阅读说明：本技术 一种核壳结构γ-Al2O3的制备方法及其应用 (Gamma-Al with core-shell structure2O3Preparation method and application thereof ) 是由 蔡卫权 罗锦璐 党成雄 彭锦豪 于 2021-08-06 设计创作，主要内容包括：本发明涉及一种核壳结构γ-Al-(2)O-(3)的制备方法及其应用。所述方法包括：称取碳源、甘氨酸、铝盐和沉淀剂,溶于水中,将所得溶液进行水热反应,反应冷却后取出的产物经分离、洗涤、干燥和研磨后,在空气氛围下焙烧。本发明以特定的五碳糖为碳源,经一步水热反应后,碳球的外表面与内核同时沉淀出薄水铝石铝,焙烧除去碳球后,形成一种独特核壳结构的γ-Al-(2)O-(3)粒子。该材料不仅具有颗粒尺寸均匀、比表面积较高的优点,而且能够处理高浓度的有机砷废水。处理对氨基苯胂酸(p-ASA)废水时,吸附量可达101.74mg/g。此外,本发明引入碳模板剂绿色环保,成本低,为解决常规材料处理有机砷废水吸附量低的难题提供一种方案。(The invention relates to a gamma-Al core-shell structure 2 O 3 The preparation method and the application thereof. The method comprises the following steps: weighing a carbon source, glycine, aluminum salt and a precipitator, dissolving the carbon source, glycine, aluminum salt and precipitator in water, carrying out hydrothermal reaction on the obtained solution, separating, washing, drying and grinding a product taken out after the reaction is cooled, and roasting the product in an air atmosphere. The invention takes specific pentose as a carbon source, and the outer surface and the inner core of the carbon sphere are simultaneously precipitated after one-step hydrothermal reactionThe boehmite aluminum is taken out and roasted to remove the carbon spheres to form the gamma-Al with a unique core-shell structure 2 O 3 Particles. The material not only has the advantages of uniform particle size and higher specific surface area, but also can treat high-concentration organic arsenic wastewater. When the p-amino phenylarsonic acid (p-ASA) wastewater is treated, the adsorption capacity can reach 101.74 mg/g. In addition, the carbon template agent is introduced, so that the method is environment-friendly and low in cost, and a scheme is provided for solving the problem of low adsorption capacity of the conventional material in the treatment of the organic arsenic wastewater.)

1. Gamma-Al with core-shell structure₂O₃The preparation method is characterized by comprising the following steps:

dissolving a carbon source, glycine, aluminum salt and a precipitator in water, carrying out hydrothermal reaction on the obtained solution, separating, washing, drying and grinding a product taken out after cooling the reaction, and roasting the product in an air atmosphere to finally obtain the gamma-Al with the core-shell structure₂O₃Particles.

2. The core-shell structure γ -Al of claim 1₂O₃The preparation method is characterized in that the aluminum salt accounts for 1 part by mass, the carbon source accounts for 3-5 parts by mass, the glycine accounts for 0.5-0.7 part by mass, and the precipitant accounts for 1-3 parts by volume; 50 parts by volume of water.

3. The core-shell structure γ -Al of claim 1₂O₃The method of (2) is characterized in that the carbon source is any one or two or more of xylose, ribose and arabinose, the aluminum salt is aluminum nitrate,the precipitant is formamide.

4. The core-shell structure γ -Al of claim 1₂O₃The preparation method is characterized in that the time of the hydrothermal reaction is 18-30h, and the temperature of the hydrothermal reaction is 170-190 ℃.

5. The core-shell structure γ -Al of claim 1₂O₃The preparation method is characterized in that the roasting temperature is 600 ℃, and the roasting time is 2 hours.

6. Gamma-Al with core-shell structure prepared by the method of any one of claims 1 to 5₂O₃。

7. The core-shell structure γ -Al of claim 6₂O₃The method is characterized in that the diameter of the inner core is 0.8-1.6 μm, and the thickness of the shell layer is 0.2-0.4 μm.

8. The core-shell structure of claim 7 γ -Al₂O₃Characterized in that the core-shell structure is gamma-Al₂O₃Is applied to the treatment of organic arsenic wastewater.

