Preparation method of porous geopolymer and application thereof in degrading organic matters

Abstract

The application discloses a porous geopolymer preparation method and application thereof in degradation of organic matters, and the porous geopolymer material is formed by mixing iron tailings, steel slag, red mud, alkali activator, foaming agent, foam stabilizer and water reducing agent, and the porous geopolymer is successfully prepared by modifying and utilizing the industrial waste iron tailings, steel slag and red mud, the prepared geopolymer has rich pore structure and can provide more photocatalytic active sites; the geopolymer can improve the removal effect of organic matters in water, reduce the treatment cost of organic matters and realize secondary utilization of waste resources; the geopolymer effectively solves the problems of tailing accumulation and environmental pollution, provides favorable conditions for realizing high-value utilization of industrial solid wastes, and has a good application prospect.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, specifically to a method for preparing porous geopolymers and their application in the degradation of organic matter. Background Technology

[0002] In the ever-evolving social and economic environment, water pollution caused by a class of organic compounds, represented by tetracycline antibiotics, has become an urgent problem. Tetracycline is a broad-spectrum antibacterial agent widely used in human medicine and veterinary medicine, and also widely used as an agricultural feed additive. Due to its low metabolic degradation rate, widespread use leads to frequent release of tetracycline into the environment, causing varying degrees of pollution to soil and water bodies. Furthermore, due to its chemical stability, tetracycline is difficult to degrade in the natural environment. The accumulation of tetracycline in the food chain may have harmful effects on the human endocrine and central nervous systems, raising widespread concern.

[0003] Given these problems, there is an urgent need to research other effective methods to mitigate the adverse environmental impacts of tetracycline. Developing economically feasible technologies to remove tetracycline from the environment is of paramount importance. Currently, methods for treating antibiotic-containing organic wastewater include adsorption, biodegradation, electrochemical technologies, advanced oxidation processes (AOPs), and photocatalysis. However, adsorption, as a phase change method, cannot completely solve the problem of organic pollution. While biodegradation has potential benefits, it also presents some potential problems due to the possible generation of bioactive and toxic substances. Electrochemical methods face certain limitations in effectively transferring organic matter to the electrode surface. Patent CN108998439A uses microorganisms immobilized in gel spheres to remove tetracycline from water, but the gel carrier inevitably generates some mass transfer resistance, affecting the transport efficiency of the matrix.

[0004] Therefore, photocatalysis is considered the optimal method for tetracycline treatment due to its high efficiency, cost-effectiveness, and minimal environmental impact. Advanced oxidation processes (AORs) utilize catalysts and electro-optical radiation to generate hydroxyl radicals and sulfate ions through activation with persulfate or peroxymonosulfate (PMS). These processes involve addition, substitution, electron transfer, and other interactions between free radicals and organic matter. Peroxymonosulfate has attracted widespread attention due to its stability, solubility, and strong redox capabilities, and can effectively degrade various organic pollutants such as azo dyes, phenolic compounds, and antibiotics.

[0005] Studies have shown that transition metals such as cobalt, iron, and copper promote the activation of PMS, enhancing its catalytic activity. However, using transition metals to activate PMS has some drawbacks, including increased cost and potential secondary pollution. Therefore, in recent years, researchers have begun to focus on non-metallic catalysts or catalysts with high cost-effectiveness. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a method for preparing porous geopolymers and their application in the degradation of organic matter. This porous geopolymer material is composed of iron tailings, steel slag, red mud, alkali activator, foaming agent, foam stabilizer, and water-reducing agent. By modifying and utilizing industrial waste iron tailings, steel slag, and red mud, a geopolymer with a porous structure is successfully prepared. The prepared geopolymer possesses a rich pore structure, providing more photocatalytic active sites. It can improve the removal efficiency of organic matter in water while reducing the cost of organic matter treatment and realizing the secondary utilization of waste resources. It effectively solves the problems of tailings accumulation and environmental pollution, providing favorable conditions for the high-value-added utilization of industrial solid waste and has good application prospects.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] A porous geopolymer comprising the following raw materials:

[0009] Solid powder: iron tailings, steel slag, and red mud; wherein, the mass fraction of iron tailings in the solid powder is 70%; the mass fraction of steel slag is 5%-25%; the mass fraction of red mud is 25%-5%; and the sum of the mass fractions of the three is 100%.

[0010] Alkali activator: water glass and calcium carbide slag, wherein the mass ratio of water glass to calcium carbide slag is 1-4:4-1; the mass ratio of water glass to solid powder is 1-4:10; the mass ratio of calcium carbide slag to solid powder is 1-4:10.

[0011] Foaming agent: hydrogen peroxide solution and 1,3-disulfonylhydrazidebenzene, wherein the mass ratio of hydrogen peroxide solution to 1,3-disulfonylhydrazidebenzene is 0.1-1.0:0.1-1.0; the mass ratio of hydrogen peroxide solution to solid powder is 0.1-1.0:100; the mass ratio of 1,3-disulfonylhydrazidebenzene to solid powder is 0.1-1.0:100.

[0012] Foam stabilizer: The mass ratio of the foam stabilizer to the solid powder is 0.8-1.0:100;

[0013] Water-reducing agent: The mass ratio of the foam stabilizer to the solid powder is 0.55-0.80:100;

[0014] The foam stabilizer is sodium dodecyl sulfate (SDS).

[0015] The water-reducing agent is a polycarboxylate-based high-efficiency water-reducing agent.

[0016] Furthermore, the mass percentages of each component in the iron tailings are as follows: SiO2 30%-50%, Al2O3 10%-20%, Fe2O3 20%-30%, CaO 5%-10%, MgO 1%-3%, K2O 1%-3%, Na2O 1%-3%, TiO2 1%-2%, MnO 0.1%-0.5%, and its loss on ignition is 0.4%-1%.

