Preparation method of supported Fe / La-MOF bimetal-based metal organic framework adsorption precipitator for high-phosphorus wastewater as well as product and application of supported Fe / La-MOF bimetal-based metal organic framework adsorption precipitator

Abstract

The invention relates to a preparation method of a supported Fe / La-MOF bimetal-based metal organic framework adsorption precipitant for high-phosphorus wastewater as well as a product and application of the supported Fe / La-MOF bimetal-based metal organic framework adsorption precipitant, a porous La / Fe bimetal-based adsorption precipitant with a large specific surface area is constructed by utilizing the structural advantages of an MOFs material, so that Fe and La are promoted to rapidly capture PO4 < 3-> in water, and rapid removal of phosphorus-containing wastewater is realized; in addition, efficient immobilization of the supported Fe / La-MOF material is achieved through simple hydrothermal impregnation, the problem that the powder material is difficult to recycle in the actual working condition is solved, solid-liquid separation can be rapidly achieved, the obtained sludge has the recycling value, the treatment cost of phosphorus-containing wastewater is effectively reduced, and the method has the large-scale application value.

Description

Technical Field

[0001] The present invention relates to a preparation method and application of a loaded Fe / La-MOF bimetallic metal organic framework adsorption precipitant for high-phosphorus wastewater, which utilizes the characteristics of the MOFs framework structure to accelerate the adsorption of PO4 by Fe / La-MOF materials. 3- The adsorption and precipitation efficiency is high and it is used in sewage treatment. Background Art

[0002] La-based materials have strong phosphorus-binding ability and good stability, and are currently one of the main materials for phosphorus removal in water. The maximum adsorption capacity of commercial lanthanum hydroxide for phosphorus is 55.56 mg / g −1 However, when the pH is greater than 4.0, commercially available lanthanum hydroxide hardly releases La ions into the water. On the other hand, the La content in the earth's crust is low and the price is relatively expensive. Therefore, these conditions limit the application of La-based materials in phosphorus removal in water.

[0003] Compared with La-based materials, Fe-based materials are abundant in reserves, low in cost, have good affinity for removing phosphorus from water, and the iron phosphate precipitate formed also has good recycling value. 3- The capacity is limited and is greatly affected by pH, making it difficult to regulate.

[0004] MOFs is a porous material with a periodic network structure, which can be assembled by the coordination of organic ligands and metal centers. MOFs materials have high specific surface area and rich porosity, and their structure and performance are adjustable, and they are widely used in the field of adsorption / separation. Based on this, in order to obtain efficient, low-cost, and water-stable phosphorus removal materials, this patent application intends to synthesize a supported Fe / La-MOF bimetallic metal organic framework adsorption precipitant by an immersion hydrothermal method, and obtain a morphology-controllable phosphorus removal agent by regulating the pH with an alkaline solution. By combining La with cheap Fe, the synergistic effect between the two is used to improve the adsorption and precipitation of phosphorus, and to reduce costs. At the same time, the supported material can be quickly separated from the water, solving the problem of complex recovery and high loss of powder materials. Summary of the invention

[0005] In view of the high cost of La-MOF dephosphorizer and the large loss rate of powder material during recycling, the present invention aims to provide a method for preparing a supported Fe / La-MOF bimetallic metal organic framework adsorption precipitant for high-phosphorus wastewater.

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

[0007] Another object of the present invention is to provide an application of the above product.

