Layered bimetallic oxide surface modified waste pollen biomass as well as preparation method and application thereof
By constructing the lanthanum-based layered bimetal oxide composite in situ on waste pollen biomass, a high-efficiency adsorbent was prepared, which solved the problems of low adsorption amount and slow rate of existing adsorbents when removing water phosphate, and achieved resource utilization and efficient adsorption effects.
Patent Information
- Application Number
- CN202510500437.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-21
- Publication Date
- 2025-09-05
AI Technical Summary
When removing phosphate contaminants in water, existing adsorbents have low adsorption amount, high cost, slow adsorption rate and easy agglomeration, which limits their application.
Use waste pollen biomass as the precursor to construct a lanthanum-based layered bimetal oxide composite in situ to prepare waste pollen biomass adsorbent modified with layered bimetal oxide surface, and use the high affinity of lanthanum to improve adsorption performance.
It improves the specific surface area and adsorption efficiency of adsorbents, improves the adsorption and removal effect of phosphate in water, and realizes the resource utilization of waste, which is in line with the concept of green and low-carbon development.
Smart Images
Figure CN120586818A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of chemical separation, relates to an adsorbent, and specifically relates to a waste pollen biomass surface-modified with a layered bimetallic oxide, a preparation method thereof, and a method for adsorbing and removing phosphate substances in water. Background Art
[0002] At present, the problem of eutrophication of water bodies is becoming increasingly serious around the world, among which excessive phosphorus content is one of the main causes of eutrophication of water bodies. About 80% of phosphorus in nature is discharged with sewage after use. Studies have shown that eutrophication of water bodies can be controlled by reducing the input of phosphorus. In order to cope with the severe challenges that eutrophication of water bodies brings to human life and the natural environment, the development of economical and efficient means to remove phosphate pollutants in water bodies has important scientific research value and practical application significance. At present, the methods for removing phosphate from water bodies include precipitation, biological methods, adsorption methods, etc. Among them, the adsorption method has been widely studied due to its advantages such as simple operation, low cost and strong flexibility. However, the adsorption capacity of the phosphorus removal adsorbents currently reported is relatively low, and there are disadvantages such as high cost, slow adsorption rate and easy agglomeration of adsorbents, which limit their further application.
[0003] In contrast, metal composite materials offer advantages such as strong adsorption capacity and low cost. Modifying adsorbents with metal elements is an effective method for improving phosphorus removal. Layered double hydroxides have attracted widespread attention in the field of adsorption-based phosphorus removal. Commonly used modified metals include lanthanum, zirconium, and iron. Lanthanum metal has an excellent affinity for phosphates. Lanthanum is highly abundant, ranking second among rare earth elements, and has abundant reserves. Lanthanum-based composites also have the advantages of good acid resistance, environmental non-toxicity, and renewability, and perform well in the field of water pollutant removal.
[0004] Biochar is a by-product of the biomass pyrolysis process. It has the characteristics of a wide range of sources, rich pores, low cost, and environmental friendliness. It has significant advantages in removing organic pollutants (dyes, antibiotics) and inorganic pollutants (heavy metal ions, phosphates, and nitrates). Pure biochar generally has poor adsorption capacity for phosphates. Because the surface of pure biochar is usually negatively charged, it has a strong electrostatic repulsion with negatively charged anionic pollutants, thereby inhibiting the adsorption of phosphate ions. Metal ions have a high affinity for phosphate ions, so modifying the surface of biochar with metals can effectively improve the adsorption capacity of biochar. At the same time, using waste biomass resources to prepare phosphorus removal adsorbents can realize the resource utilization of waste and reduce the environmental burden.
[0005] Based on these characteristics, this study uses waste pollen (PL) as a biochar precursor, in situ constructing a lanthanum-based layered double hydroxide composite material on its surface, resulting in a waste pollen biomass modified with layered double hydroxides. This method is simple, effective, and highly efficient in phosphorus removal, providing a new approach for developing low-cost modified adsorbent materials. Summary of the Invention
[0006] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to disclose a method for preparing waste pollen biomass surface-modified with layered bimetallic oxides.
