Preparation method, product and application of yttrium iron oxide loaded biochar composite material

Abstract

The present invention relates to the technical field of biochar material preparation, and in particular to a preparation method, product, and application of an yttrium iron oxide-loaded biochar composite material. The present invention uses oxytetracycline residue to prepare biochar, on which yttrium iron oxide is loaded, and calcined at high temperature under an inert atmosphere to prepare the composite material, which has obvious magnetic properties, solves the problem of material recovery difficulties, and promotes the recycling performance of the composite material. The adsorption experiment results of CTC show that the yttrium iron oxide-loaded biochar composite material can effectively adsorb CTC and is an ideal material for a high-efficiency adsorbent.

Description

Technical Field

[0001] The present invention relates to the technical field of biochar material preparation, and in particular to a preparation method, product and application of an yttrium iron oxide loaded biochar composite material. Background Art

[0002] Chlortetracycline (CTC) is one of the types of tetracycline antibiotic (TCs) residues in wastewater. It is widely used in the treatment of human diseases and animal husbandry due to its broad antibacterial spectrum, good efficacy, low cost and good safety. However, antibiotics cannot be completely absorbed or metabolized by organisms. Nearly 80% of antibiotics that cannot be metabolized will be excreted from the body in the form of active substances and eventually enter the ecological environment. The long-term presence of antibiotics in the environment may threaten human health through toxic effects. At the same time, the accumulation of discarded antibiotics from different sources in groundwater, surface water and wastewater will induce the evolution of antibiotic resistance genes, increasing the potential risk to the ecosystem. Therefore, the development of an efficient CTC treatment process is very important and necessary.

[0003] Adsorption is the preferred method for treating chlortetracycline residues in wastewater due to its high efficiency, low cost, and lack of toxic byproducts. Traditional adsorption materials primarily include activated carbon, biochar, metal oxides, and graphene oxide. These materials are sourced from a wide range of sources. For example, biochar is often made from agricultural products such as peanut shells, chili stalks, and potato peels. This approach is not only cost-effective but also allows for waste resource utilization. Biochar is a type of carbon-rich material with a highly developed pore structure, a loose and porous surface, a large specific surface area, and a large number of organic functional groups. In recent years, due to its unique physicochemical properties, it has been widely used in environmental remediation. In the environmental field, biochar can effectively remove a variety of organic and inorganic pollutants and is therefore widely used to fix and remove pollutants in water and soil. Biochar also plays a role in reducing carbon emissions and mitigating climate change. However, the adsorption and removal efficiency of biochar materials for CTC in wastewater needs to be further improved. Summary of the Invention

[0004] Based on the above, the present invention provides a method for preparing a yttrium-iron oxide-loaded biochar composite material, as well as its product and application. This method uses oxytetracycline residue to prepare biochar, which is then loaded with yttrium-iron oxide. The composite material is then calcined at high temperature under an inert atmosphere to produce a material with significant magnetic properties, addressing the difficulty of material recycling and promoting the composite material's recyclability.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] One of the technical solutions of the present invention is a method for preparing a yttrium iron oxide-loaded biochar composite material, comprising the following steps:

[0007] The fungus residue powder is soaked in a mixed acid solution, and then rinsed, dried, and calcined to obtain biochar;

[0008] dissolving yttrium salt and iron salt in water to obtain a mixed salt solution;

[0009] dropping the mixed salt solution into boiling water and boiling the water to obtain a sol;

[0010] adding an alkaline solution to the sol to produce precipitation and stirring, then adding the biochar, mixing, filtering, rinsing, and drying to obtain a solid;

[0011] calcining the solid to obtain the yttrium iron oxide-loaded biochar composite material;

[0012] The fungus residue powder is prepared by drying, crushing and grinding the oxytetracycline fungus residue.

[0013] The second technical solution of the present invention is a yttrium iron oxide loaded biochar composite material prepared according to the above preparation method.

[0014] The third technical solution of the present invention is the use of the above-mentioned yttrium iron oxide loaded biochar composite material in the adsorption of chlortetracycline in wastewater.

[0015] The present invention discloses the following technical effects:

[0016] (1) The present invention loads yttrium ferrite onto a biochar material and calcines it at high temperature under an inert atmosphere to prepare a magnetic composite material. Yttrium ferrite nanoparticles are loaded onto the surface of a biochar material with a large specific surface area, and the two are stacked on the biochar surface to form a composite material with certain characteristics. The pore structure and particle bridges formed after oxygen-free high-temperature calcination greatly increase the specific surface area of ​​the adsorbent and its adsorption capacity for CTC in wastewater.

