Preparation method of supported Fe / La-MOF bimetallic metal-organic framework adsorption precipitant for high-phosphorus wastewater, product and application

Abstract

The application relates to a preparation method, product and application of a supported Fe / La-MOF bimetallic metal organic framework adsorption precipitator for high-phosphorus wastewater. 3‑ The La / Fe bimetallic adsorption precipitator with large specific surface area and porosity is constructed by using the structural advantages of MOFs materials, PO4 in water is quickly captured by Fe and La, the rapid removal of phosphorus-containing wastewater is realized, high-efficiency solid loading of the supported Fe / La-MOF material is realized through simple hydrothermal impregnation, the problem of difficult recycling of powder materials in actual working conditions is solved, quick solid-liquid separation can be realized, the obtained sludge has a reusable value, the treatment cost of the phosphorus-containing wastewater is effectively reduced, and the application has the value of scale application.

Description

Technical Field

[0001] This invention relates to a method for preparing and applying a supported Fe / La-MOF bimetallic framework adsorbent and precipitant for high-phosphorus wastewater. Utilizing the structural characteristics of MOFs, it accelerates the adsorption of PO4 by Fe / La-MOF materials. 3- Its adsorption and sedimentation efficiency makes it suitable for use in wastewater treatment. Background Technology

[0002] Lanthanum hydroxide (La)-based materials possess strong phosphorus binding capacity and good phosphorus stability, making them one of the main materials used in water phosphorus removal agents. The maximum phosphorus adsorption capacity of currently available commercial lanthanum hydroxide is 55.56 mg / g. −1 However, commercially available lanthanum hydroxide releases almost no La ions into water when the pH is greater than 4.0. On the other hand, La is scarce in the Earth's crust and relatively expensive. Therefore, these conditions limit the application of La-based materials for phosphorus removal in water.

[0003] Compared to La-based materials, Fe-based materials are abundant, low-cost, and exhibit good affinity for phosphorus removal from water. Furthermore, the resulting iron phosphate precipitate has good reuse value. However, Fe-based materials alone precipitate PO4. 3- Its ability is limited and it is greatly affected by pH, making it difficult to regulate.

[0004] MOFs (Metal-Organic Frameworks) are porous materials with a periodic network structure, which can be assembled through coordination between organic ligands and metal centers. MOF materials possess high specific surface area and abundant porosity, and their structure and properties are tunable, making them widely used in adsorption / separation fields. Based on this, to obtain efficient, low-cost, and water-stable phosphorus removal materials, this patent application proposes to synthesize a supported Fe / La-MOF bimetallic framework adsorbent and precipitant via an impregnation hydrothermal method, and to obtain a morphology-controllable phosphorus removal agent by adjusting the pH using an alkaline solution. By combining La with inexpensive Fe, the synergistic effect between the two is utilized to improve phosphorus adsorption and precipitation, while also reducing costs. Simultaneously, the supported material can be rapidly separated from water, solving the problems of complex and high-loss recovery of powder materials. Summary of the Invention

[0005] To address the issues of high cost of La-MOF phosphorus removal agents and significant loss of powder materials during recycling, this invention aims to provide a method for preparing a supported Fe / La-MOF bimetallic metal-organic framework adsorbent and precipitant for high-phosphorus wastewater.

[0006] Another objective of this invention is to provide a supported Fe / La-MOF bimetallic-based metal-organic framework adsorbent and precipitant product for high-phosphorus wastewater prepared by the above method.

[0007] Still another object of the present application is to provide the use of the above product.