[0007] Technical Solution
[0008] A method for preparing waste pollen biomass surface-modified with layered bimetallic oxides comprises: adding soluble magnesium salt and lanthanum salt to deionized water and ultrasonically dispersing them uniformly, adding hexamethylenetetramine and ultrasonically dispersing them uniformly, then adding PL@Al2O3, transferring the mixed solution to a reactor, reacting at 80-160°C for 8-36 hours, preferably at 120°C for 10 hours, cooling the reactor to room temperature, centrifuging, washing with deionized water until the supernatant is neutral, collecting a powdered product, and drying it to obtain waste pollen biomass surface-modified with layered bimetallic oxides (PL@Mg / La-LDH).
[0009] The soluble magnesium salt of the present invention is magnesium nitrate, magnesium chloride or magnesium sulfate, preferably magnesium nitrate.
[0010] The soluble lanthanum salt of the present invention is lanthanum chloride or lanthanum nitrate, preferably lanthanum nitrate.
[0011] In a preferred embodiment of the present invention, the material ratios of deionized water, soluble magnesium salt, soluble lanthanum salt, hexamethylenetetramine, and PL@Al2O3 participating in the reaction are 25mL: 0.5~32mmol: 0.5~4mmol: 0.187~5.6g: 0.02~0.5g, preferably 25mL: 12mmol: 2mmol: 1.12g: 0.1g.
[0012] In a preferred embodiment of the present invention, the preparation method of the PL@Al2O3 comprises the following steps:
[0013] a) Pollen pretreatment: Grind the waste pollen into a fine powder and soak it in ethanol for 1 to 7 days, preferably 4 days, and then dry it. During this period, filter it every day to remove oil and fat substances in the pollen. In particular, soak 1 to 15 g of powdered pollen in 250 mL of ethanol, preferably soak 8 g of powdered pollen in 250 mL of ethanol solution;
[0014] b) preparing an aqueous solution of a soluble aluminum salt, adding the pretreated pollen to the solution and soaking for 4 to 24 hours, preferably 12 hours, to allow aluminum ions to be adsorbed, centrifuging, and fully drying. The solution is then calcined at 200 to 600°C for 0.5 to 4 hours, preferably 300°C for 1 hour. After cooling to room temperature, an aluminum oxide layer is formed on the surface of the pollen to stabilize the pollen morphology. The treated pollen is set aside and designated as PL@Al2O3. The solid-to-liquid ratio of deionized water, soluble aluminum salt, and pretreated pollen is 250 mL: 0.0625 to 0.5 mol: 2 to 10 g, preferably 250 mL: 0.125 mol: 5 g.
[0015] In a preferred embodiment of the present invention, the soluble aluminum salt in step b) is aluminum chloride, aluminum sulfate or aluminum nitrate, preferably aluminum nitrate.
[0016] The second object of the present invention is to use the waste pollen biomass surface-modified with layered bimetallic oxides prepared by the method of the present invention for the adsorption and removal of phosphates in water.
[0017] The application experiments are as follows:
[0018] In an environment of 35°C, 10 mg of the prepared layered bimetallic oxide surface-modified waste pollen biomass material was added to every 10 mL of 0.1 g / L KH2PO4 solution. The pH of the solution was adjusted to 3-12. After the adsorption reaction for 0.5-24 h, the phosphate in the solution was adsorbed / enriched on the material surface; and the reacted material was separated.
[0019] The adsorption amount Q (mg / g) was calculated according to formula (1):
[0020] (1)
[0021] Where: C0 and C (mg / L) are the initial concentration and equilibrium concentration of the phosphate solution, respectively, V (L) is the volume of the adsorption solution, and m (g) is the mass of the adsorbent material.
