

[0017] In the technical solution of the present invention: in step (2), the mass ratio of starch, fructose and deionized water is 1: (0.1-0.3): (1-2).

[0018] In the technical solution of the present invention: the persulfate described in step (2) is sodium persulfate or potassium persulfate.

[0019] In the technical solution of the present invention: the drying temperature in step (2) is 20-30° C., the drying time is 12-24 hours, and the metal mesh screens used for screening are 5 mesh and 7 mesh.

[0020] In the technical solution of the present invention: the mass ratio of hydroxypropyl methylcellulose and deionized water in step (3) is (3-5):100, the drying temperature is 20-40° C., and the drying time is 4-6 hours.

[0021] In the technical solution of the present invention, the nickel-iron bimetallic persulfate soil remediation material prepared by the method is used in the remediation of soil organic pollutants.

[0022] Furthermore, the organic matter is chlorobenzene or polychlorinated biphenyls.

[0023] Beneficial effects:

[0024] (1) The repair material uses submicron rhombic composite particles of nickel oxide and ferrosoferric oxide as active components, which can promote the decomposition of organic pollutants.

[0025] (2) The mixture of starch and fructose can mix the active components and the oxidant in proportion, which is conducive to the direct use of soil remediation materials during use without having to mix them on site.

[0026] (3) Starch, fructose and hydroxypropyl methylcellulose can prevent the soil remediation materials from being gradually oxidized after preparation, which affects their effects. In addition, the binders and coating agents can be oxidized in the natural environment after entering the soil, thereby increasing soil fertility.

[0027] (4) The raw materials of this repair material are easily available, the process is simple, the pollutant removal efficiency is high, the removal range is wide, and it has high economic value and broad market application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Attached Figure 1 FE-SEM image of the active component prepared in Example 1;

[0029] Attached Figure 2 FE-SEM image of the active component prepared in Comparative Example 1. DETAILED DESCRIPTION

[0030] The following examples further illustrate the preparation method of the nickel-iron bimetallic persulfate soil remediation material of the present invention. The examples are implemented based on the technical solution of the present invention, and detailed implementation methods and specific operation processes are given, but the protection scope of the present invention is not limited to the following examples.

[0031] The experimental methods in the following examples, unless otherwise specified, are all conventional methods in the art, and the experimental devices and experimental materials, unless otherwise specified, are all commercially available.

[0032] Performance evaluation: Weigh 10g of soil remediation material and 100g of contaminated clay soil (polychlorinated biphenyl or chlorobenzene content in the soil: 2%) and mix them thoroughly. Then weigh 200g of deionized water and add it to the soil. After standing for 2h, filter to obtain soil residue and filtered water. Use liquid chromatography to determine the content of organic pollutants in the filtered water, and calculate the organic pollutant removal rate.

[0033] Example 1

[0034] (1) Preparation of nickel-iron submicron rhombic composite particles

[0035] 3.89g nickel nitrate hexahydrate, 5.23g ferric nitrate nonahydrate, 0.19g tetrahydrofurfuryl alcohol, and 155.60g deionized water were mixed evenly, and then placed in a hydrothermal reactor for hydrothermal reaction at 160°C for 12h. After the reaction was completed, the mixture was filtered and dried at 80°C for 6h, and then calcined at 500°C for 4h to obtain nickel-iron submicron rhombic composite particles ( Figure 1 );

[0036] (2) Preparation of spherical particles

[0037] Weigh 0.91 g starch, 0.09 g fructose and 0.91 g deionized water and mix them to prepare a binder slurry, then weigh 10 g sodium persulfate and mix them with the nickel-iron submicron rhombic composite particles obtained in step (1), stir them evenly and place them in the binder slurry for stirring, after stirring evenly, place them in an oven at 20° C. and dry them for 24 h, after drying, prepare the mixture into spherical particles and sieve them through a 5-mesh sieve and a 7-mesh sieve to obtain mixed spherical particles of persulfate and nickel-iron submicron rhombic composite particles with a size of 2.8 to 4.0 mm;

[0038] (3) Preparation of soil remediation materials

[0039] 1 g of hydroxypropyl methylcellulose is dissolved in 20 g of deionized water and stirred to form a hydroxypropyl methylcellulose solution, and then the mixed spherical particles obtained in step (2) are placed in the hydroxypropyl methylcellulose solution for 5 to 10 seconds and then taken out, placed in an oven at 20° C. and dried for 6 hours, and repeatedly placed in the hydroxypropyl methylcellulose solution and dried until the hydroxypropyl methylcellulose solution is used up, thereby preparing a soil remediation material;

