Material with EPOA structure as well as preparation method and water treatment application thereof

Abstract

The invention provides a material with an EPOA structure as well as a preparation method and water treatment application thereof. The material disclosed by the invention is named as EPOA-4, and the preparation method comprises the following steps: taking powder aluminum oxide and silica sol as raw materials, taking a binder, a dispersing agent, a thickening agent and a defoaming agent as auxiliary materials, carrying out ball milling and mixing to obtain slurry I, taking polyurethane foam as a template, hanging the slurry, drying, and sintering at high temperature to obtain foamed aluminum oxide; dissolving an inorganic aluminum salt in water, adjusting the pH value to be acidic to prepare slurry II, immersing the slurry II in foamed aluminum oxide, taking out, drying, and carrying out high-temperature roasting to obtain an EPOA-4 precursor; the preparation method comprises the following steps: dissolving iron salt in water to prepare an impregnation liquid, putting an EPOA-4 precursor into the impregnation liquid to carry out a sufficient surface crosslinking reaction, drying, carrying out medium-temperature annealing, and cooling to obtain the EPOA-4 material. The EPOA-4 material does not need additional chemicals in the water treatment process, energy of pollutants in sewage is utilized to activate dissolved oxygen into active oxygen species, the chemical oxygen demand in the sewage is rapidly and effectively reduced, and the green and low-carbon water purification effect is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and particularly to a material with an EPOA structure, a preparation method thereof, and a water treatment application. Background Art

[0002] Industrial wastewater faces unprecedented challenges due to the rapid development of the chemical industry. The types and quantities of pollutants it contains are constantly increasing, and its composition is becoming increasingly complex, which has greatly increased the threshold of treatment technology and correspondingly increased the treatment cost. Traditional water treatment is difficult to cope with the complex and changeable wastewater environment. For example, the commonly used biochemical reaction has limited treatment effect on refractory organic pollutants, and there are problems such as long reaction time, large floor area, and high energy consumption in practical applications. Advanced oxidation is one of the effective technologies for removing refractory organic pollutants, but there are problems such as dependence on oxidation agents, the need for special equipment, and the generation of secondary pollution in engineering applications. In the face of the "dual carbon" goal, traditional water treatment with high energy consumption and low efficiency has become stretched, so it has become an urgent task to develop new green and low-carbon treatment technologies.

[0003] In view of this, based on the Electronic Polarization driving Oxygen Activation Technology (abbreviated as EPOA technology), this patent develops a material with an EPOA structure, named EPOA-4 material, by constructing a multi-functional channel on the surface of the foam alumina with a three-dimensional network special porous structure. Under mild conditions of normal temperature and pressure, EPOA-4 does not require external agents, captures water pollutants and dissolved oxygen (DO) through the multi-functional channel, activates DO into reactive oxygen species using the energy of the pollutants, and realizes the synergistic effect of pollution reduction and carbon reduction during the sewage purification process through the multi-path reaction mechanism of spontaneous oxidation of pollutants and degradation by reactive oxygen species. Summary of the Invention

[0004] The purpose of the present invention is to provide a material with an EPOA structure, a preparation method thereof, and a water treatment application.

[0005] The present invention provides a preparation method of an EPOA-4 material, comprising the following steps:

[0006] (1) After mixing powder alumina and water according to a mass ratio of 15:10, successively add silica sol, binder, dispersant, thickener and water, ball-mill and mix the materials, and then add a few drops of defoamer to form slurry I with a solute ratio of 55-60%wt.

[0007] (2) After washing the polyurethane foam several times with clean water, immerse it in a 10~20%wt alkaline solution and maintain the solution temperature at 55~65℃ for 2~4 hours before drying to roughen the surface for easy slurry attachment.

[0008] (3) The pretreated polyurethane foam is immersed in slurry I, taken out after slurry hanging, and excess slurry I is shaken off. After natural air drying at room temperature for 12 to 24 hours, it is placed in an oven for drying for 12 to 18 hours to obtain a foamed alumina body, which is then placed in a muffle furnace and maintained at 500 to 600°C for 1 to 2 hours, followed by insulation at 1300 to 1500°C for 2 to 4 hours. After the furnace body is naturally cooled, foamed alumina is obtained.

[0009] (4) Inorganic aluminum salt and water are mixed in a mass ratio of 0.7:10, stirred in a water bath maintained at a temperature above 80°C for 30 to 90 minutes, and then acidic solution is slowly added to make the molar ratio of Al3+:H+ in the solution (10-15):10. Stirring is continued in a high temperature water bath for 4 to 6 hours and then cooled to room temperature to obtain slurry II.