[0017] (2) The method of the present invention uses biochar as a precursor and regulates the metal oxide loading. The iron oxide formed after calcination makes the catalyst magnetic. The functionalization treatment of biochar (i.e., the loading of metal oxides) enhances the adsorption activity of the overall adsorbent, making it magnetic, and modifies the surface charge properties of biochar, forming more functional groups and a larger specific surface area, exposing more adsorption sites, and having a good adsorption effect even at a low dosage, thereby achieving the purpose of efficiently adsorbing CTC in water.

[0018] (3) The yttrium iron oxide-loaded biochar composite material prepared by the method of the present invention has both excellent adsorption performance and high magnetism. Compared with the existing technology, it improves the adsorption performance while also having recyclability. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 X-ray diffraction spectra of the YFeO3 / BC composite materials prepared in Examples 1-2 of the present invention, the BC prepared in Comparative Example 1, and the YFeO3 prepared in Comparative Example 2;

[0021] Figure 2 This is the adsorption isotherm of CTC by YFeO3 / BC-1:1 prepared in Example 1 of the present invention;

[0022] Figure 3 The adsorption capacity of CTC by YFeO3 / BC-1:1 prepared in Example 1 of the present invention, BC prepared in Comparative Example 1, and YFeO3 prepared in Comparative Example 2;

[0023] Figure 4 The adsorption performance of the YFeO3 / BC composite material prepared in Example 1-2 of the present invention;

[0024] Figure 5 This is the recycling result of YFeO3 / BC-1:1 prepared in Example 1 of the present invention;

[0025] Figure 6 This is the TEM image of YFeO3 / BC-1:1 prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0026] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0027] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value within any stated value or stated range, and each smaller range between any other stated value or intermediate value within the stated range, is also encompassed within the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0028] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0029] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be exemplary only.

[0030] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0031] Unless otherwise specified, the "%" in the present invention refers to mass percentage.

[0032] A first aspect of the present invention provides a method for preparing a yttrium iron oxide-loaded biochar composite material, comprising the following steps:

[0033] The fungus residue powder is soaked in a mixed acid solution, and then rinsed, dried, and calcined to obtain biochar;

[0034] dissolving yttrium salt and iron salt in water to obtain a mixed salt solution;

[0035] dropping the mixed salt solution into boiling water and boiling the water to obtain a sol;

[0036] adding an alkaline solution to the sol to produce precipitation and stirring, then adding the biochar, mixing, filtering, rinsing, and drying to obtain a solid;

[0037] calcining the solid to obtain the yttrium iron oxide-loaded biochar composite material;

[0038] The fungus residue powder is prepared by drying, crushing and grinding the oxytetracycline fungus residue.

[0039] The present invention has no particular limitation on the usage ratio of the mushroom residue powder and the mixed acid solution, and the usage of the mixed acid solution only needs to be sufficient to fully immerse the mushroom residue powder.

[0040] In a preferred embodiment of the present invention, the mixed acid solution is a mixed solution of HF and HCl; the mass fraction of HF in the mixed acid solution is 0.9% to 2.2%, and the mass fraction of HCl is 1.48% to 1.55%. The soaking time is 2 hours. The purpose of soaking is to remove organic components such as carbohydrates and proteins contained in the fungus residue.

[0041] In the present invention, the rinsing is performed three times with deionized water; and the flushing is performed with distilled water until the solution is neutral.

[0042] In a preferred embodiment of the present invention, when preparing biochar, the calcination temperature is 400° C. and the calcination time is 3 hours.

[0043] In a preferred embodiment of the present invention, the yttrium salt is Y(NO3)3·6H2O; the iron salt is Fe(NO3)3·9H2O; the concentration of the yttrium salt in the mixed salt solution is 0.15 mol / L; and the molar ratio of the yttrium salt to the iron salt is 1:1.

[0044] In the actual preparation process, the weighing ratio of yttrium salt and iron salt may be slightly different, and it is sufficient to ensure that the molar ratio of the two is approximately 1:1.

[0045] In a preferred embodiment of the present invention, the boiling time is 15 minutes; the alkaline solution is a 5% by mass K2CO3 solution; and the amount of alkaline solution added is sufficient to turn phenolphthalein test paper red. In the present invention, stirring is performed for 1 hour after the addition of the alkaline solution to cause precipitation, the purpose of stirring is to accelerate the precipitation of the resulting composite material.

