Preparation method and application of a high-efficiency composite deep defluorination agent

Abstract

The present invention discloses a preparation method and application of a high-efficiency composite deep defluoridating agent, which relates to the field of environmental engineering technology, including S1, material selection, S2, material pretreatment, S3, mixing reaction, S4, hydrothermal synthesis, S5, drying and molding, and S6, chemical modification and heat treatment. In the invention, nanomaterials and biomaterials are combined. On the basis of traditional defluoridating agents, high-efficiency adsorption materials such as nanoalumina and nanoiron oxide are introduced, and biomass materials are matched to form a composite adsorption system. This combination not only improves the adsorption capacity, but also enhances the renewability and environmental protection of the material. Rare earth elements are introduced as active components, and their unique electronic structure and chemical activity are utilized to enhance the selective adsorption capacity of the defluoridating agent for fluoride ions. Hydrothermal synthesis technology is used to reduce energy consumption and environmental pollution. At the same time, non-toxic or low-toxic raw materials are used to ensure the safety and sustainability of the preparation process.

Description

Technical Field

[0001] The present invention relates to the field of environmental engineering technology, and in particular to a preparation method and application of a high-efficiency composite deep defluorination agent. Background Art

[0002] Fluorine is a widely present element in nature, but excessive intake can pose serious risks to human health. Long-term consumption of high-fluoride water can lead to conditions such as dental fluorosis and skeletal fluorosis, and can even affect the nervous and immune systems. Currently, many regions around the world (such as China, India, and parts of Africa) are facing the problem of excessive fluoride in drinking water. Especially in areas with abundant groundwater resources, fluoride pollution has become an urgent public health issue. With advances in science and technology, the development of new fluoride removal materials (such as nanomaterials and biomaterials) and intelligent water treatment systems has brought new hope to the field of fluoride removal. In the future, fluoride removal technology will place greater emphasis on environmental protection and resource recycling, providing more reliable protection for global drinking water safety.

[0003] According to the announcement number, CN117258763B - A method for preparing a high-efficiency composite deep defluoridating agent, it is recorded that "desulfurized gypsum is used as raw material, first calcined at 500-600°C for 2-3 hours, and then the temperature is increased at a specific rate for secondary calcination. The calcined product is screened and compounded with a modified product of silicate cement and moss ash to obtain a finished product. The defluoridating agent of the present invention has good surface properties and adsorption activity, can effectively remove fluoride ions in the mixed system, and has the advantages of high removal rate and fast speed." Although it has a certain removal rate, it still cannot meet the defluoridation effect of complex water bodies. Not only that, the environmental protection issue of the defluoridating agent is also a link that needs attention.

[0004] In summary, a preparation method and application of a high-efficiency composite deep defluorination agent were designed. Summary of the Invention

[0005] In order to overcome the above-mentioned deficiencies, the present invention provides a preparation method and application of a high-efficiency composite deep defluorination agent.

[0006] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0007] A method for preparing a high-efficiency composite deep defluorination agent comprises the following steps:

[0008] S1. Select materials, using nano-alumina (Al2O3) and nano-iron oxide (Fe3O4) as the main adsorption components, with a ratio of 3:2. Utilize their high specific surface area and strong adsorption capacity, introduce biomass materials as biomass carriers to enhance the mechanical strength and renewability of the materials, and add rare earth elements as active components to utilize their unique electronic structure and chemical activity to improve the selective adsorption capacity of fluoride ions;

[0009] S2, material pretreatment, including dispersion of nanomaterials, dissolution of biomass materials and activation of rare earth elements;

[0010] S3, mixing reaction, adding the dispersed nano-alumina and nano-iron oxide suspensions in proportion to the reaction vessel, stirring at a low speed (200-300 rpm) for 10 minutes to ensure preliminary uniform mixing, slowly adding the biomass material solution during the stirring process to avoid gelation caused by excessive local concentration, and slowly adding the lanthanum ion solution dropwise to the mixed solution while maintaining the stirring speed at 300-400 rpm to ensure uniform distribution of the lanthanum ions;

[0011] S4, hydrothermal synthesis, transfer the composite slurry to a high-pressure reactor, and perform hydrothermal reaction at 120° C. for 6 hours to ensure that the components are fully combined and form a stable composite structure. After the reaction is completed, naturally cool to room temperature, slowly release the pressure, and open the reactor;

[0012] S5, drying and molding, filtering and washing the slurry after the reaction, drying it at 80°C, and finally molding it by mechanical pressing to obtain a granular defluoridating agent;

[0013] S6. Chemical modification and heat treatment: soak the dried defluorination agent in a 1% silane coupling agent solution for 2 hours to enhance the hydrophobicity and stability of the material, and heat treat it at 300°C for 2 hours to further improve the crystallinity and adsorption performance of the material.