[0008] The purpose of the present invention is achieved through the following scheme: a preparation method of a loaded Fe / La-MOF bimetallic metal organic framework adsorption precipitant for high-phosphorus wastewater, which utilizes the structural advantages of MOFs materials to promote the improvement of the binding force of Fe and La to phosphorus, and further promotes the dispersion of the adsorption material and improves the adsorption capacity of phosphate based on the solid support of a porous, highly hydrophilic polyurethane sponge carrier, and realizes rapid solid-liquid separation, and the sludge has a recycling value, comprising the following steps: (1) Take a 5*5cm polyurethane sponge, soak it in a low-concentration NaOH solution, and squeeze it continuously with a kneading machine to remove the bubbles remaining in the middle of the sponge and make it fully moist. Then wash it with water and dry it for later use; (2) The 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 at a La / Fe molar ratio of 1:(0.5-5), and N,N-dimethylformamide (DMF) is added to dissolve them; terephthalic acid is then dissolved in DMF, and finally the two solutions are mixed to form a clear mixed solution; (3) The mixed solution was placed in an ultrasonic reactor for ultrasonic dispersion for 30 min, and then a certain concentration of alkaline solution was added to it, and the temperature and pH were adjusted to control the morphology; (4) transferring the mixed solution and the polyurethane sponge substrate into a polytetrafluoroethylene reactor for hydrothermal reaction, and controlling the reaction temperature and time; (5) After the reaction is completed, the polyurethane sponge is taken out, rinsed with DMF and ethanol, and dried in a vacuum drying oven to obtain a loaded flower-shaped or sheet-shaped Fe / La-MOF bimetallic metal organic framework adsorption precipitant.

[0009] The present invention introduces Fe-based materials with abundant reserves and low cost, utilizes the synergistic effect between Fe / La complexes, reduces the feed ratio of raw materials, reduces the treatment cost, and at the same time, the immobilization treatment can achieve rapid solid-liquid separation, which has great guiding significance for practical applications. Furthermore, the alkaline solution is any one of ethylenediamine or sodium hydroxide, with a concentration of 2mM~1M; the temperature is 30~60°C, and the pH value is adjusted to 8~10.

[0010] The hydrothermal reaction temperature is 90-150°C, and the reaction time is 10-24 h.

[0011] The present invention also provides a supported Fe / La-MOF bimetallic metal organic framework adsorption precipitant for high-phosphorus wastewater, which is prepared according to any of the above methods.

[0012] The present invention also provides an application of a supported Fe / La-MOF bimetallic metal organic framework adsorption precipitant for rapid removal of high-phosphorus wastewater.

[0013] The adsorption performance test of the Fe-La-MOF dephosphorus agent was carried out in a conical flask. 0.1 g of the dephosphorus agent was added to 50 mL of 20 mg / L orthophosphate solution. The conical flask was placed in an oscillator for oscillation and adsorption for 2 hours, then allowed to stand and centrifuged to obtain the supernatant to determine the amount of phosphate removed by the dephosphorus agent.

[0014] The present invention relates to a preparation method, product and application of a loaded Fe / La-MOF bimetallic metal organic framework adsorption precipitation agent for high-phosphorus wastewater, which utilizes the structural advantages of MOFs materials to construct a La / Fe bimetallic adsorption precipitation material with large specific surface area and porosity, so as to enable Fe and La to quickly capture PO4 in water. 3- , realizing the rapid removal of phosphorus-containing wastewater; in addition, the efficient immobilization of the loaded Fe / La-MOF material is achieved through simple hydrothermal impregnation, solving the problem of difficult recycling of powder materials in actual working conditions, and can quickly separate the solid and liquid. The obtained sludge has reusable value, effectively reducing the cost of treating phosphorus-containing wastewater and having the value of large-scale application.

[0015] The present invention has the following advantages: (1) The present invention proposes a preparation method and application of a loaded Fe / La-MOF bimetallic metal organic framework adsorption precipitant for high phosphorus wastewater, which uses a porous polyurethane sponge as a substrate and a one-step solvothermal method to synthesize the loaded Fe / La-MOF material. 3- The synergistic effect effectively promotes the rapid adsorption and precipitation of phosphorus in water. At the same time, the porous polyurethane can accelerate the contact area between pollutants and adsorption and precipitation materials, which is beneficial to the adsorption and precipitation reaction.

[0016] (2) The supported adsorption precipitant proposed in the present invention can achieve rapid solid-liquid separation, and the precipitate has recycling value. Moreover, the polyurethane sponge can be regenerated by washing and can be recycled with good stability.

