A filter core for simulating the water quality of the groundwater in Emei Mountain, a preparation method and a filter

Abstract

The application discloses a filter core for simulating the quality of Emei Mountain underground water, a preparation method and a filter. The filter core comprises modified volcanic breccia, modified basalt, modified dolomite, modified limestone, activated carbon and a polymer. Through the synergistic effect of the modified volcanic breccia, the modified basalt, the modified dolomite, the modified limestone and the activated carbon, impurities in drinking water can be adsorbed and removed, and various minerals can be separated through ion exchange, so that the content of various minerals in water is increased. In combination with water-rock interaction, drinking water with the quality of Emei Mountain underground water can be simulated by using the filter core.

Description

A filter element for simulating groundwater quality in Mount Emei, its preparation method, and the filter itself. Technical Field

[0001] This application relates to the field of water treatment technology, and in particular to a filter element and preparation method for simulating the groundwater quality of Mount Emei and a filter. Background Technology

[0002] Drinking water is the most basic, active, and widespread factor for maintaining human life because, compared to food, the beneficial and harmful chemicals in drinking water are more easily absorbed by the human body. On the one hand, drinking water provides the human body with essential macro- and micro-elements, maintaining the body's mineral balance; on the other hand, almost all known biogeochemical diseases and endemic diseases are related to drinking water quality. my country has a vast territory with many high-quality mineral water springs, among which the development of Emei Mountain mineral water has a history of nearly 40 years. Emei Mountain possesses extremely rich water resources. Testing has shown that "Emei Mountain Mineral Water" is a low-temperature mineral water composed of calcium bicarbonate, strontium, and bromine, and contains various mineral elements beneficial to the human body, such as calcium, magnesium, phosphorus, and iron.

[0003] Currently, the main way people obtain high-quality mineral water from Emei Mountain is by purchasing bottled water produced in Emei Mountain. However, due to the high cost of bottled water, it is difficult for most families to use it as their daily drinking water. Therefore, how to treat tap water to achieve the water quality of Emei Mountain mineral water through water treatment equipment has become a major issue in water treatment. Summary of the Invention

[0004] In view of this, this application provides a filter element and preparation method for simulating the groundwater quality of Mount Emei, and a filter for preparing drinking water that simulates the groundwater quality of Mount Emei.

[0005] The embodiments of this application are implemented as follows: a filter element simulating the groundwater quality of Mount Emei is provided, comprising: modified volcanic breccia, modified basalt, modified dolomite, modified limestone, activated carbon, and polymer.

[0006] Optionally, in some embodiments of this application, the filter element comprises, by weight, 5-10 parts of modified volcanic breccia, 10-25 parts of modified basalt, 10-25 parts of modified dolomite, 10-20 parts of modified limestone, 25-40 parts of activated carbon, and 25-50 parts of polymer.

[0007] Optionally, in some embodiments of this application, the modified volcanic breccia is volcanic breccia that has been acid-modified and then calcined; and / or

[0008] The modified volcanic breccia has a grain size range of 35–100 mesh; and / or

[0009] The modified basalt is basalt that has undergone oxidation modification followed by alkali modification; and / or

[0010] The modified basalt has a grain size range of 60–200 mesh; and / or

[0011] The modified dolomite is dolomite that has undergone molten salt modification, thermal activation, and carbonation; and / or

[0012] The modified limestone is limestone that has been calcined, reacted with nano-silica, treated with steam, and carbonated; and / or

[0013] The polymer is selected from at least one of polypropylene, polyethylene, polyvinyl alcohol, and polytetrafluoroethylene; and / or

[0014] The activated carbon is selected from coconut shell activated carbon.

[0015] Accordingly, this application also provides a method for preparing a filter element simulating the groundwater quality of Mount Emei, comprising: providing volcanic breccia, basalt, dolomite, and limestone, and modifying the volcanic breccia, basalt, dolomite, and limestone respectively to obtain modified volcanic breccia, modified basalt, modified dolomite, and modified limestone; providing activated carbon and a polymer, mixing the activated carbon and the polymer with the modified volcanic breccia, modified basalt, modified dolomite, and modified limestone to obtain a mixture; and firing the mixture to obtain the filter element.