[0014] Preferably, the biomass material is chitosan or a cellulose derivative, and the rare earth element is lanthanum or cerium.

[0015] Preferably, in the nanomaterial dispersion step, nano-aluminum oxide and nano-iron oxide are dispersed in deionized water respectively, and ultrasonic treatment is performed for 20 to 40 minutes to ensure uniform dispersion of the particles.

[0016] Preferably, in the biomass material dissolving step, the biomass material is dissolved in a 1% acetic acid solution and stirred until it is completely dissolved to form a transparent colloid.

[0017] Preferably, in the activation step of the rare earth element, the rare earth element (such as lanthanum salt or lanthanum nitrate) is dissolved in deionized water, and the pH is adjusted to 5-6 to form a stable lanthanum ion solution.

[0018] Preferably, in step S3, the reaction temperature is controlled at 25-30° C. to avoid degradation of chitosan or agglomeration of nanomaterials due to high temperature.

[0019] Preferably, in the S4 step, the composite slurry is slowly transferred to a high-pressure reactor, with the filling amount not exceeding 70% of the reactor volume, and sufficient space is reserved to prevent excessive pressure. After the reactor is sealed, it is placed in a heating device and heated to 120°C at a heating rate of 5°C / min.

[0020] An application of the high-efficiency composite deep defluoridation agent as described above is characterized by: application of the preparation method of the high-efficiency composite deep defluoridation agent in the field of environmental engineering technology.

[0021] The beneficial effects of the present invention are as follows: in the preparation method and application of the high-efficiency composite deep defluorination agent:

[0022] The combination of nanomaterials and biomaterials, based on traditional defluoridation agents, introduces high-efficiency adsorption materials such as nano-alumina and nano-iron oxide, and combines them with biomass materials to form a composite adsorption system. This combination not only improves the adsorption capacity, but also enhances the renewability and environmental friendliness of the materials.

[0023] The introduction of rare earth elements, adding rare earth elements as active components, using their unique electronic structure and chemical activity to enhance the selective adsorption capacity of fluoride removal agents for fluoride ions;

[0024] Adopting hydrothermal synthesis technology to reduce energy consumption and environmental pollution, while using non-toxic or low-toxic raw materials to ensure the safety and sustainability of the preparation process;

[0025] Chemical modification and heat treatment: the dried defluoridant was immersed in a 1% silane coupling agent solution for 2 hours to enhance the hydrophobicity and stability of the material, and then heat treated at 300 ° C for 2 hours to further improve the crystallinity and adsorption performance of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will now be described by way of example with reference to the accompanying drawings, in which:

[0027] Figure 1 It is a step diagram of the preparation method of the high-efficiency composite deep defluorination agent of the present invention. DETAILED DESCRIPTION

[0028] The present invention will now be described in further detail with reference to the accompanying drawings, which are simplified schematic diagrams that illustrate the basic structure of the present invention in a schematic manner.

[0029] like Figure 1 As shown, a method for preparing a high-efficiency composite deep defluorination agent comprises the following steps:

[0030] S1. Select materials, using nano-alumina (Al2O3) and nano-iron oxide (Fe3O4) as the main adsorption components, with a ratio of 3:2. Utilize their high specific surface area and strong adsorption capacity, introduce biomass materials as biomass carriers to enhance the mechanical strength and renewability of the materials, and add rare earth elements as active components to utilize their unique electronic structure and chemical activity to improve the selective adsorption capacity of fluoride ions;

[0031] On the basis of traditional defluoridation agents, high-efficiency adsorption materials such as nano-alumina and nano-iron oxide are introduced and combined with biomass materials (such as chitosan and cellulose derivatives) to form a composite adsorption system. This combination not only improves the adsorption capacity, but also enhances the reproducibility and environmental friendliness of the materials.

[0032] S2, material pretreatment, including dispersion of nanomaterials, dissolution of biomass materials and activation of rare earth elements;

[0033] S3, mixing reaction, adding the dispersed nano-alumina and nano-iron oxide suspensions in proportion to the reaction vessel, stirring at a low speed (200-300 rpm) for 10 minutes to ensure preliminary uniform mixing, slowly adding the biomass material solution during the stirring process to avoid gelation caused by excessive local concentration, and slowly adding the lanthanum ion solution dropwise to the mixed solution while maintaining the stirring speed at 300-400 rpm to ensure uniform distribution of the lanthanum ions;

[0034] S4, hydrothermal synthesis, transfer the composite slurry to a high-pressure reactor, and perform hydrothermal reaction at 120° C. for 6 hours to ensure that the components are fully combined and form a stable composite structure. After the reaction is completed, naturally cool to room temperature, slowly release the pressure, and open the reactor;

[0035] S5, drying and molding, filtering and washing the slurry after the reaction, drying it at 80°C, and finally molding it by mechanical pressing to obtain a granular defluoridating agent;

[0036] S6. Chemical modification and heat treatment: soak the dried defluorination agent in a 1% silane coupling agent solution for 2 hours to enhance the hydrophobicity and stability of the material, and heat treat it at 300°C for 2 hours to further improve the crystallinity and adsorption performance of the material.

