Preparation method and application of efficient composite deep fluorine removal agent

Abstract

The invention discloses a preparation method and application of an efficient composite deep fluorine removal agent, and relates to the technical field of environmental engineering, S1, material selection, S2, material pretreatment, S3, mixed reaction, S4, hydrothermal synthesis, S5, drying and forming, and S6, chemical modification and heat treatment. According to the invention, high-efficiency adsorption materials such as nano aluminum oxide and nano iron oxide are introduced and matched with a biomass material to form a composite adsorption system, so that the adsorption capacity is improved, and the renewability and environmental protection property of the material are enhanced; due to introduction of rare earth elements, the rare earth elements are added as active components, and the selective adsorption capacity of the fluorine removal agent to fluorine ions is enhanced by utilizing the unique electronic structure and chemical activity of the rare earth elements; by adopting a hydrothermal synthesis technology, energy consumption and environmental pollution are reduced, and meanwhile, non-toxic or low-toxicity raw materials are used, so that the safety and sustainability of the preparation process are ensured.

Description

Technical Field

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

[0002] Fluorine is an element that exists widely in nature, but excessive intake can cause serious harm to human health. Long-term drinking of high-fluoride water can lead to diseases such as dental fluorosis and skeletal fluorosis, and even affect the nervous and immune systems. At present, many regions around the world (such as China, India, and some African countries) are facing the problem of excessive fluoride in drinking water, especially in areas with abundant groundwater resources. Fluoride pollution has become a public health problem that needs to be solved urgently. With the advancement of science and technology, the research and development of new fluoride removal materials (such as nanomaterials, biomaterials) and intelligent water treatment systems has brought new hope to the field of fluoride removal. In the future, fluoride removal technology will pay more attention to green 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 defluorinating agent, which records "using desulfurized gypsum as raw material, first calcining at 500-600°C for 2-3h, and then heating at a specific rate for secondary calcination, and the calcined product is screened and compounded with a silicate cement modified product and moss ash to obtain a finished product. The defluorinating 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 defluorination effect of complex water bodies. Not only that, the environmental protection issue of the defluorinating 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 shortcomings, 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: A method for preparing a high-efficiency composite deep defluorination agent comprises the following steps: S1. Select materials, use nano-alumina (Al2O3) and nano-iron oxide (Fe3O4) as the main adsorption components, the ratio of nano-alumina to nano-iron oxide is 3:2, use 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, add rare earth elements as active components, use their unique electronic structure and chemical activity to improve the selective adsorption capacity of fluoride ions; S2, material pretreatment, including dispersion of nanomaterials, dissolution of biomass materials and activation of rare earth elements; S3, mixing reaction, adding the dispersed nano-alumina and nano-iron oxide suspensions into the reaction container in proportion, stirring at a low speed (200-300rpm) for 10 minutes to ensure initial uniform mixing, slowly adding the biomass material solution during stirring to avoid gelation caused by excessive local concentration, slowly adding the lanthanum ion solution dropwise into the mixed solution, while maintaining the stirring speed at 300-400rpm 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 ensure that the components are fully combined and form a stable composite structure, and 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 defluorination agent; S6. Chemical modification and heat treatment: soak the dried defluorinating 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.

[0007] Preferably, the biomass material is chitosan or a cellulose derivative, and the rare earth element is lanthanum or cerium.

[0008] 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.

[0009] Preferably, in the biomass material dissolving step, the biomass material is dissolved in a 1% acetic acid solution and stirred until completely dissolved to form a transparent colloid.

[0010] 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.

[0011] Preferably, in step S3, the reaction temperature is controlled at 25-30° C. to avoid high temperature causing degradation of chitosan or agglomeration of nanomaterials.

[0012] Preferably, in the step S4, the composite slurry is slowly transferred to a high-pressure reactor, the filling amount does not exceed 70% of the volume of the reactor, 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.

[0013] An application of the high-efficiency composite deep defluorinating agent as described above is characterized by: application of the preparation method of the high-efficiency composite deep defluorinating agent in the field of environmental engineering technology.