[0016] Optionally, in some embodiments of this application, the volcanic breccia is the Permian volcanic breccia of Mount Emei; and / or the grain size range of the volcanic breccia is 1-5 mm; and / or the basalt is the Permian Emeishan basalt of Mount Emei, and the basalt is amygdaloidal basalt; and / or the grain size range of the basalt is 1-5 mm; and / or the dolomite is the Silurian dolomite of Mount Emei; and / or the grain size range of the dolomite is 35-100 mesh; and / or the limestone is the Maokou Formation limestone of the Permian of Mount Emei; and / or the grain size range of the limestone is 35-200 mesh; and / or the polymer is selected from at least one of polypropylene, polyethylene, polyvinyl alcohol and polytetrafluoroethylene; and / or the activated carbon is selected from coconut shell activated carbon.

[0017] Optionally, in some embodiments of this application, the method for modifying the volcanic breccia is as follows: the volcanic breccia is soaked in an acidic solution, and the resulting solid is calcined at 200–300°C for 30–60 min to obtain the modified volcanic breccia; and / or the particle size range of the modified volcanic breccia is 35–100 mesh; and / or the method for modifying the basalt is as follows: the basalt is mixed in an oxidizing solution, and then the resulting solid is mixed in an alkaline solution to obtain the modified basalt; and / or the particle size range of the modified basalt is 60–200 mesh; and / or the method for modifying the dolomite is as follows: the dolomite is impregnated in a molten salt solution and stirred at 75–85°C for 15–20 min. The mixture is dried at 110–120°C for 1.5–2 hours, and then activated in an inert atmosphere at 450–550°C for 2–3 hours. After cooling, it is heated in a CO2 atmosphere to 350–400°C at a heating rate of 6–8°C / min and held at this temperature for 30–90 minutes for carbonation modification to obtain the modified dolomite; and / or the method for modifying the limestone is as follows: the limestone is calcined at 800–900°C for 2–3 hours, cooled, and mixed with nano-silica. The mixed powder is reacted at 600–700°C for 1.5–2 hours, cooled, and reacted in a steam atmosphere for 2–3 hours. Then, it is carbonated in a CO2 atmosphere at 400–500°C for 1–2 hours to obtain the modified limestone.

[0018] Optionally, in some embodiments of this application, the acidic solution is selected from at least one of sulfuric acid aqueous solution, hydrochloric acid aqueous solution, and nitric acid aqueous solution; and / or the oxidizing solution is selected from hydrogen peroxide solution; and / or the alkaline solution is selected from at least one of sodium hydroxide solution, potassium hydroxide solution, and ammonia water; and / or the molten salt solution comprises molten salt and water, wherein the mass ratio of the molten salt to the dolomite is 0.1 to 0.3:1; and / or the molten salt solution comprises molten salt and water, wherein the molten salt is selected from one or more of NaNO3 or KNO3 and LiNO3; and / or the mass ratio of the limestone to the nano-silica is 1:1 to 3.

[0019] Optionally, in some embodiments of this application, the acidic solution is selected from a sulfuric acid aqueous solution with a volume fraction of 10%–15%, or a hydrochloric acid aqueous solution with a concentration of 0.5–1 mol / L, or a nitric acid aqueous solution with a concentration of 0.5–1 mol / L; and / or the soaking time of the volcanic breccia in the acidic solution is 2–3 hours; and / or the mass percentage concentration of the oxidizing solution is 5–8%; and / or the concentration of the alkaline solution is 0.5–1.5 mol / L; and / or the basalt is mixed in the oxidizing solution... The mixing time is 55-65℃ for 20-30 hours; and / or the mixing method of placing the basalt in the oxidizing solution is one or more of shaking, stirring, or rotary mixing; and / or in the method of modifying the basalt, the temperature of placing the obtained solid in the alkaline solution is 70-80℃ for 2-3 hours; and / or in the method of modifying the basalt, the mixing method of placing the obtained solid in the alkaline solution is stirring first, followed by ultrasonication.