[0008] The present application is achieved by the following scheme: a preparation method of a supported Fe / La-MOF bimetallic metal organic framework adsorption precipitator for high-phosphorus wastewater, which utilizes the structural advantages of MOFs materials to promote the combination of Fe and La with phosphorus, and further promotes the dispersion of the adsorption material and increases the adsorption capacity of the adsorption material to phosphate based on the solidification of the porous and high-hydrophilic polyurethane sponge carrier, realizes rapid solid-liquid separation, and the sludge has recycling value, and comprises the following steps:

[0009] (1) take a 5*5 cm polyurethane sponge, immerse it in a low-concentration NaOH solution, continuously squeeze it with a kneader to remove the air bubbles remaining in the sponge and make it fully wet, then wash it with water and dry it for standby use;

[0010] (2) place the polyurethane sponge in (1) in a dry beaker, and under magnetic stirring, place La(NO3)3.6H2O and Fe(NO3)3.9H2O in the beaker according to a La / Fe molar ratio of 1:(0.5-5), add N,N-dimethylformamide (DMF) to dissolve them; then dissolve terephthalic acid in DMF, and finally mix the two solutions to form a clear mixed solution;

[0011] (3) place the mixed solution in an ultrasonic reactor for ultrasonic dispersion for 30 min, then add a certain concentration of alkaline solution thereto, adjust the temperature and pH, and control the morphology;

[0012] (4) transfer the mixed solution and the polyurethane sponge substrate to a polytetrafluoroethylene reaction kettle for hydrothermal reaction, control the reaction temperature and time;

[0013] (5) after the reaction is completed, take out the polyurethane sponge, rinse it with DMF and ethanol, and dry it in a vacuum drying box to obtain the supported Fe / La-MOF bimetallic metal organic framework adsorption precipitator in a flower-like or sheet-like shape.

[0014] The present application adopts the introduction of abundant and low-cost Fe-based materials, utilizes the synergistic effect between Fe / La complexes, reduces the feeding ratio of raw materials, reduces the treatment cost, and realizes rapid solid-liquid separation through immobilization treatment, which has great guiding significance for practical application,

[0015] Further, the alkaline solution is any one of ethylenediamine or sodium hydroxide, the concentration is 2mM-1M, the temperature is 30-60℃, and the pH value is adjusted to 8-10.

[0016] The hydrothermal reaction temperature is 90-150℃, and the reaction time is 10-24 h.

[0017] The application also provides a supported Fe / La-MOF bimetallic metal-organic framework adsorption precipitator for high-phosphorus wastewater.

[0018] The application also provides application of the supported Fe / La-MOF bimetallic metal-organic framework adsorption precipitator to rapid removal of high-phosphorus wastewater.

[0019] The adsorption performance test of the Fe-La-MOF phosphorus removal agent is carried out in a conical flask, 0.1 g of the phosphorus removal agent is added to 50 mL of a 20 mg / L orthophosphate solution, the conical flask is placed in a shaker for oscillation adsorption for 2 h, then it is left to stand, the supernatant is taken by centrifugation, and the removal amount of the phosphorus removal agent to the phosphate is determined.

[0020] The application relates to a preparation method, product and application of a supported Fe / La-MOF bimetallic metal-organic framework adsorption precipitator for high-phosphorus wastewater. 3- The La / Fe bimetallic adsorption precipitator is constructed by using the structural advantages of MOFs materials, so that Fe and La can quickly capture PO4 3- in water, the phosphorus-containing wastewater is quickly removed, the supported Fe / La-MOF material is efficiently supported by simple hydrothermal impregnation, the problem of difficult recycling of powder materials in actual working conditions is solved, quick solid-liquid separation can be achieved, the sludge obtained has a recycling value, the treatment cost of the phosphorus-containing wastewater is effectively reduced, and the application has a scale application value.

[0021] The application has the following advantages:

[0022] (1) The application provides a preparation method and application of a supported Fe / La-MOF bimetallic metal-organic framework adsorption precipitator for high-phosphorus wastewater. 3- The porous polyurethane sponge is used as a substrate, and the supported Fe / La-MOF material is synthesized by one-step solvothermal method.

[0023] (2) The supported adsorption precipitator can realize quick solid-liquid separation, the precipitate has a recycling value, the polyurethane sponge can be regenerated by washing and recycled, and the stability is good.