[0014] The beneficial effects of the present invention are as follows: in the preparation method and application of the high-efficiency composite deep defluorination agent: The combination of nanomaterials and biomaterials, on the basis of 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 protection of the materials; 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 defluoridation agents for fluoride ions; Adopt hydrothermal synthesis technology to reduce energy consumption and environmental pollution. At the same time, use non-toxic or low-toxic raw materials to ensure the safety and sustainability of the preparation process. Chemical modification and heat treatment: the dried defluorinating agent 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

[0015] The present invention will now be described by way of example with reference to the accompanying drawings, in which: 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

[0016] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0017] like Figure 1 As shown, a method for preparing a high-efficiency composite deep defluorination agent comprises the following steps: S1. Select materials, use nano-alumina (Al2O3) and nano-iron oxide (Fe3O4) as the main adsorption components, the ratio of nano-alumina to nano-iron oxide is 3:2, use 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, add rare earth elements as active components, use their unique electronic structure and chemical activity to improve the selective adsorption capacity of fluoride ions; On the basis of traditional defluoridation agents, high-efficiency adsorption materials such as nano-alumina and nano-iron oxide are introduced, and biomass materials (such as chitosan and cellulose derivatives) are combined to form a composite adsorption system. This combination not only improves the adsorption capacity, but also enhances the renewability and environmental protection of the materials. S2, material pretreatment, including dispersion of nanomaterials, dissolution of biomass materials and activation of rare earth elements; S3, mixing reaction, adding the dispersed nano-alumina and nano-iron oxide suspensions into the reaction container in proportion, stirring at a low speed (200-300rpm) for 10 minutes to ensure initial uniform mixing, slowly adding the biomass material solution during stirring to avoid gelation caused by excessive local concentration, slowly adding the lanthanum ion solution dropwise into the mixed solution, while maintaining the stirring speed at 300-400rpm 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 ensure that the components are fully combined and form a stable composite structure, and 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 defluorination agent; S6. Chemical modification and heat treatment: soak the dried defluorinating 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.

[0018] Specifically, the biomass material is chitosan or a cellulose derivative, and the rare earth element is lanthanum or cerium.

[0019] 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.

[0020] Specifically, in the biomass material dissolving step, the biomass material is dissolved in an acetic acid solution with a concentration of 1%, and stirred until it is completely dissolved to form a transparent colloid.

[0021] Specifically, 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.

[0022] Specifically, in step S3, the reaction temperature is controlled at 25-30° C. to avoid high temperature causing degradation of chitosan or agglomeration of nanomaterials.

[0023] 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.

[0024] An application of the high-efficiency composite deep defluorinating agent as described above is characterized by: application of the preparation method of the high-efficiency composite deep defluorinating agent in the field of environmental engineering technology.

[0025] Implementation case 1: Household drinking water treatment 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.

[0026] Using the high-efficiency composite deep defluorination agent in the preparation plan (compounding nano-alumina, nano-iron oxide, chitosan, and lanthanum ions), a small household defluorination filter is designed, integrating a fluoride ion sensor and an intelligent monitoring system.

[0027] Optimization point application: Material innovation: The introduction of nanomaterials and lanthanum ions improves the adsorption capacity and selectivity.

[0028] Preparation process: The hydrothermal synthesis process ensures the stability and uniformity of the composite material.

[0029] Performance optimization: Surface modification technology enhances the anti-interference ability and service life of the defluorination agent.

[0030] Implementation effect:

[0031] After treatment, the fluoride ion concentration of drinking water dropped from 5 mg / L to below 0.5 mg / L, meeting the national drinking water standards.

[0032] The intelligent monitoring system displays water quality data in real time and reminds users to replace filters with easy operation.

[0033] Comparative analysis: Traditional method: using activated alumina filter element, which has low adsorption capacity and needs frequent replacement.

[0034] The advantages of this patented high-efficiency composite deep defluorination agent are: high adsorption efficiency, long service life and good user experience.