[0017] Furthermore, the iron tailings have a particle size of less than 0.070 mm and need to be calcined at 300℃-700℃ for 1-3 hours before use; the steel slag has a particle size of less than 0.070 mm and the red mud has a particle size of less than 0.085 mm and need to be dried at 60℃-100℃ to constant weight before use.

[0018] Furthermore, the water glass has a modulus of 3.3, a solid content of 34 wt%, and a Baumé degree of 40; the concentration of the foaming agent hydrogen peroxide solution is 10 wt%-30 wt%.

[0019] A method for preparing porous geopolymers specifically includes the following steps:

[0020] Step S1: Mix iron tailings, steel slag and red mud evenly in proportion to obtain solid mixture A;

[0021] Step S2: Water glass and calcium carbide slag are mixed in proportion, stirred and mixed evenly, and then left to stand for a period of time to obtain an alkaline activator;

[0022] Step S3: Hydrogen peroxide solution and 1,3-disulfonylhydrazide are mixed in a certain proportion, stirred and mixed evenly, and then left to stand for a period of time to obtain a foaming agent;

[0023] Step S4: Add the solid mixture A obtained in step S1 to the alkali activator obtained in step S2; after mixing, mechanically stir to obtain a slurry B;

[0024] Step S5: Add the foaming agent obtained in step S3 to the mixed slurry B obtained in step S4, and then mechanically stir to obtain mixed slurry C.

[0025] Step S6: Pour the mixed slurry C into the mold and continuously vibrate to remove air from the slurry;

[0026] Step S7: Seal the sample together with the mold, cure it at room temperature and in an oven, and cure it at room temperature after demolding.

[0027] Furthermore, the room temperature curing temperature is 24-28℃, the curing time is 12-48 hours, the oven curing temperature is 80-150℃, the curing time is 8-12 hours, followed by room temperature curing for 7-14 days.

[0028] The above-mentioned porous geopolymers are used in the degradation of organic matter, and the application methods include:

[0029] The porous geopolymer was mixed with organic wastewater and then potassium persulfate PMS was added. The mixture was stirred in the dark to reach adsorption-desorption equilibrium, and stirring was carried out simultaneously under xenon lamp illumination.

[0030] The organic compound is tetracycline.

[0031] Furthermore, the stirring time in the dark is 30-60 minutes.

[0032] Furthermore, the organic matter solution concentration is 10-100 mg / L, the pH value is 2-7, and the ultraviolet spectral peak is 265-275 nm.

[0033] Furthermore, the amount of potassium peroxymonosulfate PMS added is 50-300 mg / L, the xenon lamp light source intensity is 70-80 cd, the illumination time is 30-60 min, and the stirring rate is 800-1000 r / min.

[0034] The beneficial effects of this invention are as follows:

[0035] (1) By modifying and utilizing industrial waste iron tailings, steel slag and red mud, a geopolymer with a porous structure was successfully prepared and used for photocatalytic degradation of organic matter;

[0036] (2) The components of this invention work synergistically, and the prepared geopolymer has a rich porous structure, which can provide more photocatalytic active sites;

[0037] (3) By adopting a wide range of raw material sources and implementing green and environmentally friendly preparation processes, there is no CO2 emission, which reduces production costs and effectively solves the problems of tailings accumulation and environmental pollution, providing favorable conditions for the high-value-added utilization of industrial solid waste. Attached Figure Description

[0038] Figure 1 The EDS spectrum of the geopolymer prepared in Example 10 of this invention;

[0039] Figure 2 This is a scanning electron microscope image of the geopolymer prepared in Example 10 of the present invention. Detailed Implementation

[0040] The optimized embodiments of the present invention will now be described in more detail. While optimized embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art. The scope of protection of the present invention includes, but is not limited to, the following:

[0041] In the following examples, the mass percentages of the geopolymer porous material components are as follows: iron tailings: steel slag: red mud 70%: 5%-25%: 25%-5%. Water glass is a commercially available chemical agent; its modulus is 3.3, solid content is 34wt%, Baumé degree is 40, and the amount of water glass added is 10wt%-40wt% of the solid powder; the amount of calcium carbide slag added is 40wt%-10wt% of the solid powder. The hydrogen peroxide used was of analytical grade with a content of 30%, and the addition amount was 0.1wt%-1.0wt% of the solid powder. The addition amount of 1,3-disulfonylhydrazidebenzene was 1.0wt%-0.1wt% of the solid powder. The addition amount of SDS was 0.8wt%-1.0wt% of the solid powder. The addition amount of water-reducing agent was 0.55wt%-0.80wt% of the solid powder. The curing time was 24 hours at room temperature, 8 hours at 150℃ in an oven, and then 7 days at room temperature.

[0042] The water used in the following examples is tap water.

[0043] In this embodiment of the invention, the concentration of the organic compound (tetracycline) was determined by measuring the absorption peak intensity at 356 nm using a UV spectrophotometer.

[0044] Example 1

[0045] The porous geopolymer of this embodiment includes iron tailings, steel slag, red mud, alkali activator, water-reducing agent, foaming agent, and foam stabilizer. The iron tailings account for 70% (70g) of the solid powder, while the steel slag and red mud account for 5% (5g) and 25% (25g) of the solid powder, respectively. The water glass modulus of the alkali activator is 3.3, and the amount added is 25wt% (25g) of the solid powder. The amount of calcium carbide slag added is also 25wt% (25g) of the solid powder. The amount of water-reducing agent added is 0.55wt% (0.55g) of the solid powder. The amount of hydrogen peroxide solution added to the foaming agent is 0.1wt% (0.1g) of the solid powder, the amount of 1,3-disulfonylhydrazidebenzene added is 1wt% (1g) of the solid powder, and the amount of SDS added is 0.8wt% (0.8g) of the solid powder.