[0024] (3) The preparation method of the supported Fe / La-MOF adsorption precipitator material is simple and controllable, the pore structure is rich, the adsorption capacity is large, the feeding ratio is effectively reduced, the wastewater treatment cost is reduced, and the application has a potential application prospect in the field of environmental governance. DETAILED DESCRIPTION

[0025] The application is further illustrated by examples.

[0026] Example 1

[0027] A supported Fe / La-MOF bimetallic metal organic framework adsorption precipitator for high-phosphorus wastewater utilizes the structure of MOFs material to improve the binding force of Fe and La to phosphorus, and based on the solid support of porous and highly hydrophilic polyurethane sponge carrier, further promotes the dispersion of the adsorption material and improves the adsorption capacity of the adsorption material to phosphate, realizes rapid solid-liquid separation, and is prepared according to the following steps:

[0028] (1) Take a 5*5 cm polyurethane sponge, immerse it in a low-concentration NaOH solution, continuously squeeze it with a kneader to remove the air bubbles remaining in the sponge and make it fully wet, then wash it with water, and dry the treated polyurethane sponge for later use;

[0029] (2) Put the polyurethane sponge treated in (1) into a dry beaker, and under magnetic stirring, put La(NO3)3·6H2O and Fe(NO3)3·9H2O in the beaker according to a La / Fe molar ratio of 1:1, and add N,N-dimethylformamide (DMF) to dissolve them; then, dissolve terephthalic acid in DMF, and finally, mix the two solutions to form a clear mixed solution;

[0030] (3) Put the mixed solution into an ultrasonic reactor for ultrasonic dispersion for 30 min, and add 1M NaOH solution to it at a temperature of 50℃ to adjust the pH to 10 to control the morphology;

[0031] (4) Transfer the mixed solution and the polyurethane sponge substrate to a polytetrafluoroethylene reaction kettle, and perform hydrothermal reaction at 150℃ for 15h;

[0032] (5) After the reaction is completed, take out the polyurethane sponge, rinse it with DMF and ethanol, and dry it in a vacuum drying box to obtain the supported Fe / La-MOF bimetallic metal organic framework adsorption precipitator in the form of flower or sheet.

[0033] The prepared adsorption precipitator has an adsorption removal rate of PO4 3- of 87.3%.

[0034] Example 2

[0035] A supported Fe / La-MOF bimetallic metal organic framework adsorption precipitator for high-phosphorus wastewater is prepared according to the following steps, which is similar to the steps of Example 1.

[0036] (1) Take 5*5 cm polyurethane sponge, immerse it in low concentration NaOH solution, squeeze it with kneading to remove the bubbles remaining in the middle of the sponge and make it fully wet, then wash it with water, dry the treated polyurethane sponge for standby;

[0037] (2) Put the treated polyurethane sponge in (1) into a dry beaker, and under magnetic stirring, put La(NO3)3·6H2O and Fe(NO3)3·9H2O into the beaker according to the molar ratio of La / Fe being 1:2, add N,N-dimethylformamide (DMF) to dissolve them; then, dissolve terephthalic acid in DMF; finally, mix the two solutions to form a clear mixed solution;

[0038] (3) Put the mixed solution into an ultrasonic reactor for ultrasonic dispersion for 30 min, then add 2mM ethylenediamine solution to it, adjust the temperature to 60℃ and the pH value to 9 to control the morphology;

[0039] (4) Transfer the mixed solution of step (3) and the polyurethane sponge substrate to a polytetrafluoroethylene reactor, and perform hydrothermal reaction at 110℃ for 20h;

[0040] (5) After the reaction is completed, take out the polyurethane sponge, rinse it with DMF and ethanol, and dry it in a vacuum drying box to obtain a supported flower-shaped Fe / La-MOF bimetallic metal organic framework adsorption precipitator.

[0041] The prepared adsorption precipitator has a PO4 3- removal rate of 70.7%.