[0022] The characteristics of the present invention are:
[0023] (1) Using waste biomass as a precursor, the adsorbent was designed by loading lanthanum-based complexes on the surface after surface chemical modification, which achieved the construction of a surface hierarchical structure and helped to increase the specific surface area of the adsorbent material;
[0024] (2) Using common environmental waste as biomass resources to develop modified adsorbents can overcome the shortcomings of pure biochar’s poor adsorption effect, thereby improving the adsorption and removal of phosphates in water bodies;
[0025] (3) The development of agricultural waste resources provides an important reference for the resource utilization of environmental waste and the effective management of agricultural solid waste. It is in line with the concept of green and low-carbon development and provides new ideas for the research of chemical adsorption phosphorus removal.
[0026] Beneficial effects
[0027] This invention uses waste biomass as a precursor and, through in-situ surface modification, produces a novel adsorbent with a hierarchical structure. This not only overcomes the poor adsorption efficiency of pure biomass but also increases the specific surface area of the adsorbent material, thereby improving the adsorption and removal of phosphates from water. This invention has promising applications in the enrichment, separation, and removal of common phosphate pollutants from water. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 SEM of pure pollen biomass;
[0029] Figure 2 SEM image of waste pollen biomass surface modified with layered bimetallic oxides.
[0030] Figure 3 . pH optimization for phosphate adsorption removal by waste pollen biomass modified with layered bimetallic oxide surfaces. DETAILED DESCRIPTION
[0031] The present invention will be described in detail below with reference to the following examples so that those skilled in the art can better understand the present invention. However, the present invention is not limited to the following examples.
[0032] Unless otherwise defined, the terms used herein (including technical and scientific terms) should be interpreted as having the same meaning as commonly understood by those skilled in the art to which the present invention belongs. It will also be understood that the terms used herein should be interpreted as having the meaning consistent with their meaning in the context of this specification and the related art, and should not be interpreted in an idealized or excessive manner unless specifically defined as such herein.
[0033] Example 1
[0034] A method for preparing waste pollen biomass surface-modified with layered bimetallic oxides comprises the following steps:
[0035] a) Pollen pretreatment: First, the waste pollen was ground into a fine powder. 1 g of the powdered pollen was soaked in 250 mL of ethanol for 1 day, during which time the pollen was filtered daily to remove oily substances.
[0036] b) After drying the treated pollen, dissolve 23.45 g of aluminum nitrate nonahydrate in 250 mL of deionized water, stir thoroughly, and then add 2 g of the pretreated pollen and soak for 4 hours to absorb aluminum ions.
[0037] c) The sample after aluminum ion adsorption was centrifuged at 8000 rpm for 10 minutes. After being fully dried, the sample was calcined and pyrolyzed at 200°C for 0.5 hours. After cooling to room temperature, an aluminum oxide layer was formed on the surface of the pollen to stabilize the pollen morphology. The treated pollen was set aside and named PL@Al2O3.
[0038] d) Waste pollen biomass surface-modified with layered bimetallic oxides: 0.5 mmol of magnesium nitrate hexahydrate and 0.5 mmol of lanthanum nitrate hexahydrate were added to 25 mL of deionized water. After ultrasonic dispersion for 0.5 h, 0.187 g of hexamethylenetetramine was added. Ultrasonic dispersion was continued for 10 min, followed by 0.02 g of PL@Al2O3. The solution was then transferred to a reactor and reacted at 80°C for 8 h. After cooling the reactor to room temperature, the reactants were centrifuged at 8000 rpm for 5 min and washed with deionized water until the supernatant was neutral. The powdered product was then collected and dried to obtain layered bimetallic oxide-surface-modified waste pollen biomass (PL@Mg / La-LDH).
[0039] The application experiments are as follows:
[0040] In an environment of 35°C, 10 mg of the prepared layered bimetallic oxide surface-modified waste pollen biomass material was added to every 10 mL of 0.1 g / L KH2PO4 solution. The pH of the solution was adjusted to 3. After the adsorption reaction lasted for 0.5 h, the phosphate in the solution was adsorbed / enriched on the surface of the material, and the reacted material was separated.