[0046] After mixing iron tailings, steel slag and red mud evenly according to the above proportions, water glass and calcium carbide slag are added in proportion. After mechanically stirring evenly, polycarboxylate superplasticizer, foaming agent and SDS are added. Then the mixture is poured into a mold and cured at room temperature of 25℃ for 24 hours, then cured at 150℃ in an oven for 8 hours, and then cured at room temperature for 7 days.

[0047] Using a 100ml, 50mg / L, 25℃ organic (tetracycline) solution as the target pollutant, 100mg of geopolymer and 5mg of PMS were added to the solution. The mixture was stirred in the dark for 30 minutes to reach adsorption-desorption equilibrium. A xenon lamp was turned on and the solution was irradiated at a distance of about 15cm from the mouth of the beaker for 30 minutes. Samples were taken every 5 minutes and detected using a UV spectrophotometer.

[0048] Example 2

[0049] The porous geopolymer of this embodiment includes iron tailings, steel slag, red mud, alkali activator, water-reducing agent, foaming agent, and foam stabilizer. The iron tailings account for 70% (70g) of the solid powder, while the steel slag and red mud account for 5% (5g) and 25% (25g) of the solid powder, respectively. The water glass modulus of the alkali activator is 3.3, and the amount added is 10wt% (10g) of the solid powder. The amount of calcium carbide slag added is 40wt% (40g) of the solid powder. The amount of water-reducing agent added is 0.55wt% (0.55g) of the solid powder. The amount of hydrogen peroxide solution added to the foaming agent is 1wt% (1g) of the solid powder, and the amount of 1,3-disulfonylhydrazidebenzene added is 0.1wt% (0.1g) of the solid powder. The amount of foam stabilizer added is 0.8wt% of the solid powder.

[0050] After mixing iron tailings, steel slag and red mud evenly according to the above proportions, water glass and calcium carbide slag are added in proportion. After mechanically stirring evenly, polycarboxylate superplasticizer, foaming agent and SDS are added. Then the mixture is poured into a mold and cured at room temperature of 25℃ for 24 hours, then cured at 150℃ in an oven for 8 hours, and then cured at room temperature for 7 days.

[0051] Using a 100ml, 50mg / L, 25℃ organic (tetracycline) solution as the target pollutant, 100mg of geopolymer and 5mg of PMS were added to the solution. The mixture was stirred in the dark for 30 minutes to reach adsorption-desorption equilibrium. A xenon lamp was turned on and the solution was irradiated at a distance of about 15cm from the mouth of the beaker for 30 minutes. Samples were taken every 5 minutes and detected using a UV spectrophotometer.

[0052] Example 3

[0053] The porous geopolymer of this embodiment includes iron tailings, steel slag, red mud, alkali activator, water-reducing agent, foaming agent, and foam stabilizer. The iron tailings account for 70% (70g) of the solid powder, while the steel slag and red mud account for 5% (5g) and 25% (25g) of the solid powder, respectively. The water glass modulus of the alkali activator is 3.3, and the amount added is 40wt% (40g) of the solid powder. The amount of calcium carbide slag added is 10wt% (10g) of the solid powder. The amount of water-reducing agent added is 0.55wt% (0.55g) of the solid powder. The amount of hydrogen peroxide solution added to the foaming agent is 0.1wt% (0.1g) of the solid powder, and the amount of 1,3-disulfonylhydrazidebenzene added is 1wt% (1g) of the solid powder. The amount of foam stabilizer added is 1.0wt% (1.0g) of the solid powder.

[0054] After mixing iron tailings, steel slag and red mud evenly according to the above proportions, water glass and calcium carbide slag are added in proportion. After mechanically stirring evenly, polycarboxylate superplasticizer, foaming agent and SDS are added. Then the mixture is poured into a mold and cured at room temperature of 25℃ for 24 hours, then cured at 150℃ in an oven for 8 hours, and then cured at room temperature for 7 days.

[0055] Using a 100ml, 200mg / L, 25℃ organic (tetracycline) solution as the target pollutant, 100mg of geopolymer and 5mg of PMS were added to the solution. The mixture was stirred in the dark for 30 minutes to reach adsorption-desorption equilibrium. A xenon lamp was turned on and the solution was irradiated at a distance of about 15cm from the mouth of the beaker for 30 minutes. Samples were taken every 5 minutes and detected using a UV spectrophotometer.

[0056] Example 4

[0057] The porous geopolymer of this embodiment includes iron tailings, steel slag, red mud, alkali activator, water-reducing agent, foaming agent, and foam stabilizer. The mass fraction of iron tailings in the solid powder is 70% (70g), and the mass fractions of steel slag and red mud are 15% (15g) and 15% (15g) respectively. The water glass modulus of the alkali activator is 3.3, and the amount added is 25wt% (25g) of the solid powder. The amount of calcium carbide slag added is 25wt% (25g) of the solid powder. The amount of water-reducing agent added is 0.8wt% (0.8g) of the solid powder. The amount of hydrogen peroxide solution added in the foaming agent is 1wt% (1g) of the solid powder, and the amount of 1,3-disulfonylhydrazidebenzene added is 0.1wt% (0.1g) of the solid powder. The amount of foam stabilizer added is 0.8wt% (0.8g) of the solid powder.

[0058] After mixing iron tailings, steel slag and red mud evenly according to the above proportions, water glass and calcium carbide slag are added in proportion. After mechanically stirring evenly, polycarboxylate superplasticizer, foaming agent and SDS are added. Then the mixture is poured into a mold and cured at room temperature of 25℃ for 24 hours, then cured at 150℃ in an oven for 8 hours, and then cured at room temperature for 7 days.

[0059] Using a 100ml, 50mg / L, 25℃ organic (tetracycline) solution as the target pollutant, 100mg of geopolymer and 5mg of PMS were added to the solution. The mixture was stirred in the dark for 30 minutes to reach adsorption-desorption equilibrium. A xenon lamp was turned on and the solution was irradiated at a distance of about 15cm from the mouth of the beaker for 30 minutes. Samples were taken every 5 minutes and detected using a UV spectrophotometer.