[0040] (4) Performance evaluation

[0041] Weigh 10g of soil remediation material and 100g of contaminated clay soil (chlorobenzene content in the soil: 2%) and mix them thoroughly. Then weigh 200g of deionized water and add it to the soil. After standing for 2h, filter to obtain soil residue and filtered water. Use liquid chromatography to determine the content of organic pollutants in the filtered water, and calculate the organic pollutant removal rate. The sample has an organic pollutant removal rate of 99.4%.

[0042] Example 2

[0043] (1) Preparation of nickel-iron submicron rhombic composite particles

[0044] 6.36 g of nickel chloride hexahydrate, 3.50 g of ferric chloride hexahydrate, 0.64 g of tetrahydrofurfuryl alcohol and 381.6 g of deionized water were mixed evenly, and then placed in a hydrothermal reactor for hydrothermal reaction at 180° C. for 6 h. After the reaction was completed, the mixture was filtered and dried at 100° C. for 4 h, and then calcined at 700° C. for 2 h to obtain nickel-iron submicron rhombic composite particles;

[0045] (2) Preparation of spherical particles

[0046] Weigh 0.36 g starch, 0.14 g fructose and 0.72 g deionized water and mix them to prepare a binder slurry, then weigh 10 g sodium persulfate and the nickel-iron submicron rhombic composite particles obtained in step (1), stir them evenly and place them in the binder slurry for stirring, after stirring evenly, place them in an oven at 30° C. and dry them for 124 h, after drying, prepare the mixture into spherical particles and sieve them through a 5-mesh sieve and a 7-mesh sieve to obtain mixed spherical particles of persulfate and nickel-iron submicron rhombic composite particles with a size of 2.8 to 4.0 mm;

[0047] (3) Preparation of soil remediation materials

[0048] 2 g of hydroxypropyl methylcellulose is dissolved in 66.67 g of deionized water and stirred to form a hydroxypropyl methylcellulose solution, and then the mixed spherical particles obtained in step (2) are placed in the hydroxypropyl methylcellulose solution for 5 to 10 seconds and then taken out, placed in an oven at 40° C. and dried for 4 hours, and repeatedly placed in the hydroxypropyl methylcellulose solution and dried until the hydroxypropyl methylcellulose solution is used up, thereby preparing a soil remediation material;

[0049] (4) Performance evaluation

[0050] Weigh 10g of soil remediation material and 100g of contaminated clay soil (polychlorinated biphenyl content in the soil: 2%) and mix them thoroughly. Then weigh 200g of deionized water and add it to the soil. After standing for 2h, filter to obtain soil residue and filtered water. Use liquid chromatography to determine the content of organic pollutants in the filtered water, and calculate the organic pollutant removal rate. The sample has an organic pollutant removal rate of 96.4%.

[0051] Comparative Example 1

[0052] (1) Preparation of soil remediation materials

[0053] Except that tetrahydrofurfuryl alcohol is not used as a morphology control agent when preparing the soil remediation material, other conditions are the same as those in Example 1;

[0054] (2) Performance evaluation

[0055] Weigh 10g of soil remediation material and 100g of contaminated clay soil (chlorobenzene content in the soil: 2%) and mix them thoroughly. Then weigh 200g of deionized water and add it to the soil. After standing for 2h, filter to obtain soil residue and filtered water. Use liquid chromatography to determine the content of organic pollutants in the filtered water, and calculate the organic pollutant removal rate. The sample has an organic pollutant removal rate of 48.3%.

[0056] (3) Contrast effect

[0057] Compared with Example 1, when preparing the soil remediation material, tetrahydrofurfuryl alcohol is not used as a morphology control agent, and the active component will form a micron-sized block structure ( Figure 2 ), although the surface is porous, the contact area with the reaction molecules is reduced compared with the submicron rhombus structure, and the organic matter removal efficiency is significantly reduced.

[0058] Comparative Example 2

[0059] (1) Preparation of soil remediation materials

[0060] Except that starch and fructose are not used as adhesives in the preparation of soil remediation materials, other conditions are the same as those in Example 2; (2) Comparative Effect

[0061] Compared with Example 2, starch and fructose are not used as adhesives in the preparation of the soil remediation material. Hydroxypropyl methylcellulose has difficulty wrapping the mixture of active components and oxidants into spherical particles, mainly because the oxidant persulfate will quickly dissolve in the hydroxypropyl methylcellulose solution.