[0041] The adsorption capacity of phosphate on the prepared layered bimetallic oxide surface-modified waste pollen biomass was 6.23 mg / g.
[0042] Example 2
[0043] A method for preparing waste pollen biomass surface-modified with layered bimetallic oxides comprises the following steps:
[0044] a) Pollen pretreatment: First, the waste pollen was ground into a fine powder. 5 g of the powdered pollen was soaked in 250 mL of ethanol solution for 2 days, during which time the pollen was filtered daily to remove oily substances.
[0045] b) After drying the treated pollen, dissolve 70.35 g of aluminum nitrate nonahydrate in 250 mL of deionized water, stir thoroughly, and then add 4 g of the pretreated pollen and soak for 10 hours to adsorb aluminum ions.
[0046] c) The sample after aluminum ion adsorption was centrifuged at 8000 rpm for 10 minutes. After being fully dried, the sample was calcined and pyrolyzed at 500°C for 2 hours. After cooling to room temperature, an aluminum oxide layer was formed on the surface of the pollen to stabilize the pollen morphology. The treated pollen was set aside and named PL@Al2O3.
[0047] d) Layered bimetallic oxide surface-modified waste pollen biomass: 4 mmol of magnesium nitrate hexahydrate and 1 mmol of lanthanum nitrate hexahydrate were added to 25 mL of deionized water. After ultrasonic dispersion for 0.5 h, 0.374 g of hexamethylenetetramine was added. Ultrasonic dispersion was continued for 10 min, followed by 0.1 g of PL@Al2O3. The solution was then transferred to a reactor and reacted at 100°C for 24 h. After cooling the reactor to room temperature, the reactants were centrifuged at 8000 rpm for 5 min and washed with deionized water until the supernatant was neutral. The powdered product was collected and dried to obtain layered bimetallic oxide surface-modified waste pollen biomass (PL@Mg / La-LDH).
[0048] The application experiments are as follows:
[0049] In an environment of 35°C, 10 mg of the prepared layered bimetallic oxide surface-modified waste pollen biomass material was added to every 10 mL of 0.1 g / L KH2PO4 solution. The pH of the solution was adjusted to 6. After the adsorption reaction for 2 hours, the phosphate in the solution was adsorbed / enriched on the surface of the material; the reacted material was separated.
[0050] The adsorption capacity of phosphate on the prepared layered bimetallic oxide surface-modified waste pollen biomass was 13.56 mg / g.
[0051] Example 3
[0052] A method for preparing waste pollen biomass surface-modified with layered bimetallic oxides comprises the following steps:
[0053] a) Pollen pretreatment: First, the waste pollen was ground into a fine powder. 7.5 g of the powdered pollen was soaked in 250 mL of ethanol solution for 3 days, with daily filtration to remove oily substances in the pollen.
[0054] b) After drying the treated pollen, dissolve 93.8 g of aluminum nitrate nonahydrate in 250 mL of deionized water, stir thoroughly, and then add 5 g of the pretreated pollen and soak for 6 hours to absorb aluminum ions.
[0055] c) The sample after aluminum ion adsorption was centrifuged at 8000 rpm for 10 minutes. After being fully dried, the sample was calcined and pyrolyzed at 300°C for 4 hours. After cooling to room temperature, an aluminum oxide layer was formed on the surface of the pollen to stabilize the pollen morphology. The treated pollen was set aside and named PL@Al2O3.
[0056] d) Layered bimetallic oxide surface-modified waste pollen biomass: 6 mmol of magnesium nitrate hexahydrate and 2 mmol of lanthanum nitrate hexahydrate were added to 25 mL of deionized water. After ultrasonic dispersion for 0.5 h, 2.8 g of hexamethylenetetramine was added. Ultrasonic dispersion was continued for 10 min, followed by 0.15 g of PL@Al2O3. The solution was then transferred to a reactor and reacted at 120°C for 16 h. After cooling the reactor to room temperature, the reactants were centrifuged at 8000 rpm for 5 min and washed with deionized water until the supernatant was neutral. The powdered product was collected and dried to obtain layered bimetallic oxide surface-modified waste pollen biomass (PL@Mg / La-LDH).