[0060] Example 5

[0061] The porous geopolymer of this embodiment includes iron tailings, steel slag, red mud, alkali activator, water-reducing agent, foaming agent, and foam stabilizer. The mass fraction of iron tailings in the solid powder is 70% (70g), and the mass fractions of steel slag and red mud are 15% (15g) and 15% (15g) respectively. The water glass modulus of the alkali activator is 3.3, and the amount added is 10wt% (10g) of the solid powder. The amount added of calcium carbide slag is 40wt% (40g) of the solid powder. The amount added of water-reducing agent is 0.55wt% (0.55g) of the solid powder. The amount added of hydrogen peroxide solution in the foaming agent is 0.1wt% (0.1g) of the solid powder, and the amount added of 1,3-disulfonylhydrazidebenzene is 1wt% (1g) of the solid powder. The amount added of foam stabilizer is 0.8wt% (0.8g) of the solid powder.

[0062] After mixing iron tailings, steel slag and red mud evenly according to the above proportions, water glass and calcium carbide slag are added in proportion. After mechanically stirring evenly, polycarboxylate superplasticizer, foaming agent and SDS are added. Then the mixture is poured into a mold and cured at room temperature of 25℃ for 24 hours, then cured at 150℃ in an oven for 8 hours, and then cured at room temperature for 7 days.

[0063] Using a 100ml, 300mg / L, 25℃ organic (tetracycline) solution as the target pollutant, 100mg of geopolymer and 5mg of PMS were weighed and added to the solution. The mixture was stirred in the dark for 30 minutes to reach adsorption-desorption equilibrium. A xenon lamp was turned on and the solution was irradiated at a distance of about 15cm from the mouth of the beaker for 30 minutes. Samples were taken every 5 minutes and detected using a UV spectrophotometer.

[0064] Example 6

[0065] The porous geopolymer of this embodiment includes iron tailings, steel slag, red mud, alkali activator, water-reducing agent, foaming agent, and foam stabilizer. The iron tailings account for 70% (70g) of the solid powder, and the steel slag and red mud account for 15% (15g) and 15% (15g) of the solid powder, respectively. The water glass modulus of the alkali activator is 3.3, and the amount added is 10wt% (10g) of the solid powder. The amount of calcium carbide slag added is 40wt% (40g) of the solid powder. The amount of water-reducing agent added is 0.55wt% (0.55g) of the solid powder. The amount of hydrogen peroxide solution added to the foaming agent is 1wt% (1g) of the solid powder, and the amount of 1,3-disulfonylhydrazidebenzene added is 0.1wt% (0.1g) of the solid powder. The amount of foam stabilizer added is 0.8wt% (0.8g) of the solid powder.

[0066] After mixing iron tailings, steel slag and red mud evenly according to the above proportions, water glass and calcium carbide slag are added in proportion. After mechanically stirring evenly, polycarboxylate superplasticizer, foaming agent and SDS are added. Then the mixture is poured into a mold and cured at room temperature of 25℃ for 24 hours, then cured at 150℃ in an oven for 8 hours, and then cured at room temperature for 7 days.

[0067] Using a 100ml, 50mg / L, 25℃ organic (tetracycline) solution as the target pollutant, 100mg of geopolymer and 5mg of PMS were added to the solution. The mixture was stirred in the dark for 30 minutes to reach adsorption-desorption equilibrium. A xenon lamp was turned on and the solution was irradiated at a distance of about 15cm from the mouth of the beaker for 30 minutes. Samples were taken every 5 minutes and detected using a UV spectrophotometer.

[0068] Example 7

[0069] The porous geopolymer of this embodiment includes iron tailings, steel slag, red mud, alkali activator, water-reducing agent, foaming agent, and foam stabilizer. The iron tailings account for 70% (70g) of the solid powder, while the steel slag and red mud account for 25% (25g) and 5% (5g) of the solid powder, respectively. The water glass modulus of the alkali activator is 3.3, and the amount added is 25wt% (25g) of the solid powder. The amount of calcium carbide slag added is also 25wt% (25g) of the solid powder. The amount of water-reducing agent added is 0.55wt% (0.55g) of the solid powder. The amount of hydrogen peroxide solution added to the foaming agent is 1wt% (1g) of the solid powder, and the amount of 1,3-disulfonylhydrazidebenzene added is 0.1wt% (0.1g) of the solid powder. The amount of foam stabilizer added is 0.8wt% (0.8g) of the solid powder.

[0070] After mixing iron tailings, steel slag and red mud evenly according to the above proportions, water glass and calcium carbide slag are added in proportion. After mechanically stirring evenly, polycarboxylate superplasticizer, foaming agent and SDS are added. Then the mixture is poured into a mold and cured at room temperature of 25℃ for 24 hours, then cured at 150℃ in an oven for 8 hours, and then cured at room temperature for 7 days.

[0071] Using a 100ml, 50mg / L, 25℃ organic (tetracycline) solution as the target pollutant, 100mg of geopolymer and 5mg of PMS were added to the solution. The mixture was stirred in the dark for 30 minutes to reach adsorption-desorption equilibrium. A xenon lamp was turned on and the solution was irradiated at a distance of about 15cm from the mouth of the beaker for 30 minutes. Samples were taken every 5 minutes and detected using a UV spectrophotometer.

[0072] Example 8

[0073] The porous geopolymer of this embodiment includes iron tailings, steel slag, red mud, alkali activator, water-reducing agent, foaming agent, and foam stabilizer. The iron tailings account for 70% (70g) of the solid powder, while the steel slag and red mud account for 25% (25g) and 5% (5g) of the solid powder, respectively. The water glass modulus of the alkali activator is 3.3, and the amount added is 10wt% (10g) of the solid powder. The amount of calcium carbide slag added is 40wt% (40g) of the solid powder. The amount of water-reducing agent added is 0.55wt% (0.55g) of the solid powder. The amount of hydrogen peroxide solution added to the foaming agent is 0.1wt% (0.1g) of the solid powder, and the amount of 1,3-disulfonylhydrazidebenzene added is 1wt% (1g) of the solid powder. The amount of foam stabilizer added is 0.8wt% (0.8g) of the solid powder.