[0035] Implementation Case 2: Industrial Wastewater Treatment 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.

[0036] The high-efficiency composite deep defluorination agent in the preparation scheme of this patent is used in the dynamic adsorption column system in the industrial wastewater treatment process, combined with membrane separation technology and automatic control devices.

[0037] Material innovation: The introduction of the rare earth element lanthanum improves the selective adsorption capacity of fluoride ions.

[0038] Preparation process: Green synthesis process reduces energy consumption and pollution in the production process.

[0039] Performance optimization: Dynamic adsorption and regeneration technology realizes the recycling of defluorination agents and reduces operating costs.

[0040] Implementation effect:

[0041] After treatment, the fluoride ion concentration in the wastewater drops to below 10 mg / L, meeting the emission standards.

[0042] Comparative analysis: Traditional method: using lime sedimentation method, which produces a large amount of sludge and has low treatment efficiency.

[0043] Advantages of this patented solution: no secondary pollution, high adsorption efficiency and low operating cost.

[0044] Implementation case 3: soil remediation Due to 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.

[0045] The highly efficient composite deep defluoridating agent in the preparation scheme of this patent is used, the defluoridating agent is mixed with the soil, and combined with plant restoration technology (such as planting fluorine-resistant plants).

[0046] Material innovation: The introduction of biomass material chitosan enhances the environmental friendliness and renewability of the defluorination agent.

[0047] Preparation process: Microencapsulation technology achieves the sustained release effect of the defluoridation agent and prolongs the repair cycle.

[0048] Performance optimization: Anti-interference performance optimization ensures the stability of the defluoridator in complex soil environments.

[0049] Implementation effect:

[0050] After remediation, the fluoride ion concentration in the soil dropped from 500 mg / kg to below 100 mg / kg, meeting the safety standard.

[0051] Phytoremediation technology further fixes fluoride ions in the soil and restores the ecological functions of the soil.

[0052] Comparative analysis: Traditional method: using lime or phosphate for repair, which has short-term effect and easily causes soil compaction.

[0053] The advantages of this patented solution: long-lasting restoration effect, good environmental protection, combined with plant restoration technology, high comprehensive benefits.

[0054] To sum up: The summary and comparison are as follows:

[0055] 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.

[0056] The above is based on the present invention as an inspiration. Through the above description, relevant staff can make various changes and modifications without departing from the technical idea of ​​this invention. The technical scope of this invention is not limited to the content in the specification, and its technical scope 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, use nano-alumina (Al2O3) and nano-iron oxide (Fe3O4) as the main adsorption components, the ratio of nano-alumina to nano-iron oxide is 3:2, introduce biomass materials as biomass carriers, and add rare earth elements as active components; S2, material pretreatment, including dispersion of nanomaterials, dissolution of biomass materials and activation of rare earth elements; S3, mixing reaction, adding the dispersed nano-alumina and nano-iron oxide suspensions into the reaction container in proportion, stirring at a low speed (200-300rpm) for 10 minutes to ensure initial uniform mixing, slowly adding the biomass material solution during stirring to avoid gelation caused by excessive local concentration, slowly adding the lanthanum ion solution dropwise into the mixed solution, while maintaining the stirring speed at 300-400rpm 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 allow the components to fully combine 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 defluorination agent; S6. Chemical modification and heat treatment: the dried defluorinating agent is immersed in a 1% silane coupling agent solution for 2 hours, and heat treated 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, characterized in that: 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, characterized in that: 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.

4. The method for preparing a high-efficiency composite deep defluorination agent according to claim 1, characterized in that: 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.

5. The method for preparing a high-efficiency composite deep defluorination agent according to claim 1, characterized in that: 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.

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

7. The method for preparing a high-efficiency composite deep defluorination agent according to claim 1, characterized in that: In the step S4, the composite slurry is slowly transferred to a high-pressure reactor, with the filling amount not exceeding 70% of the volume of the reactor. 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.

8. An application of the high-efficiency composite deep defluorination agent according to any one of claims 1 to 7, 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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