[0037] Specifically, the biomass material is chitosan or a cellulose derivative, and the rare earth element is lanthanum or cerium.

[0038] Specifically, in the nanomaterial dispersion step, nano-aluminum oxide and nano-iron oxide are dispersed in deionized water respectively, and ultrasonic treatment is used for 20 to 40 minutes to ensure that the particles are evenly dispersed.

[0039] Specifically, in the biomass material dissolving step, the biomass material is dissolved in a 1% acetic acid solution and stirred until it is completely dissolved to form a transparent colloid.

[0040] Specifically, in the rare earth element activation step, the rare earth element (such as lanthanum salt or lanthanum nitrate) is dissolved in deionized water, and the pH is adjusted to 5-6 to form a stable lanthanum ion solution.

[0041] Specifically, in step S3, the reaction temperature is controlled at 25-30° C. to avoid degradation of chitosan or aggregation of nanomaterials caused by high temperature.

[0042] Specifically, in the S4 step, the composite slurry is slowly transferred to a high-pressure reactor, the filling amount does not exceed 70% of the reactor volume, and sufficient space is reserved to prevent excessive pressure. After the reactor is sealed, it is placed in a heating device and heated to 120°C at a heating rate of 5°C / min.

[0043] An application of the high-efficiency composite deep defluoridation agent as described above is characterized by: application of the preparation method of the high-efficiency composite deep defluoridation agent in the field of environmental engineering technology.

[0044] Implementation Case 1: Household Drinking Water Treatment

[0045] The fluoride ion concentration in household drinking water in a high-fluoride area exceeds the standard, and deep defluoridation treatment is required to ensure the safety of drinking water.

[0046] Using the high-efficiency composite deep defluoridation agent in the preparation plan (compounding nano-alumina, nano-iron oxide, chitosan, and lanthanum ions), a small household defluoridation filter element is designed, integrating a fluoride ion sensor and an intelligent monitoring system.

[0047] Optimization point application:

[0048] Material innovation: The introduction of nanomaterials and lanthanum ions improves adsorption capacity and selectivity.

[0049] Preparation process: The hydrothermal synthesis process ensures the stability and uniformity of the composite material.

[0050] Performance optimization: Surface modification technology enhances the anti-interference ability and service life of the defluorination agent.

[0051] Implementation effect:

[0052] After treatment, the fluoride ion concentration in drinking water dropped from 5 mg / L to below 0.5 mg / L, meeting the national drinking water standards.

[0053] The intelligent monitoring system displays water quality data in real time and reminds users to replace the filter element with easy operation.

[0054] Comparative analysis:

[0055] Traditional method: using activated alumina filter element, which has low adsorption capacity and needs frequent replacement.

[0056] The advantages of this patented high-efficiency composite deep defluorination agent are: high adsorption efficiency, long service life and good user experience.

[0057] Implementation Case 2: Industrial Wastewater Treatment

[0058] The fluoride ion concentration in the wastewater discharged by a fluorine chemical enterprise is as high as 200 mg / L, and deep treatment is required to meet environmental protection requirements.

[0059] The high-efficiency composite deep defluoridating agent prepared in this patent is used in a dynamic adsorption column system in the industrial wastewater treatment process, combined with membrane separation technology and automated control devices.

[0060] Material innovation: The introduction of the rare earth element lanthanum improves the selective adsorption capacity of fluoride ions.

[0061] Preparation process: Green synthesis process reduces energy consumption and pollution in the production process.

[0062] Performance optimization: Dynamic adsorption and regeneration technology realizes the recycling of defluorination agents and reduces operating costs.

[0063] Implementation effect:

[0064] After treatment, the fluoride ion concentration in the wastewater drops to below 10 mg / L, meeting the emission standards.

[0065] Comparative analysis:

[0066] Traditional method: lime precipitation method is used, which produces a large amount of sludge and has low treatment efficiency.

[0067] Advantages of this patented solution: no secondary pollution, high adsorption efficiency and low operating cost.