[0074] After mixing iron tailings, steel slag and red mud evenly according to the above proportions, water glass and calcium carbide slag are added in proportion. After mechanically stirring evenly, polycarboxylate superplasticizer, foaming agent and SDS are added. Then the mixture is poured into a mold and cured at room temperature of 25℃ for 24 hours, then cured at 150℃ in an oven for 8 hours, and then cured at room temperature for 7 days.

[0075] Using a 100ml, 300mg / L, 25℃ organic (tetracycline) solution as the target pollutant, 100mg of geopolymer and 5mg of PMS were weighed and added to the solution. The mixture was stirred in the dark for 30 minutes to reach adsorption-desorption equilibrium. A xenon lamp was turned on and the solution was irradiated at a distance of about 15cm from the mouth of the beaker for 30 minutes. Samples were taken every 5 minutes and detected using a UV spectrophotometer.

[0076] Example 9

[0077] The porous geopolymer of this embodiment includes iron tailings, steel slag, red mud, alkali activator, water-reducing agent, foaming agent, and foam stabilizer. The iron tailings account for 70% (70g) of the solid powder, while the steel slag and red mud account for 25% (25g) and 5% (5g) of the solid powder, respectively. The water glass modulus of the alkali activator is 3.3, and the amount added is 40wt% (40g) of the solid powder. The amount of calcium carbide slag added is 10wt% (10g) of the solid powder. The amount of water-reducing agent added is 0.55wt% (0.55g) of the solid powder. The amount of hydrogen peroxide solution added to the foaming agent is 1wt% (1g) of the solid powder, and the amount of 1,3-disulfonylhydrazidebenzene added is 0.1wt% (0.1g) of the solid powder. The amount of foam stabilizer added is 0.8wt% (0.8g) of the solid powder.

[0078] After mixing iron tailings, steel slag and red mud evenly according to the above proportions, water glass and calcium carbide slag are added in proportion. After mechanically stirring evenly, polycarboxylate superplasticizer, foaming agent and SDS are added. Then the mixture is poured into a mold and cured at room temperature of 25℃ for 24 hours, then cured at 150℃ in an oven for 8 hours, and then cured at room temperature for 7 days.

[0079] Using a 100ml, 50mg / L, 25℃ organic (tetracycline) solution as the target pollutant, 100mg of geopolymer and 5mg of PMS were added to the solution. The mixture was stirred in the dark for 30 minutes to reach adsorption-desorption equilibrium. A xenon lamp was turned on and the solution was irradiated at a distance of about 15cm from the mouth of the beaker for 30 minutes. Samples were taken every 5 minutes and detected using a UV spectrophotometer.

[0080] Example 10

[0081] The porous geopolymer of this embodiment includes iron tailings, steel slag, red mud, alkali activator, water-reducing agent, foaming agent, and foam stabilizer. The iron tailings account for 70% (70g) of the solid powder, while the steel slag and red mud account for 25% (25g) and 5% (5g) of the solid powder, respectively. The water glass modulus of the alkali activator is 3.3, and the amount added is 40wt% (40g) of the solid powder. The amount of calcium carbide slag added is 10wt% (10g) of the solid powder. The amount of water-reducing agent added is 0.55wt% (0.55g) of the solid powder. The amount of hydrogen peroxide solution added to the foaming agent is 0.1wt% (0.1g) of the solid powder, and the amount of 1,3-disulfonylhydrazidebenzene added is 1wt% (1g) of the solid powder. The amount of foam stabilizer added is 0.8wt% (0.8g) of the solid powder.

[0082] After mixing iron tailings, steel slag and red mud evenly according to the above proportions, water glass and calcium carbide slag are added in proportion. After mechanically stirring evenly, polycarboxylate superplasticizer, foaming agent and SDS are added. Then the mixture is poured into a mold and cured at room temperature of 25℃ for 24 hours, then cured at 150℃ in an oven for 8 hours, and then cured at room temperature for 7 days.

[0083] Using a 100ml, 50mg / L, 25℃ organic (tetracycline) solution as the target pollutant, 100mg of geopolymer and 5mg of PMS were added to the solution. The mixture was stirred in the dark for 30 minutes to reach adsorption-desorption equilibrium. A xenon lamp was turned on and the solution was irradiated at a distance of about 15cm from the mouth of the beaker for 30 minutes. Samples were taken every 5 minutes and detected using a UV spectrophotometer.

[0084] Figure 1 The image shows the EDS energy spectrum of the porous geopolymer prepared in Example 10 of this invention. The Fe content in the EDS energy spectrum is 11.61%, and the iron element is uniformly and widely distributed on the surface of the geopolymer, which can provide sufficient sites for the reaction.

[0085] The degradation effect of organic matter (tetracycline) in Examples 1-10 was tested, and the results are shown in Table 1.

[0086] Table 1. Degradation effect of organic matter (tetracycline) in the examples

[0087]

[0088] Based on Example 10, the following comparative example is set:

[0089] Comparative Example 1

[0090] The porous geopolymer in this comparative example includes iron tailings, steel slag, red mud, alkali activator, water-reducing agent, foaming agent, and foam stabilizer. The mass fraction of iron tailings in the solid powder is 70% (70g), and the mass fractions of steel slag and red mud are 30% (30g) and 0% (0g), respectively. The water glass modulus of the alkali activator is 3.3, and the amount added is 40wt% (40g) of the solid powder. The amount added of calcium carbide slag is 10wt% (10g) of the solid powder. The amount added of water-reducing agent is 0.55wt% (0.55g) of the solid powder. The amount added of hydrogen peroxide solution in the foaming agent is 0.1wt% (0.1g) of the solid powder, and the amount added of 1,3-disulfonyl hydrazine with benzene is 1wt% (1g) of the solid powder. The amount added of foam stabilizer is 0.8wt% (0.8g) of the solid powder.