[0010] (5) Immerse the foamed alumina prepared above in slurry II, then take out and shake off excess slurry II, place it in an oven to dry for 1 to 3 hours, and then place it in a muffle furnace at 500 to 600°C for 2 to 4 hours to obtain an EPOA-4 precursor.

[0011] (6) Dissolve the iron salt in water to form an impregnation solution and add the EPOA-4 precursor, maintaining the mass ratio of Fe3+ to EPOA-4 precursor at (0.5-3):10. After sufficient reaction, take out and place in an oven to dry for 1-3 hours, then place in a muffle furnace at 400-550°C for 2-4 hours, and after natural cooling, obtain EPOA-4.

[0012] Preferably, the adhesive in step (1) includes polyvinyl alcohol, polytetrafluoroethylene and polyvinylidene fluoride, etc., the dispersant includes polyacrylamide, sodium hexametaphosphate and sodium dodecyl sulfate, etc., the thickener includes sodium carboxymethyl cellulose, β-cyclodextrin and starch, etc., and the defoaming agent is n-butanol.

[0013] Preferably, the mass ratio of silica sol, binder, dispersant, thickener and water added in step (1) is (8-9):(2-3):(0.1-0.2):(0.5-0.8):10.

[0014] Preferably, the alkaline reagent in step (2) includes but is not limited to sodium hydroxide, sodium hydrogen phosphate, ammonia water, etc.

[0015] Preferably, the oven temperature in step (3) is 60~80°C, and the heating rate of the muffle furnace is controlled at 1~5°C per minute.

[0016] Preferably, the inorganic aluminum salts in step (4) include, but are not limited to, pseudo-boehmite, sodium metaaluminate, potassium metaaluminate, etc., and the acidic solutions include, but are not limited to, acetic acid, sulfuric acid, nitric acid, etc.

[0017] Preferably, the oven temperature in step (5) is 80~120°C, and the heating rate of the muffle furnace is controlled at 1~5°C per minute.

[0018] Preferably, the iron salts in step (6) include, but are not limited to, ferric chloride, ferric nitrate, ferric sulfate, etc., either alone or in combination. The oven temperature is 80~100°C, and the heating rate of the muffle furnace is controlled at 5~10°C per minute.

[0019] The present invention also provides an EPOA-4 material prepared according to the above preparation method.

[0020] The present invention also provides the application of the above EPOA-4 material in water treatment.

[0021] In the water treatment application, the EPOA-4 material is directly put into the sewage. Under the action of gravity, the EPOA-4 settles to the bottom, making full contact with the sewage. Aeration is carried out in the sewage, which can increase the DO content in the water. At the same time, the contact and collision between the EPOA-4, DO, and pollutants are increased. Capture occurs in the multifunctional channels on the material surface, and the energy of the pollutants is used to activate DO into reactive oxygen species. Through the multi-path reaction mechanism of spontaneous oxidation of pollutants and degradation by reactive oxygen species, the efficient removal of chemical oxygen demand (COD) in the sewage is achieved.

[0022] The implementation of the present invention has at least the following advantages:

[0023] (1) The preparation method of the EPOA-4 material is simple, and the process is safe and controllable. It does not involve high-pressure sintering, special atmospheres, etc., and is suitable for large-scale production.

[0024] (2) The EPOA-4 material has high mechanical strength, high porosity, and large specific surface area. The components of its multifunctional channels are greatly exposed on the material surface, making it easy to contact with DO and pollutants in water.

[0025] (3) Under mild conditions of normal temperature and pressure, the EPOA-4 material can achieve the efficient removal of COD by contacting with sewage, realizing the water purification effect.

[0026] (4) The EPOA-4 material will not agglomerate during use, and the solid-liquid separation effect is obvious, with high efficiency, and it is convenient for recycling and reuse. Description of the Drawings

[0027] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0028] Figure 1 is a physical diagram of EPOA-4-1 prepared in Example 1.

[0029] Figure 2 is a diagram showing the degradation of COD in pharmaceutical wastewater by EPOA-4-1 prepared in Example 1.

[0030] Figure 3 is a schematic diagram of the purification mechanism of the EPOA-4 material in the water treatment process. Specific Embodiments

[0031] It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs.