[0068] Implementation Case 3: Soil Remediation

[0069] Due to the long-term use of fluorine-containing pesticides, the fluoride ion concentration in a certain farmland soil exceeds the standard and needs to be repaired to restore soil health.

[0070] The high-efficiency composite deep defluoridant in this patented preparation scheme is used, the defluoridant is mixed with the soil, and combined with plant remediation technology (such as planting fluorine-resistant plants).

[0071] Material innovation: The introduction of biomass material chitosan enhances the environmental friendliness and renewability of the defluoridation agent.

[0072] Preparation process: Microencapsulation technology achieves the sustained release effect of the defluoridating agent and prolongs the repair cycle.

[0073] Performance optimization: Anti-interference performance optimization ensures the stability of the defluoridator in complex soil environments.

[0074] Implementation effect:

[0075] After remediation, the fluoride ion concentration in the soil dropped from 500 mg / kg to below 100 mg / kg, meeting safety standards.

[0076] Phytoremediation technology further fixes fluoride ions in the soil and restores the ecological functions of the soil.

[0077] Comparative analysis:

[0078] Traditional methods: using lime or phosphate for repair, which has short-term effects and can easily cause soil compaction.

[0079] Advantages of this patented solution: long-lasting restoration effect, good environmental protection, combined with plant restoration technology, and high comprehensive benefits.

[0080] To sum up: the summary and comparison are as follows:

[0081]

[0082] Through the above three implementation cases, the high-efficiency composite deep defluorination agent has demonstrated significant advantages in different application scenarios, verifying the practical application value of its preparation method and optimization points.

[0083] The above description is for inspiration. Based on the above description, relevant personnel can make various changes and modifications without departing from the technical concept of this invention. The technical scope of this invention is not limited to the content of the specification, but must be determined according to the scope of the claims.

Claims

1. A method for preparing a high-efficiency composite deep defluorination agent, characterized in that: The following steps are involved: S1. Select materials, using nano-alumina (Al2O3) and nano-iron oxide (Fe3O4) as the main adsorption components, with a ratio of nano-alumina to nano-iron oxide of 3:2, introducing biomass materials as biomass carriers, and adding rare earth elements as active components; S2. Material pretreatment, including dispersion of nanomaterials, dissolution of biomass materials, and activation of rare earth elements. Specific steps include dispersing nano-alumina and nano-iron oxide in deionized water, treating with ultrasound for 20 to 40 minutes, dissolving the biomass materials in a 1% acetic acid solution, and stirring until completely dissolved to form a transparent colloid; dissolving the rare earth elements in deionized water and adjusting the pH to 5 to 6 to form a stable lanthanum ion solution; S3, mixing reaction, adding the dispersed nano-alumina and nano-iron oxide suspensions in proportion to the reaction vessel, stirring at a low speed of 200-300 rpm for 10 minutes to ensure preliminary uniform mixing, slowly adding the biomass material solution during stirring to avoid gelation caused by excessive local concentration, and slowly adding the lanthanum ion solution dropwise to the mixed solution while maintaining the stirring speed at 300-400 rpm to ensure uniform distribution of lanthanum ions; S4, hydrothermal synthesis, transfer the composite slurry to a high-pressure reactor and perform hydrothermal reaction at 120°C for 6 hours to fully combine the components and form a stable composite structure. After the reaction is completed, naturally cool to room temperature, slowly release the pressure and open the reactor; S5, drying and molding, filtering and washing the slurry after the reaction, drying it at 80°C, and finally molding it by mechanical pressing to obtain a granular defluoridating agent; S6. Chemical modification and heat treatment: soak the dried defluorination agent in a 1% silane coupling agent solution for 2 hours, and heat treat it at 300°C for 2 hours to further improve the crystallinity and adsorption performance of the material.

2. The method for preparing a high-efficiency composite deep defluorination agent according to claim 1, wherein: The biomass material is chitosan or a cellulose derivative, and the rare earth element is lanthanum or cerium.

3. The method for preparing a high-efficiency composite deep defluorination agent according to claim 1, wherein: In the step S3, the reaction temperature is controlled at 25-30°C.

4. The method for preparing a high-efficiency composite deep defluorination agent according to claim 1, wherein: In the step S4, the composite slurry is slowly transferred to a high-pressure reactor with a filling amount not exceeding 70% of the reactor volume. After the reactor is sealed, it is placed in a heating device and heated to 120° C. at a heating rate of 5° C. / min.

5. An application of the high-efficiency composite deep defluorination agent according to any one of claims 1 to 4, characterized in that: The application of the preparation method of the high-efficiency composite deep defluorination agent in the field of environmental engineering technology.

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