[0091] After mixing iron tailings, steel slag and red mud evenly according to the above proportions, water glass and calcium carbide slag are added in proportion. After mechanically stirring evenly, polycarboxylate superplasticizer, foaming agent and SDS are added. Then the mixture is poured into a mold and cured at room temperature of 25℃ for 24 hours, then cured at 150℃ in an oven for 8 hours, and then cured at room temperature for 7 days.

[0092] Using a 100ml, 50mg / L, 25℃ organic (tetracycline) solution as the target pollutant, 100mg of geopolymer and 5mg of PMS were added to the solution. The mixture was stirred in the dark for 30 minutes to reach adsorption-desorption equilibrium. A xenon lamp was turned on and the solution was irradiated at a distance of about 15cm from the mouth of the beaker for 30 minutes. Samples were taken every 5 minutes and detected using a UV spectrophotometer.

[0093] Comparative Example 2

[0094] The porous geopolymer in this comparative example includes iron tailings, steel slag, red mud, alkali activator, water-reducing agent, foaming agent, and foam stabilizer. The mass fraction of iron tailings in the solid powder is 70% (70g), and the mass fractions of steel slag and red mud are 0% (0g) and 30% (30g), respectively. The water glass modulus of the alkali activator is 3.3, and the amount added is 40wt% (40g) of the solid powder. The amount added of calcium carbide slag is 10wt% (10g) of the solid powder. The amount added of water-reducing agent is 0.55wt% (0.55g) of the solid powder. The amount added of hydrogen peroxide solution in the foaming agent is 0.1wt% (0.1g) of the solid powder, and the amount added of 1,3-disulfonylhydrazidebenzene is 1wt% (1g) of the solid powder. The amount added of foam stabilizer is 0.8wt% (0.8g) of the solid powder.

[0095] After mixing iron tailings, steel slag and red mud evenly according to the above proportions, water glass and calcium carbide slag are added in proportion. After mechanically stirring evenly, polycarboxylate superplasticizer, foaming agent and SDS are added. Then the mixture is poured into a mold and cured at room temperature of 25℃ for 24 hours, then cured at 150℃ in an oven for 8 hours, and then cured at room temperature for 7 days.

[0096] Using a 100ml, 50mg / L, 25℃ organic (tetracycline) solution as the target pollutant, 100mg of geopolymer and 5mg of PMS were added to the solution. The mixture was stirred in the dark for 30 minutes to reach adsorption-desorption equilibrium. A xenon lamp was turned on and the solution was irradiated at a distance of about 15cm from the mouth of the beaker for 30 minutes. Samples were taken every 5 minutes and detected using a UV spectrophotometer.

[0097] Comparative Example 3

[0098] The porous geopolymer in this comparative example includes iron tailings, steel slag, red mud, alkali activator, water-reducing agent, foaming agent, and foam stabilizer. The mass fraction of iron tailings in the solid powder is 70% (70g), and the mass fractions of steel slag and red mud are 25% (25g) and 5% (5g), respectively. The water glass modulus of the alkali activator is 3.3, and the amount added is 0 wt% (0g) of the solid powder. The amount added of calcium carbide slag is 50 wt% (50g) of the solid powder. The amount added of water-reducing agent is 0.55 wt% (0.55g) of the solid powder. The amount added of hydrogen peroxide solution in the foaming agent is 0.1 wt% (0.1g) of the solid powder, and the amount added of 1,3-disulfonylhydrazidebenzene is 1 wt% (1g) of the solid powder. The amount added of foam stabilizer is 0.8 wt% (0.8g) of the solid powder.

[0099] After mixing iron tailings, steel slag and red mud evenly according to the above proportions, water glass and calcium carbide slag are added in proportion. After mechanically stirring evenly, polycarboxylate superplasticizer, foaming agent and SDS are added. Then the mixture is poured into a mold and cured at room temperature of 25℃ for 24 hours, then cured at 150℃ in an oven for 8 hours, and then cured at room temperature for 7 days.

[0100] Using a 100ml, 50mg / L, 25℃ organic (tetracycline) solution as the target pollutant, 100mg of geopolymer and 5mg of PMS were added to the solution. The mixture was stirred in the dark for 30 minutes to reach adsorption-desorption equilibrium. A xenon lamp was turned on and the solution was irradiated at a distance of about 15cm from the mouth of the beaker for 30 minutes. Samples were taken every 5 minutes and detected using a UV spectrophotometer.

[0101] Comparative Example 4

[0102] The porous geopolymer in this comparative example includes iron tailings, steel slag, red mud, alkali activator, water-reducing agent, foaming agent, and foam stabilizer. The mass fraction of iron tailings in the solid powder is 70% (70g), and the mass fractions of steel slag and red mud are 25% (25g) and 5% (5g), respectively. The water glass modulus of the alkali activator is 3.3, and the amount added is 50wt% (50g) of the solid powder, while the amount added of calcium carbide slag is 0wt% (0g) of the solid powder. The amount added of the water-reducing agent is 0.55wt% (0.55g) of the solid powder. The amount added of hydrogen peroxide solution in the foaming agent is 0.1wt% (0.1g) of the solid powder, and the amount added of 1,3-disulfonylhydrazidebenzene is 1wt% (1g) of the solid powder. The amount added of the foam stabilizer is 0.8wt% (0.8g) of the solid powder.