[0046] In a preferred embodiment of the present invention, the amount of biochar added is 0.25 to 2 times the mass of yttrium ferrite generated by the yttrium salt and the iron salt.

[0047] In a preferred embodiment of the present invention, when the solid is calcined, the calcination conditions are: calcination at 700° C. for 3 hours under an inert atmosphere.

[0048] The second technical solution of the present invention is a yttrium iron oxide loaded biochar composite material prepared according to the above preparation method.

[0049] The third technical solution of the present invention is the use of the above-mentioned yttrium iron oxide loaded biochar composite material in the adsorption of chlortetracycline in wastewater.

[0050] In a preferred embodiment of the present invention, the above-mentioned yttrium iron oxide-loaded biochar composite material is added to the wastewater; the addition amount of the yttrium iron oxide-loaded biochar composite material in the wastewater is 0.05 g / L; and the concentration of chlortetracycline in the wastewater is 10 to 200 mg / L.

[0051] The adsorption experimental results of CTC showed that the yttrium iron oxide loaded biochar composite material can effectively adsorb CTC and is an ideal material for high-efficiency adsorbent.

[0052] Unless otherwise specified, the technical solutions described in the present invention are all conventional solutions in the field, and the reagents or raw materials used, unless otherwise specified, are purchased from commercial channels or have been disclosed.

[0053] The oxytetracycline residue used in the examples of the present invention comes from Inner Mongolia Autonomous Region, China.

[0054] The mass fraction of the HCl solution used in the embodiment of the present invention is 36% to 38%;

[0055] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0056] Example 1

[0057] This embodiment provides a method for preparing a yttrium iron oxide-loaded biochar composite material (YFeO3 / BC-1:1), the steps are as follows:

[0058] S1: Dry the oxytetracycline residue, crush it, grind it, and sieve it to obtain a powder for later use.

[0059] S2: 44.65 mL of 55% HF solution and 80.71 mL of HCl solution were measured and adjusted to 2 L respectively. The treated fungus residue powder was weighed and added to the above solutions to soak for 2 h. The mixture was rinsed three times with distilled water, dried, and calcined in a tube furnace at 400°C for 3 h to prepare biochar, which was recorded as BC.

[0060] S3: Symmetrically take 2.87g Y(NO3)3·6H2O and 3.03g Fe(NO3)3·9H2O and dissolve them in 50mL distilled water to prepare a mixed salt solution, and stir to fully dissolve them.

[0061] S4: Slowly drop the above solution into 500 mL of continuously boiling water and boil for 15 minutes. Stop boiling when a yellow-brown sol appears.

[0062] S5: Add 5% K2CO3 solution to the solution in step S4 until the phenolphthalein test paper turns red. After precipitation occurs, stir magnetically for 1 hour, add 1.4475g BC, stir evenly, cool to room temperature, filter, rinse with distilled water until pH ≈ 7, dry and grind to obtain a yellow-brown solid.

[0063] S6: The yellow-brown solid obtained in step S5 was calcined at 700°C for 3 h in a tube furnace under a nitrogen atmosphere to obtain a YFeO3 / BC composite material with a mass ratio of YFeO3 to BC of approximately 1:1, labeled as YFeO3 / BC-1:1. Its X-ray diffraction spectrum is as follows: Figure 1 As shown. Figure 1 It can be seen that the prepared composite material has characteristic diffraction peaks of YFeO3 and BC, which indicates the successful preparation of YFeO3 / BC.

[0064] Figure 2 The adsorption isotherm of CTC by YFeO3 / BC-1:1 prepared in Example 1 is shown in FIG. 1 . The relationship between the equilibrium adsorption amount of CTC by YFeO3 / BC-1:1 and the equilibrium concentration is shown in FIG. Figure 2 As shown. Figure 2 It can be seen that after adsorption equilibrium, the CTC concentration decreased from the initial concentrations of 10 mg / L, 30 mg / L, 50 mg / L, 75 mg / L, 100 mg / L, 150 mg / L, and 200 mg / L to 3.64 mg / L, 12.88 mg / L, 17.19 mg / L, 34.67 mg / L, 53.93 mg / L, 91.7 mg / L, and 130.77 mg / L, respectively. The amount of CTC adsorbed by YFeO3 / BC-1:1 increased with increasing initial concentrations (10 mg / L to 200 mg / L). At low concentrations, the adsorption rate of CTC on YFeO3 / BC-1:1 was rapid. As the CTC concentration increased, the adsorption rate slowed, ultimately reaching adsorption saturation at a higher equilibrium adsorption value. The adsorption isotherm test process of CTC by YFeO3 / BC-1:1 is as follows: (at room temperature (25°C), placed in a glass bottle in a constant temperature oscillating box at 150 rpm / min; 200 mL of prepared CTC solutions with different initial concentrations are taken, and 10 mg of adsorbent is added to the solution to start the reaction; after 48 hours of equilibrium, 1 mL of the sample is taken, filtered through a 0.22 μm filter to remove the adsorbent, and detected and analyzed using a high performance liquid chromatography. The experimental conditions are: the initial concentrations of CTC are 10 mg / L, 30 mg / L, 50 mg / L, 75 mg / L, 100 mg / L, 150 mg / L, and 200 mg / L, the solid-liquid ratio is 0.05 g / L, and the pH is 6).