[0017] (3) The preparation method of the loaded Fe / La-MOF adsorption precipitation material proposed in the present invention is not only simple and controllable, but also has a rich pore structure and a large adsorption capacity, which can effectively reduce the feed ratio and reduce the cost of wastewater treatment, and has potential application prospects in the field of environmental governance. DETAILED DESCRIPTION

[0018] The present invention is further described by way of examples.

[0019] Example 1 A supported Fe / La-MOF bimetallic metal organic framework adsorption precipitant for high-phosphorus wastewater utilizes the structure of MOFs materials to improve the binding force of Fe and La to phosphorus, and further promotes the dispersion of the adsorption material and improves the adsorption capacity of phosphate based on the solid support of a porous and highly hydrophilic polyurethane sponge carrier to achieve rapid solid-liquid separation. The preparation is carried out according to the following steps: (1) Take a 5*5cm polyurethane sponge, soak it in a low-concentration NaOH solution, and squeeze it continuously with a kneading machine to remove the bubbles remaining in the middle of the sponge and make it fully moist. Then wash it with water. The treated polyurethane sponge is dried and set aside; (2) placing the polyurethane sponge treated in (1) in a dry beaker, and under magnetic stirring, placing La(NO3)3·6H2O and Fe(NO3)3·9H2O in the beaker at a La / Fe molar ratio of 1:1, adding N,N-dimethylformamide (DMF) to dissolve them; then, dissolving terephthalic acid in DMF, and finally, mixing the two solutions to form a clear mixed solution; (3) The mixed solution was placed in an ultrasonic reactor for ultrasonic dispersion for 30 min, 1 M NaOH solution was added at 50 °C, and the pH was adjusted to 10 to control the morphology; (4) The mixed solution and the polyurethane sponge substrate were transferred to a polytetrafluoroethylene reactor and subjected to a hydrothermal reaction at 150 °C for 15 h; (5) After the reaction is completed, the polyurethane sponge is taken out, rinsed with DMF and ethanol, and dried in a vacuum drying oven to obtain a loaded flower-shaped or sheet-shaped Fe / La-MOF bimetallic metal organic framework adsorption precipitant.

[0020] The prepared adsorption precipitant has an effect on PO4 3- The adsorption removal efficiency was 87.3%.

[0021] Example 2 A supported Fe / La-MOF bimetallic metal organic framework adsorption precipitant for high phosphorus wastewater is prepared by the following steps similar to those in Example 1: (1) Take a 5*5cm polyurethane sponge, soak it in a low-concentration NaOH solution, and squeeze it continuously with a kneading machine to remove the bubbles remaining in the middle of the sponge and make it fully moist. Then wash it with water and dry the treated polyurethane sponge for later use; (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 La / Fe molar ratio of 1:2, 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 was placed in an ultrasonic reactor for ultrasonic dispersion for 30 min, and then a 2 mM ethylenediamine solution was added thereto. The temperature was adjusted to 60 °C and the pH value was adjusted to 9 to control the morphology. (4) transferring the mixed solution of step (3) and the polyurethane sponge substrate into a polytetrafluoroethylene reactor and performing a hydrothermal reaction at 110° C. for 20 h; (5) After the reaction is completed, the polyurethane sponge is taken out, rinsed with DMF and ethanol, and dried in a vacuum drying oven to obtain a loaded flower-like Fe / La-MOF bimetallic metal organic framework adsorption precipitant.

[0022] The prepared adsorption precipitant has an effect on PO4 3- The adsorption removal efficiency was 70.7%.

[0023] Example 3 A supported Fe / La-MOF bimetallic metal organic framework adsorption precipitant for high phosphorus wastewater is prepared by the following steps similar to those in Example 1: (1) Take a 5*5cm polyurethane sponge, soak it in a low-concentration NaOH solution, and squeeze it continuously with a kneading machine to remove the bubbles remaining in the middle of the sponge and make it fully moist. Then wash it with water and dry the treated polyurethane sponge for later use; (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 La / Fe molar ratio of 1:5, 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) placing the mixed solution of step (3) in an ultrasonic reactor for ultrasonic dispersion for 30 min, adding 0.5 M ethylenediamine solution thereto, adjusting the temperature to 30° C. and the pH value to 10 to control the morphology; (4) transferring the mixed solution and the polyurethane sponge substrate into a polytetrafluoroethylene reactor for a hydrothermal reaction, and controlling the reaction temperature and time to be 120°C and 24h; (5) After the reaction is completed, the polyurethane sponge is taken out, rinsed with DMF and ethanol, and dried in a vacuum drying oven to obtain a loaded sheet-like Fe / La-MOF bimetallic metal organic framework adsorption precipitant.