9. The core-shell structure γ -Al of claim 8₂O₃The method is characterized in that the organic arsenic wastewater is wastewater containing p-amino phenylarsonic acid.

10. Core-shell structure γ -Al according to claim 9₂O₃The application of (2) is characterized in that the initial concentration of the p-amino phenylarsonic acid in the organic arsenic wastewater is 0.5-200mg/L, and the initial pH of the solution is 3.8-6.5.

Technical Field

The invention belongs to the field of environmental pollution treatment, and particularly relates to a gamma-Al core-shell structure₂O₃The preparation method and the application thereof.

Background

Organic arsenic compounds are widely used in poultry feed to control poultry intestinal parasites and improve feed efficiency. Among them, p-amino phenylarsonic acid (p-ASA) is one of the most representative additives. p-ASA is scarcely retained in the body of poultry and is totally excreted from urine and feces. When animal excrement is used as a fertilizer, a large amount of arsenic-containing compounds is introduced into agricultural soil. The p-ASA structurally contains arsenic acid groups which can be degraded and gradually converted into highly toxic inorganic arsenic through biological and non-biological processes, thus threatening the ecological environment and human health. Therefore, the removal of organic arsenic before its conversion to inorganic arsenic is critical for environmental protection.

Metal oxides, hydroxides and clay minerals are important constituents of soils and sediments and are widely used for their ability to adsorb arsenic in various forms. For example, patent application publication No. CN111333168A discloses that ferrous salt and persulfate are added into arsenic-containing water to generate iron oxyhydroxide adsorbent, so as to achieve the purpose of synchronous oxidative degradation and in-situ adsorption for removing organic arsenic in water, and the concentration of organic arsenic in the stock solution before treatment is 0.1-100 μ M, which is a trace adsorption process. Patent application publication No. CN106277278A discloses that by adding iron oxide and a hydrogen peroxide oxidizing agent, arsenic compounds are converted from organic arsenic to inorganic arsenic in the state of an arsenic compound, while the released inorganic arsenic is effectively adsorbed in the form of Fe — As chemical coordination bonds. Chen et Al developed commercial alpha-FeOOH and gamma-Al₂O₃Adsorption studies on p-ASA, commercial γ -Al, at an initial concentration of organic arsenic of 50M and pH 5₂O₃The equilibrium time for adsorbing organic arsenic is 48h, and the equilibrium adsorption rate reaches 90 percent (Wan-Ru Ch)en,Ching-Hua Huang.Surface adsorption of organoarsenic roxarsone and arsanilic acid on iron and aluminum oxides[J]Journal of Hazardous Materials,2012, 227-. However, most of the adsorbents are adsorbed in trace amounts, and secondary pollution can be caused in the treatment process. Based on this, a green and environment-friendly adsorbing material with high adsorption efficiency is urgently needed to be found to solve the problem of organic arsenic pollution.

The template method is one of the common methods for synthesizing some materials with specific morphology. When the material is synthesized, mesoporous zeolite, protein, surfactant and the like are often required to be added as templates. Spherical is a common morphology, as is common for carbon spheres. Sun et al used glucose as carbon source to synthesize monodisperse carbon spheres (divergent Sun, yang Li. colloidal carbon spheres and the core/shell structures with non-metallic nanoparticles [ J ] under hydrothermal conditions of 160-]Angewandte Chemie,2004,116(5), 607-. Compared with other templates, the carbon spheres prepared by the method have the advantages of relatively uniform particle size, green and environment-friendly synthesis process, simplicity in operation and the like. However, most of the materials synthesized by using carbon spheres as templates reported in the literature are hollow sphere structures, for example, Jia et al use carbon spheres as templates, urea as precipitant, lutetium ions are attached to the surfaces of the carbon spheres in the form of precipitates, and the materials are baked to obtain hollow sphere structures of metal oxides (blank Jia, cuimia Zhang, living Wang, et al preparation and luminescence properties of metal oxide spheres by a template-direct route [ J]Journal of Alloys and Compounds,2011,509(22), 6418-. The patent application with publication number CN112156783A discloses Ni-CaO-Ca₁₂Al₁₄O₃₃A preparation method and application of a bifunctional catalyst relate to a preparation process of intermediate product boehmite coated carbon sphere powder: (1) adding at least one of monosaccharide/disaccharide/polysaccharide, at least one of aluminum sulfate/aluminum nitrate/aluminum chloride, at least one of glycine and ammonia water/sodium hydroxide/formamide and the like as a precipitant into water at room temperature, carrying out hydrothermal reaction at 100-200 ℃ for 2-14h, cooling to room temperature after the reaction is finished, and then washing and drying to obtain boehmite coated carbon sphere particles. The shell is boehmite, the inner core is carbon ball, after bakingThe carbon spheres are burnt out, and the obtained product is of a hollow sphere structure.