[0103] After mixing iron tailings, steel slag and red mud evenly according to the above proportions, water glass and calcium carbide slag are added in proportion. After mechanically stirring evenly, polycarboxylate superplasticizer, foaming agent and SDS are added. Then the mixture is poured into a mold and cured at room temperature of 25℃ for 24 hours, then cured at 150℃ in an oven for 8 hours, and then cured at room temperature for 7 days.

[0104] Using a 100ml, 50mg / L, 25℃ organic (tetracycline) solution as the target pollutant, 100mg of geopolymer and 5mg of PMS were added to the solution. The mixture was stirred in the dark for 30 minutes to reach adsorption-desorption equilibrium. A xenon lamp was turned on and the solution was irradiated at a distance of about 15cm from the mouth of the beaker for 30 minutes. Samples were taken every 5 minutes and detected using a UV spectrophotometer.

[0105] Comparative Example 5

[0106] The porous geopolymer in this comparative example includes iron tailings, steel slag, red mud, alkali activator, water-reducing agent, foaming agent, and foam stabilizer. The mass fraction of iron tailings in the solid powder is 70% (70g), and the mass fractions of steel slag and red mud are 25% (25g) and 5% (5g), respectively. The water glass modulus of the alkali activator is 3.3, and the amount added is 40wt% (40g) of the solid powder. The amount added of calcium carbide slag is 10wt% (10g) of the solid powder. The amount added of water-reducing agent is 0.55wt% (0.55g) of the solid powder. The amount added of hydrogen peroxide solution in the foaming agent is 0wt% (0g) of the solid powder, and the amount added of 1,3-disulfonylhydrazidebenzene is 1.1wt% (1.1g) of the solid powder. The amount added of foam stabilizer is 0.8wt% (0.8g) of the solid powder.

[0107] After mixing iron tailings, steel slag and red mud evenly according to the above proportions, water glass and calcium carbide slag are added in proportion. After mechanically stirring evenly, polycarboxylate superplasticizer, foaming agent and SDS are added. Then the mixture is poured into a mold and cured at room temperature of 25℃ for 24 hours, then cured at 150℃ in an oven for 8 hours, and then cured at room temperature for 7 days.

[0108] Using a 100ml, 50mg / L, 25℃ organic (tetracycline) solution as the target pollutant, 100mg of geopolymer and 5mg of PMS were added to the solution. The mixture was stirred in the dark for 30 minutes to reach adsorption-desorption equilibrium. A xenon lamp was turned on and the solution was irradiated at a distance of about 15cm from the mouth of the beaker for 30 minutes. Samples were taken every 5 minutes and detected using a UV spectrophotometer.

[0109] Comparative Example 6

[0110] The porous geopolymer in this comparative example includes iron tailings, steel slag, red mud, alkali activator, water-reducing agent, foaming agent, and foam stabilizer. The mass fraction of iron tailings in the solid powder is 70% (70g), and the mass fractions of steel slag and red mud are 25% (25g) and 5% (5g), respectively. The water glass modulus of the alkali activator is 3.3, and the amount added is 40wt% (40g) of the solid powder. The amount added of calcium carbide slag is 10wt% (10g) of the solid powder. The amount added of water-reducing agent is 0.55wt% (0.55g) of the solid powder. The amount added of hydrogen peroxide solution in the foaming agent is 1.1% (1.1g) of the solid powder, and the amount added of 1,3-disulfonylhydrazidebenzene is 0wt% (0g) of the solid powder. The amount added of foam stabilizer is 0.8wt% (0.8g) of the solid powder.

[0111] After mixing iron tailings, steel slag and red mud evenly according to the above proportions, water glass and calcium carbide slag are added in proportion. After mechanically stirring evenly, polycarboxylate superplasticizer, foaming agent and SDS are added. Then the mixture is poured into a mold and cured at room temperature of 25℃ for 24 hours, then cured at 150℃ in an oven for 8 hours, and then cured at room temperature for 7 days.

[0112] Using a 100ml, 50mg / L, 25℃ organic (tetracycline) solution as the target pollutant, 100mg of geopolymer and 5mg of PMS were added to the solution. The mixture was stirred in the dark for 30 minutes to reach adsorption-desorption equilibrium. A xenon lamp was turned on and the solution was irradiated at a distance of about 15cm from the mouth of the beaker for 30 minutes. Samples were taken every 5 minutes and detected using a UV spectrophotometer.

[0113] The degradation effects of organic compounds (tetracycline) in Comparative Examples 1-6 were tested, and the results are shown in Table 2.

[0114] Table 2. Degradation effect of comparative organic compounds (tetracycline)

[0115]

[0116] Table 1 shows that the geopolymer has a very significant degradation effect on organic matter (tetracycline), especially in Example 10, where the removal rate of organic matter (tetracycline) reached 95.86%. This is attributed to the excellent pore structure of the geopolymer and the abundant iron element brought by steel slag and red mud, which can provide sufficient catalytic sites for the reaction. Under light irradiation, it generates a large number of active free radicals, such as SO42-. ·− O2 -·OH and other reactive free radicals can participate in oxidation reactions, stripping electrons from TC molecules. Sulfate radicals and hydroxyl radicals are both highly oxidizing agents. In these reactions, TC molecules lose electrons, forming oxidation products. This process may lead to molecular breakage or the formation of products with higher oxidation states. The free radicals react with carbon-carbon or carbon-hydrogen bonds in the TC molecule, leading to chain breakage or the formation of new chemical bonds. Therefore, according to the composition of this invention, geopolymers with excellent porous structures can be obtained, such as… Figure 2 The image shown is an electron microscope image of the porous geopolymer prepared in Example 10; the active sites of iron are fully exposed, resulting in an extremely outstanding effect in degrading organic matter.

[0117] As can be seen from Table 2, the degradation effect of organic matter (tetracycline) is significantly reduced when any one or more components of the present invention are missing. The main reason is that without any component of the present invention, it is impossible to obtain a geopolymer with excellent porous structure, and its ability to expose active sites is not outstanding, resulting in a significant decrease in degradation effect.