[0057] The application experiments are as follows:
[0058] In an environment of 35°C, 10 mg of the prepared layered bimetallic oxide surface-modified waste pollen biomass material was added to every 10 mL of 0.1 g / L KH2PO4 solution. The pH of the solution was adjusted to 3. After the adsorption reaction for 5 hours, the phosphate in the solution was adsorbed / enriched on the surface of the material; the reacted material was separated.
[0059] The adsorption capacity of phosphate on the waste pollen biomass modified with the prepared layered bimetallic oxide surface was 25.5 mg / g.
[0060] Example 4
[0061] A method for preparing waste pollen biomass surface-modified with layered bimetallic oxides comprises the following steps:
[0062] a) Pollen pretreatment: First, the waste pollen was ground into a fine powder. 8 g of the powdered pollen was soaked in 250 mL of ethanol for 4 days, with daily filtration to remove oily substances in the pollen.
[0063] b) After drying the treated pollen, dissolve 46.89 g of aluminum nitrate nonahydrate in 250 mL of deionized water, stir thoroughly, and then add 5 g of pretreated pollen and soak for 12 hours to absorb aluminum ions.
[0064] c) The sample after aluminum ion adsorption was centrifuged at 8000 rpm for 10 minutes. After being fully dried, the sample was calcined and pyrolyzed at 300°C for 1 hour. After cooling to room temperature, an aluminum oxide layer was formed on the surface of the pollen to stabilize the pollen morphology. The treated pollen was set aside and named PL@Al2O3.
[0065] d) Layered bimetallic oxide surface-modified waste pollen biomass: 12 mmol of magnesium nitrate hexahydrate and 2 mmol of lanthanum nitrate hexahydrate were added to 25 mL of deionized water. After ultrasonic dispersion for 0.5 h, 1.12 g of hexamethylenetetramine was added. Ultrasonic dispersion was continued for 10 min, followed by 0.1 g of PL@Al2O3. The solution was then transferred to a reactor and reacted at 120°C for 10 h. After cooling the reactor to room temperature, the reactants were centrifuged at 8000 rpm for 5 min and washed with deionized water until the supernatant was neutral. The powdered product was collected and dried to obtain layered bimetallic oxide surface-modified waste pollen biomass (PL@Mg / La-LDH).
[0066] The application experiments are as follows:
[0067] In an environment of 35°C, 10 mg of the prepared layered bimetallic oxide surface-modified waste pollen biomass material was added to every 10 mL of 0.1 g / L KH2PO4 solution. The pH of the solution was adjusted to 3. After the adsorption reaction for 8 hours, the phosphate in the solution was adsorbed / enriched on the surface of the material; the reacted material was separated.
[0068] The adsorption capacity of phosphate on the waste pollen biomass modified with the prepared layered bimetallic oxide surface was 54.7 mg / g.
[0069] Based on this example, the morphology of the prepared layered bimetallic oxide surface-modified waste pollen biomass material was characterized. Figure 1 This is a SEM image of pure pollen biomass. It can be seen from the figure that the carbonized pollen after treatment is rugby-shaped with a radius of about 15μm and a relatively rough surface. Most of the concave pores in the network structure are filled with amorphous aluminum oxide. Figure 2 This is an SEM image of waste pollen biomass modified with layered bimetallic oxides. It can be seen that PL@Mg / La-LDH presents a spherical flower cluster with a diameter of about 20μm, and the LDH nanosheets clearly visible on the surface are staggered. Figure 3This is the pH optimization of the adsorption and removal of phosphate by waste pollen biomass modified with layered bimetallic oxides. It can be seen that the adsorption capacity of waste pollen biomass modified with layered bimetallic oxides is the largest at pH 3.