[0062] Although the above describes the specific implementation methods of the present invention, it does not limit the scope of protection of the present invention. Based on the technical solution of the present invention, various modifications or variations that can be made by those skilled in the art without creative work are still within the scope of protection of the present invention.

Claims

1. A method for preparing a nickel-iron bimetallic persulfate soil remediation material, characterized in that: The repair material uses submicron rhombic composite particles of nickel oxide and ferrosoferric oxide as active components, persulfate as an oxidant, a mixture of starch and fructose as an adhesive, hydroxypropyl methylcellulose as a coating agent, and tetrahydrofurfuryl alcohol as an active component morphology control agent; based on the mass of the oxidant, the mass percentage of the active component is 20-30%, the mass percentage of the adhesive is 5-10%, and the mass percentage of the coating agent is 10-20%. The preparation method of the material comprises the following steps: (1) Preparation of nickel-iron submicron rhombic composite particles The nickel salt, the iron salt, the active component morphology control agent and the deionized water are uniformly mixed, and then placed in a hydrothermal reactor for hydrothermal reaction, filtered and dried after the reaction is completed, and then calcined at high temperature to obtain nickel-iron submicron rhombus composite particles; (2) Preparation of spherical particles The starch, fructose and deionized water are mixed to prepare a binder slurry, and then the persulfate and the nickel-iron submicron rhombus composite particles obtained in step (1) are weighed, stirred evenly and placed in the binder slurry for stirring, and after being stirred evenly, placed in an oven for drying, and after drying, the mixture is formed into spherical particles and sieved to obtain mixed spherical particles of the persulfate and the nickel-iron submicron rhombus composite particles; (3) Preparation of soil remediation materials Hydroxypropyl methylcellulose is dissolved in deionized water and stirred to form a hydroxypropyl methylcellulose solution. The mixed spherical particles obtained in step (2) are then placed in the hydroxypropyl methylcellulose solution for 5 to 10 seconds and then taken out and dried. The particles are repeatedly placed in the hydroxypropyl methylcellulose solution and dried until the hydroxypropyl methylcellulose solution is used up, thereby obtaining a soil remediation material.

2. The preparation method according to claim 1, characterized in that: The mass ratio of nickel oxide to ferrosoferric oxide is 1:(0.5-1).

3. The preparation method according to claim 1, characterized in that: The nickel salt described in step (1) is nickel nitrate hexahydrate or nickel chloride hexahydrate, the iron salt is ferric nitrate nonahydrate or ferric chloride hexahydrate, and the active component morphology control agent is tetrahydrofurfuryl alcohol.

4. The preparation method according to claim 1, characterized in that: The mass ratio of the nickel salt, the active component morphology control agent and the deionized water in step (1) is 1:(0.05-0.1):(40-60).

5. The preparation method according to claim 1, characterized in that: The temperature of the hydrothermal reaction in step (1) is 160-180° C., the time of the hydrothermal reaction is 6-12 hours, the temperature of the drying is 80-100° C., the time of the drying is 4-6 hours, the temperature of the high-temperature roasting is 500-700° C., and the time of the high-temperature roasting is 2-4 hours.

6. The preparation method according to claim 1, characterized in that: In step (2), the mass ratio of starch, fructose and deionized water is 1:(0.1-0.3):(1-2).

7. The preparation method according to claim 1, characterized in that: The persulfate described in step (2) is sodium persulfate or potassium persulfate.

8. The preparation method according to claim 1, characterized in that: The drying temperature in step (2) is 20-30° C., the drying time is 12-24 hours, and the metal mesh screens used for screening are 5-mesh and 7-mesh.

9. The preparation method according to claim 1, characterized in that: The mass ratio of hydroxypropyl methylcellulose and deionized water in step (3) is (3-5):100, the drying temperature is 20-40° C., and the drying time is 4-6 hours.

10. Application of the nickel-iron bimetallic persulfate soil remediation material prepared by the method of claim 1 in the remediation of organic pollutants in soil.

11. The use according to claim 10, characterized in that: The organic pollutants are chlorobenzene and polychlorinated biphenyls.

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