[0118] In summary, this invention discloses a method for preparing a porous geopolymer and its application in the degradation of organic matter. The porous geopolymer material is composed of iron tailings, steel slag, red mud, alkali activator, foaming agent, foam stabilizer, and water-reducing agent. By modifying and utilizing industrial waste iron tailings, steel slag, and red mud, a geopolymer with a porous structure is successfully prepared. The prepared geopolymer possesses abundant pores, providing more photocatalytic active sites. It can improve the removal efficiency of organic matter in water while reducing the cost of organic matter treatment and realizing the secondary utilization of waste resources. It effectively solves the problems of tailings accumulation and environmental pollution, providing favorable conditions for the high-value-added utilization of industrial solid waste and has good application prospects.

[0119] The various embodiments of the present invention have now been described. The above description is exemplary and not exhaustive, nor is it limited to the described embodiments. Many modifications and variations will be included within the scope and spirit of the described embodiments by those skilled in the art without departing from the scope and spirit of the invention.

Claims

1. The application of a porous geopolymer in the degradation of organic matter, characterized in that the application method comprises: mixing the porous geopolymer with organic wastewater, adding potassium persulfate (PMS), and stirring in the dark to achieve adsorption. Desorption equilibrium was achieved, and stirring was performed simultaneously under xenon lamp illumination; the organic compound was tetracycline. The porous geopolymer comprises the following raw materials: Solid powder: iron tailings, steel slag, and red mud; wherein, the mass fraction of iron tailings in the solid powder is 70%; and the mass fraction of steel slag is 5%. 25%; the mass fraction of red mud is 25%. 5%; the sum of the mass fractions of the three is 100%; Alkali activator: water glass and carbide slag, wherein the mass ratio of water glass to carbide slag is 1:

1. 4:4 1; The mass ratio of water glass to solid powder is 1:

1. 4:10; the mass ratio of the carbide slag to the solid powder is 1. 4:10; Foaming agent: hydrogen peroxide solution and 1,3 disulfonylhydrazidebenzene, wherein hydrogen peroxide solution and 1,3 The mass ratio of disulfonylhydrazide to benzene is 0.

1. 1.0:0.1 1.0; The mass ratio of the hydrogen peroxide solution to the solid powder is 0.

1. 1.0:100; the 1,3 The mass ratio of disulfonylhydrazidebenzene to solid powder is 0.

1. 1.0:100; Foam stabilizer: The mass ratio of the foam stabilizer to the solid powder is 0.

8. 1.0:100; Water-reducing agent: The mass ratio of the water-reducing agent to the solid powder is 0.

55. 0.80:100; The foam stabilizer is sodium dodecyl sulfate (SDS). The water-reducing agent is a polycarboxylate high-efficiency water-reducing agent; The iron tailings have a particle size of less than 0.070 mm and need to be heated to 300℃ before use. Calcination at 700℃ for 1 minute 3 h; the steel slag particle size is less than 0.070 mm, and the red mud particle size is less than 0.085 mm. It needs to be heated to 60℃ before use. Dry at 100℃ to constant weight.

2. The application of a porous geopolymer as described in claim 1 in the degradation of organic matter, characterized in that, The mass percentage of each component in the iron tailings is: SiO2 30%. 50%, Al2O3 10% 20%, Fe2O3 20% 30%, CaO 5% 10%, MgO 1% 3%, K2O 1% 3%, Na2O 1% 3%, TiO2 1% 2%, MnO 0.1% 0.5%, with a loss on ignition of 0.4%. 1%.

3. The application of a porous geopolymer as described in claim 1 in the degradation of organic matter, characterized in that, The water glass has a modulus of 3.3 and a solid content of 34 wt%; the hydrogen peroxide solution has a concentration of 10 wt%. 30wt%.

4. The application of a porous geopolymer as described in claim 1 in the degradation of organic matter, characterized in that, The preparation method of the porous geopolymer includes the following steps: Step S1: Mix iron tailings, steel slag and red mud evenly in proportion to obtain solid mixture A; Step S2: Water glass and calcium carbide slag are mixed in proportion, stirred and mixed evenly, and then left to stand for a period of time to obtain an alkaline activator; Step S3: Hydrogen peroxide solution and 1,3 Disulfonylhydrazide benzene is mixed in a certain proportion, stirred and mixed evenly, and then left to stand for a period of time to obtain a foaming agent; Step S4: Add the solid mixture A obtained in step S1 to the alkali activator obtained in step S2; after mixing, mechanically stir to obtain a slurry B; Step S5: Add the foaming agent obtained in step S3 to the mixed slurry B obtained in step S4, and then mechanically stir to obtain mixed slurry C. Step S6: Pour the mixed slurry C into the mold and continuously vibrate to remove air from the slurry; Step S7: Seal the sample together with the mold, cure it at room temperature and in an oven, and cure it at room temperature after demolding.

5. The application of a porous geopolymer as described in claim 4 in the degradation of organic matter, characterized in that, The room temperature for curing is 24°C. 28℃, curing time is 12 48 hours, oven curing temperature is 80 150℃, curing time is 8 hours 12 hours, followed by 7 hours of room temperature curing. 14 days.

6. The application of a porous geopolymer as described in claim 1 in the degradation of organic matter, characterized in that, The light-protected stirring time is 30 minutes. 60 minutes.

7. The application of a porous geopolymer as described in claim 1 in the degradation of organic matter, characterized in that, The concentration of organic matter in the organic wastewater is 10. 100 mg / L, pH value 2 7. The peak value of the ultraviolet spectrum is 265. 275nm.

8. The application of a porous geopolymer as described in claim 1 in the degradation of organic matter, characterized in that, The amount of potassium persulfate PMS added is 50. 300 mg / L, xenon lamp light source intensity is 70 80 cd, illumination time is 30 60 minutes, stirring speed 800 1000 r / min.

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