[0070] Example 5
[0071] A method for preparing waste pollen biomass surface-modified with layered bimetallic oxides comprises the following steps:
[0072] a) Pollen pretreatment: First, the waste pollen was ground into a fine powder. 15 g of the powdered pollen was soaked in 250 mL of ethanol solution for 7 days, with daily filtration to remove oily substances in the pollen.
[0073] b) After drying the treated pollen, dissolve 187.56 g of aluminum nitrate nonahydrate in 250 mL of deionized water, stir thoroughly, and then add 10 g of the pretreated pollen and soak for 24 hours to absorb aluminum ions.
[0074] c) The sample after aluminum ion adsorption was centrifuged at 8000 rpm for 10 minutes. After being fully dried, the sample was calcined and pyrolyzed at 600°C for 4 hours. After cooling to room temperature, an aluminum oxide layer was formed on the surface of the pollen to stabilize the pollen morphology. The treated pollen was set aside and named PL@Al2O3.
[0075] d) Layered bimetallic oxide surface-modified waste pollen biomass: 32 mmol of magnesium nitrate hexahydrate and 4 mmol of lanthanum nitrate hexahydrate were added to 25 mL of deionized water. After ultrasonic dispersion for 0.5 h, 5.6 g of hexamethylenetetramine was added. Ultrasonic dispersion was continued for 10 min, followed by 0.5 g of PL@Al2O3. The solution was then transferred to a reactor and reacted at 160°C for 36 h. After cooling the reactor to room temperature, the reactants were centrifuged at 8000 rpm for 5 min and washed with deionized water until the supernatant was neutral. The powdered product was collected and dried to obtain layered bimetallic oxide surface-modified waste pollen biomass (PL@Mg / La-LDH).
[0076] The application experiments are as follows:
[0077] In an environment of 35°C, 10 mg of the prepared layered bimetallic oxide surface-modified waste pollen biomass material was added to every 10 mL of 0.1 g / L KH2PO4 solution. The pH of the solution was adjusted to 12. After the adsorption reaction lasted for 24 hours, the phosphate in the solution was adsorbed / enriched on the surface of the material; the reacted material was separated.
[0078] The adsorption capacity of phosphate by the prepared layered bimetallic oxide surface-modified waste pollen biomass is 5.3 mg / g.
[0079] Example 6
[0080] A method for preparing waste pollen biomass surface-modified with layered bimetallic oxides comprises the following steps:
[0081] a) Pollen pretreatment: First, the waste pollen was ground into a fine powder. 8 g of the powdered pollen was soaked in 250 mL of ethanol solution for 4 days, during which time the pollen was filtered daily to remove oily substances.
[0082] b) After drying the treated pollen, dissolve 30.167 g of aluminum chloride hexahydrate in 250 mL of deionized water, stir thoroughly, and then add 5 g of pretreated pollen and soak for 12 hours to adsorb aluminum ions.
[0083] c) The sample after aluminum ion adsorption was centrifuged at 8000 rpm for 10 minutes. After being fully dried, the sample was calcined and pyrolyzed at 300°C for 1 hour. After cooling to room temperature, an aluminum oxide layer was formed on the surface of the pollen to stabilize the pollen morphology. The treated pollen was set aside and named PL@Al2O3.
[0084] d) Waste pollen biomass surface-modified with layered bimetallic oxides: 12 mmol of magnesium chloride and 2 mmol of lanthanum chloride were added to 25 mL of deionized water. After ultrasonic dispersion for 0.5 h, 1.12 g of hexamethylenetetramine was added. Ultrasonic dispersion was continued for 10 min, followed by 0.1 g of PL@Al2O3. The solution was then transferred to a reactor and reacted at 120°C for 10 h. After cooling the reactor to room temperature, the reactants were centrifuged at 8000 rpm for 5 min and washed with deionized water until the supernatant was neutral. The powdered product was then collected and dried to obtain layered bimetallic oxide-surface-modified waste pollen biomass (PL@Mg / La-LDH).