[0032] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form also includes the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0033] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention. Example 1

[0034] An embodiment of the EPOA-4 material of the present invention. The preparation method of EPOA-4-1 in this embodiment includes the following steps:

[0035] (1)After stirring and mixing powdered alumina and water at a mass ratio of 15:10, silica sol, polyvinyl alcohol, polyacrylamide, sodium carboxymethylcellulose, and water were added at a mass ratio of 8:2:0.1:0.5:10. After ball milling and mixing, a few drops of n-butanol were added, and finally, slurry I with a solute ratio of 55%wt was formed.

[0036] (2)The polyurethane foam was washed several times with clear water and then immersed in a 10%wt sodium hydroxide solution. The solution temperature was maintained at 55 °C, and after 2 hours, it was dried in an oven for surface roughening modification to facilitate slurry hanging.

[0037] (3)The pretreated polyurethane foam was immersed in slurry I, removed after slurry hanging, and the excess slurry I was shaken off. After natural air drying at room temperature for 24 hours, it was dried in an oven for 12 hours to obtain a foam alumina green body. Then, it was placed in a muffle furnace and heated at a rate of 1 °C / minute and held at 500 °C for 1 hour. Subsequently, it was heated at a rate of 3 °C / minute and held at 1300 °C for 2 hours. After natural cooling with the furnace body, foam alumina was prepared.

[0038] (4)Pseudoboehmite and water were mixed at a mass ratio of 0.7:10, and the temperature was maintained at 85 °C in a water bath and stirred for 30 minutes. Subsequently, concentrated nitric acid was slowly added to make the molar ratio of Al3+ to H+ in the solution 12:10. After stirring for 4 hours under high-temperature water bath conditions, it was cooled to room temperature to obtain slurry II.

[0039] (5)The above-prepared foam alumina was immersed in slurry II, then taken out and the excess slurry II was shaken off, and it was dried in an oven for 1 hour. Subsequently, it was placed in a muffle furnace and heated at a rate of 5 °C / minute and held at 500 °C for 2 hours to obtain the EPOA-4 precursor.

[0040] (6)The iron salt was dissolved in water to form an impregnation solution and added to the EPOA-4 precursor, keeping the mass ratio of Fe3+ to the EPOA-4 precursor 1.5:10. After sufficient reaction, it was taken out and dried in an oven for 2 hours. Then, it was placed in a muffle furnace and heated at a rate of 5 °C / minute and held at 550 °C for 2 hours. After natural cooling, EPOA-4-1 was obtained. Example 2

[0041] An example of the EPOA-4 material of the present invention. The preparation method of EPOA-4-2 in this example includes the following steps:

[0042] (1)After stirring and mixing powdered alumina and water at a mass ratio of 15:10, add silica sol, polyvinyl alcohol, polyacrylamide, β-cyclodextrin and water at a mass ratio of 8:2:0.1:0.5:10. After ball-milling and mixing the materials, add a few drops of n-butanol, and finally form slurry I with a solute proportion of 60%wt.

[0043] (2)Wash the polyurethane foam several times with clean water, immerse it in a 15%wt sodium hydroxide solution, maintain the solution temperature at 60 °C, keep it for 2 hours, and then dry it in an oven to conduct surface roughening modification for facilitating slurry coating.

[0044] (3)Immerse the pretreated polyurethane foam in slurry I, remove it after slurry coating, shake off the excess slurry I, air-dry it naturally at room temperature for 24 hours, then dry it in an oven for 18 hours to obtain a foam alumina green body. Then place it in a muffle furnace, heat it at a heating rate of 2 °C per minute and hold it at 500 °C for 2 hours. Then, heat it at a heating rate of 4 °C per minute and keep it at 1400 °C for 2 hours. After natural cooling with the furnace body, foam alumina is prepared.

[0045] (4)Mix pseudoboehmite and water at a mass ratio of 0.7:10, keep the temperature at 85 °C in a water bath and stir for 60 minutes. Then slowly add concentrated nitric acid to make the molar ratio of Al3+ to H+ in the solution 12:10. After stirring for 4 hours under high-temperature water bath conditions, cool it to room temperature to obtain slurry II.

[0046] (5)Immerse the prepared foam alumina in slurry II, then take it out, shake off the excess slurry II, dry it in an oven for 1 hour, and then place it in a muffle furnace, heat it at a heating rate of 5 °C per minute and hold it at 500 °C for 2 hours to obtain an EPOA-4 precursor.