[0065] Comparative Example 1

[0066] In this comparative example, the mushroom residue biochar was prepared as a control catalyst by high-temperature calcination, and the steps were as follows:

[0067] S1: drying the oxytetracycline residue, crushing and grinding it, and then sieving it to obtain a powder for later use;

[0068] S2: 44.65 mL of HF and 80.71 mL of HCl solution were measured and adjusted to 2 L. The treated fungus residue powder was weighed and added to the above solution to soak for 2 h. The mixture was rinsed three times with distilled water, dried, and calcined in a tube furnace at 400 °C for 3 h to prepare biochar, which was recorded as BC.

[0069] Comparative Example 2

[0070] This comparative example provides a chlortetracycline adsorbed by yttrium ferrite, and the preparation method is as follows:

[0071] Weigh 2.87g of Y(NO3)3·6H2O and 3.03g of Fe(NO3)3·9H2O and dissolve them in 50mL of distilled water. Slowly add the solution dropwise to 500mL of boiling water and boil for 15 minutes. Once a yellowish-brown sol appears, stop boiling. Add 5% K2CO3 solution until the phenolphthalein test paper turns red. After a precipitate forms, stir magnetically for 1 hour. Cool to room temperature, filter, rinse with distilled water until neutral, dry, and grind to obtain a yellowish-brown solid. Calcine the solid at 700°C in a tube furnace under a nitrogen atmosphere for 3 hours to obtain the YFeO3 material.

[0072] The adsorption effects of YFeO3 / BC-1:1, BC and YFeO3 prepared in Example 1 and Comparative Example 1 and Comparative Example 2 on chlortetracycline in wastewater as adsorption materials were tested as follows:

[0073] The test was carried out at room temperature (25°C) in a glass bottle placed in a constant temperature shaking box at 150 rpm / min.

[0074] Take 200 mL of the prepared CTC solution and add 10 mg of adsorbent to the solution to start the reaction;

[0075] After 48 h of equilibrium, 1 mL of the sample was taken, filtered through a 0.22 μm filter to remove the adsorbent, and analyzed using a high performance liquid chromatography.

[0076] The experimental conditions were as follows: initial CTC concentration of 50 mg / L, solid-liquid ratio of 0.05 g / L, and pH of 6.

[0077] The results are as follows Figure 3 As shown by Figure 3It can be seen that the equilibrium adsorption capacity of BC for CTC in Comparative Example 1 is only 7.62 mg / g, the equilibrium adsorption capacity of YFeO3 adsorbent for CTC in Comparative Example 2 is 64.05 mg / g, and the equilibrium adsorption capacity of YFeO3 / BC-1:1 for CTC in Example 1 can reach 355.49 mg / g. Compared with single BC or YFeO3, the adsorption performance of YFeO3 / BC-1:1 prepared by compounding BC and YFeO3 has been greatly improved, indicating that the YFeO3 / BC composite material can adsorb CTC more efficiently, and the yttrium ferrite loading changes the physical and chemical properties of biochar and improves the adsorption performance of pollutants.

[0078] Example 2

[0079] This example investigates the effect of different mass ratios of yttrium ferrite (YFeO3) to biochar (BC) on the adsorption properties of YFeO3 / BC composite materials. The preparation methods of YFeO3 / BC composite materials with different mass ratios of yttrium ferrite (YFeO3) to biochar (BC) are as follows:

[0080] The only difference from Example 1 is that the amount of BC added in step S5 is adjusted so that the mass ratio of YFeO3 and BC in the YFeO3 / BC composite material is approximately 2:1, 4:1, 9:1, and 1:2. The obtained YFeO3 / BC composite materials are correspondingly marked as YFeO3 / BC-2:1, YFeO3 / BC-4:1, YFeO3 / BC-9:1, and YFeO3 / BC-1:2.