[0085] The application experiments are as follows:
[0086] In an environment of 35°C, 10 mg of the prepared layered bimetallic oxide surface-modified waste pollen biomass material was added to every 10 mL of 0.1 g / L KH2PO4 solution. The pH of the solution was adjusted to 3. After the adsorption reaction for 8 hours, the phosphate in the solution was adsorbed / enriched on the surface of the material; the reacted material was separated.
[0087] The adsorption capacity of phosphate on the waste pollen biomass modified with the prepared layered bimetallic oxide surface was 51.35 mg / g.
[0088] Example 7
[0089] A method for preparing waste pollen biomass surface-modified with layered bimetallic oxides comprises the following steps:
[0090] a) Pollen pretreatment: First, the waste pollen was ground into a fine powder. 8 g of the powdered pollen was soaked in 250 mL of ethanol solution for 4 days, during which time the pollen was filtered daily to remove oily substances.
[0091] b) After drying the treated pollen, dissolve 46.89 g of aluminum nitrate nonahydrate in 250 mL of deionized water, stir thoroughly, and then add 5 g of pretreated pollen and soak for 12 hours to absorb aluminum ions.
[0092] c) The sample after aluminum ion adsorption was centrifuged at 8000 rpm for 10 minutes. After being fully dried, the sample was calcined and pyrolyzed at 300°C for 1 hour. After cooling to room temperature, an aluminum oxide layer was formed on the surface of the pollen to stabilize the pollen morphology. The treated pollen was set aside and named PL@Al2O3.
[0093] d) Waste pollen biomass surface-modified with layered bimetallic oxides: 12 mmol of magnesium sulfate and 2 mmol of lanthanum nitrate hexahydrate were added to 25 mL of deionized water. After ultrasonic dispersion for 0.5 h, 1.12 g of hexamethylenetetramine was added. Ultrasonic dispersion was continued for 10 min, followed by 0.1 g of PL@Al2O3. The solution was then transferred to a reactor and reacted at 120°C for 10 h. After cooling the reactor to room temperature, the reactants were centrifuged at 8000 rpm for 5 min and washed with deionized water until the supernatant was neutral. The powdered product was collected and dried to obtain layered bimetallic oxide-surface-modified waste pollen biomass (PL@Mg / La-LDH).
[0094] The application experiments are as follows:
[0095] In an environment of 35°C, 10 mg of the prepared layered bimetallic oxide surface-modified waste pollen biomass material was added to every 10 mL of 0.1 g / L KH2PO4 solution. The pH of the solution was adjusted to 3. After the adsorption reaction for 8 hours, the phosphate in the solution was adsorbed / enriched on the surface of the material; the reacted material was separated.
[0096] The adsorption capacity of phosphate on the waste pollen biomass modified with the prepared layered bimetallic oxide surface was 50.98 mg / g.
[0097] Example 8
[0098] A method for preparing waste pollen biomass surface-modified with layered bimetallic oxides comprises the following steps:
[0099] a) Pollen pretreatment: First, the waste pollen was ground into a fine powder. 8 g of the powdered pollen was soaked in 250 mL of ethanol solution for 4 days, during which time the pollen was filtered daily to remove oily substances.
[0100] b) After drying the treated pollen, dissolve 42.77 g of aluminum sulfate in 250 mL of deionized water, stir thoroughly, and then add 5 g of pretreated pollen and soak for 12 hours to absorb aluminum ions.
[0101] c) The sample after aluminum ion adsorption was centrifuged at 8000 rpm for 10 minutes. After being fully dried, the sample was calcined and pyrolyzed at 300°C for 1 hour. After cooling to room temperature, an aluminum oxide layer was formed on the surface of the pollen to stabilize the pollen morphology. The treated pollen was set aside and named PL@Al2O3.