[0042] Example 3

[0043] A supported Fe / La-MOF bimetallic metal organic framework adsorption precipitator for high-phosphorus wastewater is prepared according to the following steps, which are similar to those in Example 1:

[0044] (1) Take 5*5 cm polyurethane sponge, immerse it in low concentration NaOH solution, squeeze it with kneading to remove the bubbles remaining in the middle of the sponge and make it fully wet, then wash it with water, dry the treated polyurethane sponge for standby;

[0045] (2) Put the treated polyurethane sponge in (1) into a dry beaker, and under magnetic stirring, put La(NO3)3·6H2O and Fe(NO3)3·9H2O into the beaker according to the molar ratio of La / Fe being 1:5, add N,N-dimethylformamide (DMF) to dissolve them; then, dissolve terephthalic acid in DMF; finally, mix the two solutions to form a clear mixed solution;

[0046] (3) The mixed solution of step (3) is placed in an ultrasonic reactor for ultrasonic dispersion for 30 min, and then 0.5M ethylenediamine solution is added thereto, the temperature is adjusted to 30°C, and the pH value is adjusted to 10 to control the morphology;

[0047] (4) The mixed solution and the polyurethane sponge substrate are transferred to a polytetrafluoroethylene reactor, and a hydrothermal reaction is performed, with the reaction temperature and time being controlled to be 120°C and 24h;

[0048] (5) After the reaction is completed, the polyurethane sponge is taken out, washed with DMF and ethanol, and dried in a vacuum drying box, to obtain the supported sheet-shaped Fe / La-MOF bimetallic metal organic framework adsorption precipitator.

[0049] The prepared adsorption precipitator has an adsorption removal rate of PO4 3- of 69.5%.

[0050] Example 4

[0051] A supported Fe / La-MOF bimetallic metal organic framework adsorption precipitator for high-phosphorus wastewater is prepared according to the following steps, which are similar to those of Example 1:

[0052] (1) A 5*5cm polyurethane sponge is soaked in a low-concentration NaOH solution, squeezed with a kneader to remove the air bubbles remaining in the sponge and to make it fully wet, and then washed with water. The treated polyurethane sponge is dried for standby use;

[0053] (2) The treated polyurethane sponge in (1) is placed in a dry beaker, and under magnetic stirring, La(NO3)3·6H2O and Fe(NO3)3·9H2O are placed in the beaker according to a La / Fe molar ratio of 1:1, and N,N-dimethylformamide (DMF) is added to dissolve them. Then terephthalic acid is dissolved in DMF. Finally, the two solutions are mixed to form a clear mixed solution;

[0054] (3) The mixed solution is placed in an ultrasonic reactor for ultrasonic dispersion for 30 min, and then 1M NaOH solution is added thereto, the temperature is adjusted to 40°C, and the pH value is adjusted to 9 to control the morphology;

[0055] (4) The mixed solution and the polyurethane sponge substrate are transferred to a polytetrafluoroethylene reactor, and a hydrothermal reaction is performed at 110°C for 20h;

[0056] (5) After the reaction is completed, the polyurethane sponge is taken out, washed with DMF and ethanol, and dried in a vacuum drying box, to obtain the supported flower-shaped Fe / La-MOF bimetallic metal organic framework adsorption precipitator.

[0057] The prepared adsorptive precipitant has an adsorption removal rate of 74.5% for PO4 3- .