Hitherto, the metal (hydro) oxide synthesized by using carbon spheres as a template is mainly spherical hollow structure, and less metal (hydro) oxide with a core-shell structure is prepared by using carbon spheres as a template and is used for adsorbing and separating organic arsenic pollutants. Compared with a hollow spherical structure, the core-shell structure may have a larger specific surface, more pore structures and surface groups, so that a larger space is provided for improving the adsorption performance of the material.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides the gamma-Al with the core-shell structure₂O₃The preparation method of the organic arsenic-containing composite material improves the material performance from the material, and is applied to the treatment of organic arsenic wastewater to achieve the aim of treating environmental pollution.

The purpose of the invention is realized by the following technical scheme:

Gamma-Al with core-shell structure₂O₃The preparation method comprises the following steps:

dissolving a carbon source, glycine, aluminum salt and a precipitator in water, carrying out hydrothermal reaction on the obtained solution, separating, washing, drying and grinding a product taken out after cooling the reaction, and roasting the product in an air atmosphere to finally obtain the gamma-Al with the core-shell structure₂O₃Particles.

Preferably, the aluminum salt accounts for 1 part by mass, the carbon source accounts for 3-5 parts by mass, the glycine accounts for 0.5-0.7 part by mass, and the precipitator accounts for 1-3 parts by volume; 50 parts by volume of water. In the invention, 1 part by mass: 1 part by volume is 1 g/mL.

Preferably, the carbon source is one or more of xylose, ribose and arabinose, the aluminum salt is aluminum nitrate, and the precipitant is formamide.

Preferably, the hydrothermal reaction time is 18-30 h.

Preferably, the hydrothermal reaction temperature is 170-.

Preferably, the roasting temperature is 600 ℃, and the roasting time is 2 hours.

Preference is given toThe core-shell structure of gamma-Al₂O₃Is applied to the treatment of organic arsenic wastewater.

The gamma-Al with the core-shell structure prepared by the method of the invention₂O₃The diameter of the core is 0.8-1.6 μm, and the thickness of the shell is about 0.2-0.4 μm.

The method specifically comprises the following steps of preparing the core-shell structure gamma-Al₂O₃Adding into organic arsenic waste water, reacting while stirring until the reaction reaches equilibrium adsorption.

Preferably, the organic arsenic wastewater is wastewater containing p-amino phenylarsonic acid.

Preferably, the initial concentration of p-amino phenylarsonic acid in the organic arsenic wastewater is 0.5-200mg/L, and the initial pH of the solution is 3.8-6.5.

The core-shell structure gamma-Al₂O₃The adsorption equilibrium time for adsorbing the waste water containing the p-amino phenylarsonic acid is 20-360min, and the adsorption quantity is 0.5-101.74 mg/g.

Compared with the prior art, the invention has the following main outstanding effects:

(1) taking specific pentose such as xylose, ribose or arabinose as a carbon source, precipitating boehmite aluminum on the outer surface of the carbon spheres and the inner core simultaneously after one-step hydrothermal reaction, removing the carbon spheres after roasting, and forming the gamma-Al with the core-shell structure₂O₃The particle has a core diameter of 0.8 to 1.6 μm, a shell thickness of about 0.2 to 0.4 μm, and a specific surface area of about 200m²(ii) in terms of/g. Compared with the hollow oxide particles obtained by air roasting by the traditional carbon template method, the core-shell structure is more unique.

(2) Core-shell structure gamma-Al prepared by carbon template method₂O₃Has specific and more excellent adsorption performance on organic arsenic and is suitable for removing high-concentration organic arsenic wastewater.