[0102] d) Layered bimetallic oxide surface-modified waste pollen biomass: 12 mmol of magnesium sulfate and 2 mmol of lanthanum chloride were added per 25 mL of deionized water. After ultrasonic dispersion for 0.5 h, 1.12 g of hexamethylenetetramine was added. Ultrasonic dispersion was continued for 10 min, followed by 0.1 g of PL@Al2O3. The solution was then transferred to a reactor and reacted at 120°C for 10 h. After cooling the reactor to room temperature, the reactants were centrifuged at 8000 rpm for 5 min and washed with deionized water until the supernatant was neutral. The powdered product was collected and dried to obtain layered bimetallic oxide surface-modified waste pollen biomass (PL@Mg / La-LDH).
[0103] The application experiments are as follows:
[0104] In an environment of 35°C, 10 mg of the prepared layered bimetallic oxide surface-modified waste pollen biomass material was added to every 10 mL of 0.1 g / L KH2PO4 solution. The pH of the solution was adjusted to 3. After the adsorption reaction for 8 hours, the phosphate in the solution was adsorbed / enriched on the surface of the material; the reacted material was separated.
[0105] The adsorption capacity of phosphate on the waste pollen biomass modified with the prepared layered bimetallic oxide surface was 49.33 mg / g.
[0106] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the description of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.
Claims
1. A method for preparing waste pollen biomass surface modified with layered bimetallic oxides, characterized in that: include: After adding soluble magnesium salt and lanthanum salt to deionized water and ultrasonically dispersing them uniformly, hexamethylenetetramine was added and ultrasonically dispersed uniformly, and then PL@Al2O3 was added. The mixed solution was transferred to a reactor and reacted at 80-160°C for 8-36 hours. After the reactor was cooled to room temperature, it was centrifuged and washed with deionized water until the supernatant was neutral. The powdered product was collected and dried to obtain PL@Mg / La-LDH, a waste pollen biomass surface modified with layered bimetallic oxides.
2. The method for preparing waste pollen biomass surface-modified with layered bimetallic oxides according to claim 1, characterized in that: After adding soluble magnesium salt and lanthanum salt to deionized water and ultrasonically dispersing them uniformly, hexamethylenetetramine was added and ultrasonically dispersed uniformly, and then PL@Al2O3 was added. The mixed solution was transferred to a reactor and reacted at 120°C for 10 hours. After the reactor was cooled to room temperature, it was centrifuged and washed with deionized water until the supernatant was neutral. The powdered product was collected and dried to obtain the product.
3. The method for preparing waste pollen biomass surface-modified with layered bimetallic oxides according to claim 1, characterized in that: The soluble magnesium salt is magnesium nitrate, magnesium chloride or magnesium sulfate.
4. The method for preparing waste pollen biomass surface-modified with layered bimetallic oxides according to claim 1, characterized in that: The soluble magnesium salt is magnesium nitrate.
5. The method for preparing waste pollen biomass surface-modified with layered bimetallic oxides according to claim 1, characterized in that: The soluble lanthanum salt is lanthanum chloride or lanthanum nitrate.
6. The method for preparing waste pollen biomass surface-modified with layered bimetallic oxides according to claim 1, characterized in that: The soluble lanthanum salt is lanthanum nitrate.
7. The method for preparing waste pollen biomass surface-modified with layered bimetallic oxides according to claim 1, characterized in that: The material ratio of deionized water, soluble magnesium salt, soluble lanthanum salt, hexamethylenetetramine, and PL@Al2O3 involved in the reaction is 25mL: 0.5~32mmol: 0.5~4mmol: 0.187~5.6g: 0.02~0.5g, preferably 25mL: 12mmol: 2mmol: 1.12g: 0.1g.
8. Waste pollen biomass surface-modified with layered bimetallic oxides prepared by the method according to any one of claims 1 to 7.
9. An application of waste pollen biomass surface-modified with a layered bimetallic oxide as claimed in claim 8, characterized in that: It is applied to the adsorption and removal of phosphate in water.