Claims

1. A preparation method of a supported Fe / La-MOF bimetallic metal-organic framework adsorption precipitant for high-phosphorus wastewater, characterized in that, Utilize the structure of MOFs material to improve the binding force of Fe and La to phosphorus, and further promote the dispersion of adsorption material and improve the adsorption capacity of phosphate based on the solidification of porous and high hydrophilic polyurethane sponge carrier, realize rapid solid-liquid separation, including the following steps: (1) Take 5*5 cm polyurethane sponge, immerse it in low concentration NaOH solution, continuously squeeze with kneading to remove the residual bubbles in the sponge and make it fully wet, then wash it with water, dry the treated polyurethane sponge and reserve it; (2) Put the polyurethane sponge treated in (1) into a dry beaker, and under magnetic stirring, put La(NO3)3·6H2O and Fe(NO3)3·9H2O into the beaker according to the molar ratio of La / Fe being 1: (0.5~5), add N,N-dimethylformamide DMF to dissolve them; then, dissolve terephthalic acid in DMF, finally, mix the two solutions to form a clear mixed solution; (3) Put the mixed solution into an ultrasonic reactor for ultrasonic dispersion for 30 min, add an alkaline solution thereto at a temperature of 30~60℃ to control the morphology by adjusting the pH to 8~10; (4) Transfer the mixed solution and the polyurethane sponge substrate into a polytetrafluoroethylene reactor for hydrothermal reaction; (5) After the reaction is completed, take out the polyurethane sponge, rinse it with DMF and ethanol, and dry it in a vacuum drying box to obtain a supported flower-shaped or sheet-shaped Fe / La-MOF bimetallic metal organic framework adsorption precipitator.

2. The preparation method of a supported Fe / La-MOF bimetallic metal-organic framework adsorption precipitant for high-phosphorus wastewater according to claim 1, characterized in that, In step (3), the alkaline solution is any one of ethylenediamine or sodium hydroxide, and the concentration is 2mM~1M.

3. The preparation method of a supported Fe / La-MOF bimetallic metal-organic framework adsorption precipitant for high-phosphorus wastewater according to claim 1, characterized in that, In step (4), the hydrothermal reaction temperature is 90~150℃, and the reaction time is 10~24 h.

4. The preparation method of a supported Fe / La-MOF bimetallic metal-organic framework adsorption precipitation agent for high-phosphorus wastewater according to any one of claims 1 to 3, characterized in that, Prepare according to the following steps: (1) Take 5*5 cm polyurethane sponge, immerse it in low concentration NaOH solution, continuously squeeze with kneading to remove the residual bubbles in the sponge and make it fully wet, then wash it with water, dry the treated polyurethane sponge and reserve it; (2) Put the polyurethane sponge treated in (1) into a dry beaker, and under magnetic stirring, put La(NO3)3·6H2O and Fe(NO3)3·9H2O into the beaker according to the molar ratio of La / Fe being 1:1, add N,N-dimethylformamide (DMF) to dissolve them; then, dissolve terephthalic acid in DMF, finally, mix the two solutions to form a clear mixed solution; (3) Put the mixed solution into an ultrasonic reactor for ultrasonic dispersion for 30 min, add 1M NaOH solution thereto at a temperature of 50℃ to control the morphology by adjusting the pH to 10; (4) Transfer the mixed solution and the polyurethane sponge substrate into a polytetrafluoroethylene reactor for hydrothermal reaction at 150℃ for 15h; (5) After the reaction is completed, take out the polyurethane sponge, rinse it with DMF and ethanol, and dry it in a vacuum drying box to obtain a supported flower-shaped or sheet-shaped Fe / La-MOF bimetallic metal organic framework adsorption precipitator.

5. The preparation method of a supported Fe / La-MOF bimetallic metal-organic framework adsorption precipitant for high-phosphorus wastewater according to any one of claims 1 to 3, characterized in that, Prepare according to the following steps: (1) Take 5*5 cm polyurethane sponge, immerse it in low concentration NaOH solution, squeeze it with kneading to remove the bubbles remaining in the middle of the sponge and make it fully wet, then wash it with water, dry the treated polyurethane sponge for standby; (2) Put the treated polyurethane sponge in (1) into a dry beaker, and under magnetic stirring, put La(NO3)3·6H2O and Fe(NO3)3·9H2O into the beaker according to the molar ratio of La / Fe being 1:2, add N,N-dimethylformamide (DMF) to dissolve them; then, dissolve terephthalic acid in DMF; finally, mix the two solutions to form a clear mixed solution; (3) Put the mixed solution into an ultrasonic reactor for ultrasonic dispersion for 30 min, then add 2mM ethylenediamine solution to it, adjust the temperature to 60℃ and the pH value to 9 to control the morphology; (4) Transfer the mixed solution of step (3) and the polyurethane sponge substrate into a polytetrafluoroethylene reactor, and perform hydrothermal reaction at 110℃ for 20h; (5) After the reaction is completed, take out the polyurethane sponge, rinse it with DMF and ethanol, and dry it in a vacuum drying box to obtain the supported flower-shaped Fe / La-MOF bimetallic metal organic framework adsorption precipitator.