(3) Core-shell gamma-Al₂O₃When the p-amino phenylarsonic acid (p-ASA) in the wastewater is adsorbed and treated at normal temperature, the adsorption capacity can reach 101.74 mg/g.

Drawings

FIG. 1 is an XRD spectrum of samples prepared in examples 1 to 3 and comparative examples 1 to 3.

From FIG. 1It is seen that the XRD patterns of the 3 samples of the example and the 3 samples of the comparative example both conform to γ -Al₂O₃The diffraction peak of (1).

FIG. 2 is a TEM image of X-1 prepared in example 1.

As shown in FIG. 2, the diameter of the core of X-1 is about 1 to 1.2 μm, and the thickness of the shell is 0.2 to 0.3. mu.m.

FIG. 3 is a TEM image of R-1 prepared in example 2.

As can be seen from FIG. 3, the diameter of the core of R-1 is about 1 to 1.6 μm, and the thickness of the shell is 0.2 to 0.4. mu.m.

FIG. 4 is a TEM image of A-1 prepared in example 3.

As can be seen from FIG. 4, the diameter of the core of A-1 is about 0.8 to 1.2 μm, and the thickness of the shell is 0.2 to 0.4. mu.m.

FIG. 5 is a TEM image of Al-1 prepared in comparative example 1.

FIG. 6 is a TEM image of Al-2 prepared in comparative example 2.

FIG. 7 is a TEM image of Al-3 prepared in comparative example 3.

It can be seen from fig. 5-7 that the morphologies of the 3 samples prepared by the comparative examples were all irregular sheet-like structures.

FIG. 8 is a graph showing the adsorption kinetics of X-1 and Al-1 on phenylarsonic acid, which are prepared in example 1 and comparative example 1.

FIG. 9 is a graph showing the adsorption kinetics of R-1 and Al-2 on phenylarsonic acid, which are prepared in example 2 and comparative example 2.

FIG. 10 is a graph showing the adsorption kinetics of A-1 and Al-3 on phenylarsonic acid, prepared in example 3 and comparative example 3.

FIG. 11 is a graph showing the adsorption kinetics of X-1 and Al-1 on phenylarsonic acid, which are prepared in example 1 and comparative example 1.

FIG. 12 is a graph showing the adsorption kinetics of R-1 and Al-2 on phenylarsonic acid, which are prepared in example 2 and comparative example 2.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the embodiments of the present invention are not limited thereto.

Example 1

Weighing 3.2g of xylose, 0.48g of glycine, 0.8g of aluminum nitrate and 1.6mL of formamide, dissolving in 40mL of deionized water, transferring the obtained solution to a reaction kettle containing a polytetrafluoroethylene lining, carrying out hydrothermal reaction for 24h at 180 ℃, taking out a product after the reaction kettle is cooled, washing, drying and grinding the product, roasting the product for 2h at 600 ℃ in the air atmosphere, and finally obtaining the gamma-Al with the core-shell structure₂O₃Particles, denoted X-1.

Example 2

Weighing 2.4g of ribose, 0.4g of glycine, 0.8g of aluminum nitrate and 0.8mL of formamide, and dissolving in 40mL of deionized water; transferring the obtained solution into a reaction kettle containing a polytetrafluoroethylene lining, carrying out hydrothermal reaction for 18h at 190 ℃, taking out a product after cooling the reaction, washing, drying and grinding the product, and roasting the product for 2h at 600 ℃ in the air atmosphere to finally obtain the gamma-Al with the core-shell structure₂O₃Particles, denoted as R-1.

Example 3

Weighing 4g of arabinose, 0.56g of glycine, 0.8g of aluminum nitrate and 2.4mL of formamide, and dissolving in 40mL of deionized water; transferring the obtained solution into a reaction kettle containing a polytetrafluoroethylene lining, carrying out hydrothermal reaction for 30h at 170 ℃, taking out a product after cooling the reaction, washing, drying and grinding the product, and roasting the product for 2h at 600 ℃ in the air atmosphere to finally obtain the gamma-Al with the core-shell structure₂O₃Particles, denoted A-1.