[0047] (6)Dissolve the iron salt in water to form an impregnation solution and add the EPOA-4 precursor, keep the mass ratio of Fe3+ to the EPOA-4 precursor 0.5:10. After sufficient reaction, take it out and dry it in an oven for 2 hours. Then place it in a muffle furnace, heat it at a heating rate of 5 °C per minute and hold it at 550 °C for 3 hours. After natural cooling, EPOA-4-2 is obtained. Example 3

[0048] An example of the EPOA-4 material of the present invention. The preparation method of EPOA-4-3 in this example includes the following steps:

[0049] (1)After stirring and mixing powdered alumina and water at a mass ratio of 15:10, add silica sol, polyvinyl alcohol, polyacrylamide, sodium carboxymethyl cellulose, and water at a mass ratio of 9:3:0.2:0.7:10. After ball-milling and mixing, add a few drops of n-butanol, and finally form slurry I with a solute ratio of 60%wt.

[0050] (2)Wash the polyurethane foam several times with clean water, immerse it in a 20%wt sodium hydroxide solution, maintain the solution temperature at 65°C, keep it for 2 hours, and then dry it in an oven to conduct surface roughening modification for facilitating slurry coating.

[0051] (3)The pretreated polyurethane foam is immersed in slurry I, removed after slurry coating, shake off the excess slurry I, air-dry it naturally at room temperature for 24 hours, then dry it in an oven for 15 hours to obtain a foam alumina green body, and then place it in a muffle furnace, heat it at a heating rate of 2°C / minute and hold it at 550°C for 1 hour, then heat it at a heating rate of 5°C / minute and keep it at 1500°C for 4 hours, and after natural cooling with the furnace body, foam alumina is prepared.

[0052] (4)Mix boehmite and water at a mass ratio of 0.7:10, stir in a water bath at a temperature of 85°C for 90 minutes, then slowly add concentrated nitric acid to make the molar ratio of Al3+ to H+ in the solution 15:10, and stir for 6 hours under high-temperature water bath conditions and then cool to room temperature to obtain slurry II.

[0053] (5)Immerse the prepared foam alumina in slurry II, then take it out, shake off the excess slurry II, dry it in an oven for 3 hours, and then place it in a muffle furnace, heat it at a heating rate of 10°C / minute and hold it at 600°C for 2 hours to obtain the EPOA-4 precursor.

[0054] (6)Dissolve the iron salt in water to form an impregnating solution and add the EPOA-4 precursor, keep the mass ratio of Fe3+ to the EPOA-4 precursor 3:10, after sufficient reaction, take it out and dry it in an oven for 3 hours, then place it in a muffle furnace, heat it at a heating rate of 10°C / minute and hold it at 550°C for 2 hours, and after natural cooling, obtain EPOA-4-3. Specific application example

[0055] This embodiment provides an example of the application of the EPOA-4 material in water treatment, specifically as follows:

[0056] Place the EPOA-4 material and sewage in a reaction vessel at a mass ratio of 1:3. Under the action of gravity, EPOA-4 settles to the bottom. Maintain normal temperature and pressure and the natural pH value. Aerate appropriately to increase the DO in the water and the contact and collision between EPOA-4 and sewage. After reacting for 4 hours, remove the purified water, add sewage again, and perform cyclic treatment, and monitor the COD of the influent and effluent. EPOA-4 can utilize the energy of pollutants to activate DO into reactive oxygen species, and through the multi-path reaction mechanism of spontaneous oxidation of pollutants and degradation by reactive oxygen species, achieve efficient removal of chemical oxygen demand (COD) in sewage.

[0057] Figure 1 is a physical picture of EPOA-4-1 prepared in Example 1. The pore channels of EPOA-4-1 are evenly distributed, with large pore diameters, high porosity, and the internal pores are interconnected, which helps to improve the fluidity of sewage. The active sites are extremely exposed on the surface, increasing the contact area with pollutants and DO in the water.

[0058] Figure 2 is a graph showing the degradation of COD in pharmaceutical wastewater by EPOA-4-1 prepared in Example 1 according to Example 4. The results show that: after only 4 hours of short-term treatment, the COD value of high-concentration pharmaceutical wastewater has obvious removal, and the maximum COD removal can reach 1700 mg / L. After cyclic treatment for more than 42 days without adding any chemicals, EPOA-4-1 still maintains high-efficient water purification effect, fully proving the excellent water purification performance and stability of EPOA-4-1.