[0081] YFeO3 / BC-2:1, YFeO3 / BC-4:1, YFeO3 / BC-9:1 and YFeO3 / BC-1:2 prepared in Example 2 were used as adsorption materials to test their adsorption effect on chloramphenicol in wastewater, and the testing method was the same as that in Example 1.

[0082] The results are as follows Figure 4 As shown in the figure, when the mass ratio of YFeO3 and BC is different, different adsorption effects are shown in the process of adsorbing CTC under the same experimental conditions. The adsorption amount of TC by YFeO3 / BC-1:1 can reach 355.49 mg / g, indicating that the composite material has efficient adsorption performance of chlortetracycline.

[0083] Compared with biochar catalyst, the present invention prepares biochar from oxytetracycline residue and loads yttrium iron oxide on this basis to prepare YFeO3 / BC composite material, which not only solves the resource utilization of oxytetracycline residue waste, but also realizes the reuse of yttrium elements in wastewater discharged from industries such as ceramics, thus reducing the preparation cost and alleviating the potential threat to the environment. Figure 5As shown, the adsorption capacity of YFeO3 / BC-1:1 prepared in Example 1 is still 84.97% of the initial amount after three cycles, and it still has good adsorption capacity and high stability.

[0084] like Figure 6 As shown, the yttrium iron oxide particles in the composite material are dispersed on the surface of biochar and stacked on each other to form pores of different sizes, which increases the specific surface area, exposes more adsorption sites, and further improves the adsorption capacity of the composite material.

[0085] This method loads yttrium ferrite onto biochar, highly dispersing the yttrium ferrite particles on the biochar surface. The material is then calcined in a high-temperature, inert environment to produce a magnetic composite material. The resulting composite material, calcined at high temperatures in the absence of oxygen, has nanoscale particles, offering advantages such as small size, high dispersion, and a large specific surface area. Furthermore, the stacking of the particles improves the adsorbent's pore structure and stability, enhancing its adsorption performance.

[0086] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for preparing a yttrium iron oxide-loaded biochar composite material, characterized in that: The following steps are involved: The fungus residue powder is soaked in a mixed acid solution, and then rinsed, dried, and calcined to obtain biochar; dissolving yttrium salt and iron salt in water to obtain a mixed salt solution; dropping the mixed salt solution into boiling water and boiling the water to obtain a sol; adding an alkaline solution to the sol to produce precipitation and stirring, then adding the biochar, mixing, filtering, rinsing, and drying to obtain a solid; calcining the solid to obtain the yttrium iron oxide-loaded biochar composite material; The fungus residue powder is prepared by drying, crushing and grinding the oxytetracycline fungus residue.

2. The preparation method according to claim 1, characterized in that The mixed acid solution is a mixed solution of HF and HCl; the mass fraction of HF in the mixed acid solution is 0.9% to 2.2%, and the mass fraction of HCl is 1.48% to 1.55%; and the soaking time is 2 hours.

3. The preparation method according to claim 1, characterized in that When preparing biochar, the calcination temperature is 400° C. and the calcination time is 3 h.

4. The preparation method according to claim 1, characterized in that The yttrium salt is Y(NO3)3·6H2O; the iron salt is Fe(NO3)3·9H2O; the concentration of the yttrium salt in the mixed salt solution is 0.15 mol / L; and the molar ratio of the yttrium salt to the iron salt is 1:

1.

5. The preparation method according to claim 1, characterized in that The boiling time is 15 minutes; the alkaline solution is a K2CO3 solution with a mass concentration of 5%; the amount of the alkaline solution added is sufficient to turn the phenolphthalein test paper red.

6. The preparation method according to claim 1, characterized in that The added amount of the biochar is 0.25 to 2 times the mass of yttrium ferrite generated by the yttrium salt and the iron salt.

7. The preparation method according to claim 1, characterized in that When the solid is calcined, the calcination conditions are: calcination at 700° C. for 3 hours under an inert atmosphere.

8. The yttrium iron oxide-loaded biochar composite material prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the yttrium iron oxide-loaded biochar composite material as claimed in claim 8 in adsorbing chlortetracycline in wastewater.

10. The use according to claim 9, characterized in that The yttrium iron oxide-loaded biochar composite material according to claim 8 is added to the wastewater; the addition amount of the yttrium iron oxide-loaded biochar composite material in the wastewater is 0.05 g / L; the concentration of chlortetracycline in the wastewater is 10 to 200 mg / L.

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