Comparative example 1

Dissolving 0.8g of aluminum nitrate and 1.6mL of formamide in deionized water, transferring the obtained solution to a reaction kettle with a polytetrafluoroethylene lining, carrying out hydrothermal reaction for 24h at 180 ℃, taking out a product after the reaction is cooled, washing, drying and grinding the product, roasting the product for 2h at 600 ℃ in the air atmosphere, and finally obtaining a product gamma-Al₂O₃Is marked as Al-1.

Comparative example 2

0.8g of aluminum nitrate and 0.8mL of formamide were dissolved in 40mL of deionized water, and the resulting solution was transferred to a polytetrafluoroethylene-lined reaction vessel and subjected to hydrothermal reaction at 190 ℃ for 18 hours. After the reaction is cooled, the product taken out is washed, dried and ground, and is roasted for 2 hours at the temperature of 600 ℃ in the air atmosphere, and finally the product gamma is obtained-Al₂O₃Is marked as Al-2.

Comparative example 3

0.8g of aluminum nitrate and 2.4mL of formamide are dissolved in 40mL of deionized water; transferring the obtained solution into a polytetrafluoroethylene reaction kettle, and carrying out hydrothermal reaction for 30h at 170 ℃. After the reaction is cooled, the product taken out is washed, dried and ground, and is roasted for 2 hours at the temperature of 600 ℃ in the air atmosphere, and finally the product gamma-Al is obtained₂O₃Is marked as Al-3.

Experiment of adsorbent for adsorbing organic arsenic:

1. 0.05g of each of the samples (X-1, R-1, A-1, Al-2, and Al-3) prepared in examples 1 to 3 and comparative examples 1 to 3 was put into a beaker containing 50mL of a p-aminobenzarsonic acid solution at an initial concentration of 200mg/L, pH ═ 3.8, and the beaker was stirred in a magnetic stirrer.

The experimental results are as follows: as shown in FIG. 8, the adsorption of sample X-1 was in equilibrium at 360min, the equilibrium adsorption amount was 101.74mg/g, the adsorption of control sample Al-1 was in equilibrium at 120min, the equilibrium adsorption amount was 48.78mg/g, and the equilibrium adsorption amount of sample X-1 was 2.09 times that of control sample Al-1.

As shown in FIG. 9, the adsorption of sample R-1 reaches equilibrium at 360min, and the equilibrium adsorption amount is 99.65 mg/g; the control sample Al-2 reaches the adsorption equilibrium in 180min, the equilibrium adsorption capacity is 42.51mg/g, and the equilibrium adsorption capacity of the sample R-1 is 2.34 times of that of the control sample Al-2.

As shown in FIG. 10, the adsorption of sample A-1 was in equilibrium at 360min, the equilibrium adsorption amount was 96.83mg/g, the adsorption of control sample Al-3 was in equilibrium at 360min, the equilibrium adsorption amount was 47.86mg/g, and the equilibrium adsorption amount of sample A-1 was 2.02 times that of control sample Al-3.

2. 0.05g of each of the samples (X-1, Al-1) prepared in example 1 and comparative example 1 was put into a beaker containing 50mL of a p-amino phenylarsonic acid solution having an initial concentration of 100mg/L, pH ═ 4, and the beaker was stirred in a magnetic stirrer.

The experimental result is shown in FIG. 11, the adsorption of sample X-1 reaches equilibrium at 360min, and the equilibrium adsorption capacity is 81.12 mg/g; the control sample Al-1 reaches the adsorption equilibrium in 360min, the equilibrium adsorption capacity is 42.60mg/g, and the equilibrium adsorption capacity of the sample X-1 is 1.9 times of that of the control sample Al-1.

3. 0.1g of each of the samples (R-1 and Al-2) prepared in example 2 and comparative example 2 was put into a beaker containing 100mL of a p-aminobenzoic arsonic acid solution with an initial concentration of 0.5mg/L, pH ═ 6.5, and the beaker was placed in a magnetic stirrer and stirred.

The experimental result is shown in FIG. 12, the sample R-1 reaches the adsorption equilibrium at 20min, and the equilibrium adsorption amount is 0.5 mg/g; the control sample Al-2 reaches the adsorption equilibrium at 20min, the equilibrium adsorption quantity is 0.325mg/g, and the equilibrium adsorption quantity of the sample R-1 is 1.53 times of that of the control sample Al-2.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.