[0024] The prepared adsorption precipitant has an effect on PO4 3- The adsorption removal efficiency was 69.5%.

[0025] Example 4 A supported Fe / La-MOF bimetallic metal organic framework adsorption precipitant for high phosphorus wastewater is prepared by the following steps similar to those in Example 1: (1) Take a 5*5cm polyurethane sponge, soak it in a low-concentration NaOH solution, and squeeze it continuously with a kneading machine to remove the bubbles remaining in the middle of the sponge and make it fully moist. Then wash it with water and dry the treated polyurethane sponge for later use; (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 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; (3) The mixed solution was placed in an ultrasonic reactor for ultrasonic dispersion for 30 min, and then 1 M NaOH solution was added thereto. The temperature was adjusted to 40 °C and the pH value was adjusted to 9 to control the morphology. (4) The mixed solution and the polyurethane sponge substrate were transferred to a polytetrafluoroethylene reactor and subjected to a hydrothermal reaction at 110 °C for 20 h; (5) After the reaction is completed, the polyurethane sponge is taken out, rinsed with DMF and ethanol, and dried in a vacuum drying oven to obtain a loaded flower-like Fe / La-MOF bimetallic metal organic framework adsorption precipitant.

[0026] The prepared adsorption precipitant has an effect on PO4 3- The adsorption removal efficiency was 74.5%.

Claims

1. A method for preparing a supported Fe / La-MOF bimetallic metal organic framework adsorption precipitant for high-phosphorus wastewater, characterized in that: The structure of MOFs materials is utilized to improve the binding force of Fe and La to phosphorus, and based on the immobilization of porous and highly hydrophilic polyurethane sponge carriers, the dispersion of adsorbent materials is further promoted and the adsorption capacity of phosphate is increased to achieve rapid solid-liquid separation, including the following steps: (1) Take a 5*5cm polyurethane sponge, soak it in a low-concentration NaOH solution, and squeeze it continuously with a kneading machine to remove the bubbles remaining in the middle of the sponge and make it fully moist. Then wash it with water. The treated polyurethane sponge is dried and set aside; (2) placing the polyurethane sponge treated in (1) in a dry beaker, and placing La(NO3)3·6H2O and Fe(NO3)3·9H2O in a beaker at a La / Fe molar ratio of 1:(0.5-5) under magnetic stirring, adding N,N-dimethylformamide (DMF) to dissolve them; then, dissolving terephthalic acid in DMF, and finally, mixing the two solutions to form a clear mixed solution; (3) The mixed solution was placed in an ultrasonic reactor for ultrasonic dispersion for 30 min, and an alkaline solution was added thereto at a temperature of 30-60°C to adjust the pH to 8-10 to control the morphology; (4) transferring the mixed solution and the polyurethane sponge substrate into a polytetrafluoroethylene reactor for a hydrothermal reaction; (5) After the reaction is completed, the polyurethane sponge is taken out, rinsed with DMF and ethanol, and dried in a vacuum drying oven to obtain a loaded flower-shaped or sheet-shaped Fe / La-MOF bimetallic metal organic framework adsorption precipitant.

2. A method for preparing 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. A method for preparing 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°C, and the reaction time is 10-24 h.