6. The preparation method of a supported Fe / La-MOF bimetallic metal-organic framework adsorption precipitant for high-phosphorus wastewater according to any one of claims 1 to 3, characterized in that, Prepare according to the following steps: (1) Take 5*5 cm polyurethane sponge, immerse it in low concentration NaOH solution, squeeze it with kneading to remove the bubbles remaining in the middle of the sponge and make it fully wet, then wash it with water, dry the treated polyurethane sponge for standby; (2) Put the treated polyurethane sponge in (1) into a dry beaker, and under magnetic stirring, put La(NO3)3·6H2O and Fe(NO3)3·9H2O into the beaker according to the molar ratio of La / Fe being 1:5, add N,N-dimethylformamide (DMF) to dissolve them; then, dissolve terephthalic acid in DMF; finally, mix the two solutions to form a clear mixed solution; (3) Put the mixed solution of step (3) into an ultrasonic reactor for ultrasonic dispersion for 30 min, then add 0.5M ethylenediamine solution to it, adjust the temperature to 30℃ and the pH value to 10 to control the morphology; (4) Transfer the mixed solution and the polyurethane sponge substrate into a polytetrafluoroethylene reactor, and perform hydrothermal reaction, control the reaction temperature and time to be 120℃ and 24h; (5) After the reaction is completed, take out the polyurethane sponge, rinse it with DMF and ethanol, and dry it in a vacuum drying box to obtain the supported sheet-shaped Fe / La-MOF bimetallic metal organic framework adsorption precipitator.

7. The preparation method of a supported Fe / La-MOF bimetallic metal-organic framework adsorption precipitant for high-phosphorus wastewater according to any one of claims 1 to 3, characterized in that, Prepare according to the following steps: (1) Take 5*5 cm polyurethane sponge, immerse it in low concentration NaOH solution, squeeze it with kneading to remove the bubbles remaining in the middle of the sponge and make it fully wet, then wash it with water, dry the treated polyurethane sponge for standby; (2) The polyurethane sponge treated in (1) is placed in a dry beaker, and under magnetic stirring, La(NO3)3.6H2O and Fe(NO3)3.9H2O are placed in the beaker according to a molar ratio of La / Fe of 1:1, and N,N-dimethylformamide (DMF) is added to dissolve them; then terephthalic acid is dissolved in DMF; finally, the two solutions are mixed to form a clear mixed solution; (3) The mixed solution is placed in an ultrasonic reactor for ultrasonic dispersion for 30 min, and then 1 M NaOH solution is added thereto, and the temperature is adjusted to 40°C and the pH value is adjusted to 9 to control the morphology; (4) The mixed solution and the polyurethane sponge substrate are transferred to a polytetrafluoroethylene reactor, and hydrothermal reaction is carried out at 110°C for 20 h; (5) After the reaction is completed, the polyurethane sponge is taken out, washed with DMF and ethanol, and dried in a vacuum drying box, to obtain a supported flower-shaped Fe / La-MOF bimetallic metal organic framework adsorption precipitator.

8. A supported Fe / La-MOF bimetallic metal-organic framework adsorption precipitant for high phosphorus wastewater, characterized in that Prepared according to any one of claims 1-7.

9. Use of the supported Fe / La-MOF bimetallic metal organic framework adsorption precipitator according to claim 8 for rapid removal of high-phosphorus wastewater.