[0059] Figure 3 is a schematic diagram of the purification mechanism of the EPOA-4 material in the water treatment process. The active sites in the internal and external voids of the EPOA-4 material capture pollutants and DO in the water. The pollutants lose electrons and are oxidized into small-molecule substances, and the electrons are transferred to DO through multi-functional channels to generate reactive oxygen species such as hydroxyl radicals, superoxide radicals, and singlet oxygen, which synergistically attack the pollutants to achieve the synergistic effect of reducing pollution and carbon emissions in the sewage purification process.

[0060] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A preparation method of a green, low-carbon, highly efficient and durable EPOA-4 material, characterized in that, The steps include: S1: After mixing powdered alumina and water in a mass ratio of 15:10, silica sol, binder, dispersant, thickener and water are added in sequence, the mixture is ball-milled, and a few drops of defoamer are added to form a slurry I with a solute ratio of 55-60%wt; S2: After washing the polyurethane foam with clean water for several times, immerse it in a 10~20%wt alkaline solution, maintain the solution temperature at 55~65℃, keep it for 2~4 hours, and then dry it to perform surface roughening modification for slurry hanging; S3: The pretreated polyurethane foam is immersed in slurry I, taken out after slurrying, and excess slurry I is shaken off. After natural air drying at room temperature for 12 to 24 hours, it is placed in an oven for drying for 12 to 18 hours to obtain a foamed alumina body, which is then placed in a muffle furnace and maintained at 500 to 600° C. for 1 to 2 hours, followed by insulation at 1300 to 1500° C. for 2 to 4 hours. After the furnace is naturally cooled, foamed alumina is obtained; S4: Inorganic aluminum salt and water are mixed in a mass ratio of 0.7:10, and the mixture is stirred at a temperature above 80°C for 30-90 minutes, and then an acidic solution is slowly added to make the molar ratio of Al3+:H+ in the solution (10-15):10, and the mixture is stirred in a high temperature water bath for 4-6 hours and then cooled to room temperature to obtain slurry II; S5: immersing the foamed aluminum oxide prepared above in slurry II, then taking out and shaking off excess slurry II, placing in an oven to dry for 1-3 hours, and then placing in a muffle furnace at 500-600° C. for 2-4 hours to obtain an EPOA-4 precursor; S6: Dissolve the iron salt in water to form an impregnation solution and add the EPOA-4 precursor, keeping the mass ratio of Fe3+ to EPOA-4 precursor at (0.5-3):

10. After sufficient reaction, take out and place in an oven to dry for 1~3 hours, then place in a muffle furnace at 400~550℃ for 2~4 hours, and after natural cooling, obtain EPOA-4.

2. The preparation method according to claim 1, characterized in that, In step S1, the adhesive includes polyvinyl alcohol, polytetrafluoroethylene and polyvinylidene fluoride, etc., the dispersant includes polyacrylamide, sodium hexametaphosphate and sodium dodecyl sulfate, etc., the thickener includes sodium carboxymethyl cellulose, β-cyclodextrin and starch, etc., and the defoamer is n-butanol.

3. The preparation method according to claim 1, characterized in that, The mass ratio of silica sol, binder, dispersant, thickener and water added in step S1 is (8-9): (2-3): (0.1-0.2): (0.5-0.8):

10.

4. The preparation method according to claim 1, characterized in that, The alkaline reagent in step S2 includes but is not limited to sodium hydroxide, sodium hydrogen phosphate, ammonia water, etc.

5. The preparation method according to claim 1, characterized in that, In step S3, the oven temperature is 60-80° C., and the heating rate of the muffle furnace is controlled at 1-5° C. / min.

6. The preparation method according to claim 1, characterized in that, The inorganic aluminum salt in step S4 includes but is not limited to pseudo-boehmite, sodium aluminate and potassium aluminate, and the acidic solution includes but is not limited to acetic acid, sulfuric acid and nitric acid.

7. The preparation method according to claim 1, characterized in that, The oven temperature described in step S5 is 80~120 °C, and the heating rate of the muffle furnace is controlled at 5~10 °C per minute.

8. The preparation method according to claim 1, characterized in that, The iron salts described in step S6 include, but are not limited to, iron chloride, iron nitrate, iron sulfate, etc., either alone or in combination. The oven temperature is 80~100 °C, and the heating rate of the muffle furnace is controlled at 5~10 °C per minute.

9. An EPOA-4 material prepared by the method according to any one of claims 1 to 8.

10. Use of the EPOA-4 material according to claim 9 in water treatment.

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