4. A method for preparing 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 as follows: (1) Take a 5*5cm polyurethane sponge, soak it in a low-concentration NaOH solution, and squeeze it continuously with a kneading machine to remove the bubbles remaining in the middle of the sponge and make it fully moist. Then wash it with water. The treated polyurethane sponge is dried and set aside; (2) placing the polyurethane sponge treated in (1) in a dry beaker, and under magnetic stirring, placing La(NO3)3·6H2O and Fe(NO3)3·9H2O in the beaker at a La / Fe molar ratio of 1:1, adding N,N-dimethylformamide (DMF) to dissolve them; then, dissolving terephthalic acid in DMF, and finally, mixing the two solutions to form a clear mixed solution; (3) The mixed solution was placed in an ultrasonic reactor for ultrasonic dispersion for 30 min, 1 M NaOH solution was added at 50 °C, and the pH was adjusted to 10 to control the morphology; (4) The mixed solution and the polyurethane sponge substrate were transferred to a polytetrafluoroethylene reactor and subjected to a hydrothermal reaction at 150 °C for 15 h; (5) After the reaction is completed, the polyurethane sponge is taken out, rinsed with DMF and ethanol, and dried in a vacuum drying oven to obtain a loaded flower-shaped or sheet-shaped Fe / La-MOF bimetallic metal organic framework adsorption precipitant.

5. A method for preparing 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 as follows: (1) Take a 5*5cm polyurethane sponge, soak it in a low-concentration NaOH solution, and squeeze it continuously with a kneading machine to remove the bubbles remaining in the middle of the sponge and make it fully moist. Then wash it with water and dry the treated polyurethane sponge for later use; (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 La / Fe molar ratio of 1:2, 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 was placed in an ultrasonic reactor for ultrasonic dispersion for 30 min, and then a 2 mM ethylenediamine solution was added thereto. The temperature was adjusted to 60 °C and the pH value was adjusted to 9 to control the morphology. (4) transferring the mixed solution of step (3) and the polyurethane sponge substrate into a polytetrafluoroethylene reactor and performing a hydrothermal reaction at 110° C. for 20 h; (5) After the reaction is completed, the polyurethane sponge is taken out, rinsed with DMF and ethanol, and dried in a vacuum drying oven to obtain a loaded flower-like Fe / La-MOF bimetallic metal organic framework adsorption precipitant.

6. A method for preparing 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 as follows: (1) Take a 5*5cm polyurethane sponge, soak it in a low-concentration NaOH solution, and squeeze it continuously with a kneading machine to remove the bubbles remaining in the middle of the sponge and make it fully moist. Then wash it with water and dry the treated polyurethane sponge for later use; (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 La / Fe molar ratio of 1:5, 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) placing the mixed solution of step (3) in an ultrasonic reactor for ultrasonic dispersion for 30 min, adding 0.5 M ethylenediamine solution thereto, adjusting the temperature to 30° C. and the pH value to 10 to control the morphology; (4) transferring the mixed solution and the polyurethane sponge substrate into a polytetrafluoroethylene reactor for a hydrothermal reaction, and controlling the reaction temperature and time to be 120°C and 24h; (5) After the reaction is completed, the polyurethane sponge is taken out, rinsed with DMF and ethanol, and dried in a vacuum drying oven to obtain a loaded sheet-like Fe / La-MOF bimetallic metal organic framework adsorption precipitant.

7. A method for preparing 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 as follows: (1) Take a 5*5cm polyurethane sponge, soak it in a low-concentration NaOH solution, and squeeze it continuously with a kneading machine to remove the bubbles remaining in the middle of the sponge and make it fully moist. Then wash it with water and dry the treated polyurethane sponge for later use; (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 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; (3) The mixed solution was placed in an ultrasonic reactor for ultrasonic dispersion for 30 min, and then 1 M NaOH solution was added thereto. The temperature was adjusted to 40 °C and the pH value was adjusted to 9 to control the morphology. (4) The mixed solution and the polyurethane sponge substrate were transferred to a polytetrafluoroethylene reactor and subjected to a hydrothermal reaction at 110 °C for 20 h; (5) After the reaction is completed, the polyurethane sponge is taken out, rinsed with DMF and ethanol, and dried in a vacuum drying oven to obtain a loaded flower-like Fe / La-MOF bimetallic metal organic framework adsorption precipitant.

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 to 7.

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