[0020] Optionally, in some embodiments of this application, the step of mixing the activated carbon and the polymer, as well as the modified volcanic breccia, the modified basalt, the modified dolomite, and the modified limestone to obtain a mixture includes: mixing 25-40 parts by mass of the activated carbon and 25-50 parts by mass of the polymer, as well as 5-10 parts by mass of the modified volcanic breccia, 10-25 parts by mass of the modified basalt, 10-25 parts by mass of the modified dolomite, and 10-20 parts by mass of the modified limestone to obtain the mixture.

[0021] Accordingly, this application also provides a filter, including the filter element simulating the groundwater quality of Mount Emei as described above, or a filter element prepared by the preparation method of the filter element simulating the groundwater quality of Mount Emei as described above.

[0022] Optionally, in some embodiments of this application, the filter further includes: a housing and two end caps, the filter element having a hollow cylindrical structure, the end caps respectively covering both ends of the filter element, and the filter element placed inside the housing.

[0023] The filter element of this application includes modified volcanic breccia, modified basalt, modified dolomite, modified limestone, activated carbon, and polymer. Through the synergistic effect of modified volcanic breccia, modified basalt, modified dolomite, modified limestone, and activated carbon, impurities in drinking water can be adsorbed and removed. Furthermore, various minerals can be precipitated through ion exchange, thereby increasing the content of various minerals in the water. Combined with the water-rock interaction, the filter element can simulate the drinking water quality of groundwater from Mount Emei. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 is a schematic flowchart of an embodiment of a method for preparing a filter element that simulates the groundwater quality of Mount Emei provided in this application;

[0026] Figure 2 is another schematic flowchart of an embodiment of a method for preparing a filter element that simulates the groundwater quality of Mount Emei provided in this application;

[0027] Figure 3 is a structural schematic diagram of an embodiment of a filter provided in this application;

[0028] Figure 4 is a SEM image of the unmodified basalt from Example 1;

[0029] Figure 5 is a SEM image of the modified basalt of Example 1;

[0030] Figure 6 is a SEM image of the unmodified dolomite from Example 1;

[0031] Figure 7 is a SEM image of the modified dolomite of Example 1;

[0032] Figure 8 is a SEM image of the unmodified limestone from Example 1;

[0033] Figure 9 is a SEM image of the modified limestone of Example 1. Detailed Implementation

[0034] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application. In this application, unless otherwise stated, directional terms such as "upper" and "lower" specifically refer to the drawing directions in the accompanying drawings. In addition, in the description of this application, the term "including" means "including but not limited to". Various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and conciseness and should not be construed as a hard limitation on the scope of the present invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single values ​​within that range. For example, it should be assumed that the description of a range from 1 to 6 specifically discloses subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the range referred to.

[0035] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0036] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one," "at least one of the following," or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c," or "at least one of a, b, and c," can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0037] Current water treatment equipment and technologies primarily remove contaminants from water. For example, the widely used reverse osmosis technology removes minerals along with contaminants. However, there are currently no effective technologies for simulating the quality of mineral water. Some studies have attempted to remineralize drinking water using rocks such as maifanite to increase its mineral content. However, the interaction between natural rocks and water requires a long time, making it difficult to release beneficial minerals in a short soaking period. Furthermore, because Emei Mountain mineral water undergoes layers of filtration through rare ancient rocks, it possesses a unique mineral composition and proportion. Therefore, simulating the formation of Emei Mountain mineral water presents significant technical challenges, and currently, no relevant technologies or products exist. Emei Mountain mineral water contains various minerals; testing has shown it to be a low-temperature mineral water containing calcium bicarbonate, strontium, and bromine, as well as calcium, magnesium, phosphorus, iron, and other minerals beneficial to the human body. Analysis of the hydrogeochemical characteristics and water quality evolution mechanism of Emeishan mineral water reveals that it is mainly controlled by the water-rock interaction of volcanic breccia, basalt, dolomite, and limestone. Based on this, this application provides a filter element simulating the groundwater quality of Emeishan, comprising: modified volcanic breccia, modified basalt, modified dolomite, modified limestone, activated carbon, and polymer.

[0038] The filter element provided in this application comprises modified volcanic breccia, modified basalt, modified dolomite, modified limestone, activated carbon, and polymers. Through the synergistic effect of these materials, it can adsorb and remove impurities from drinking water. Furthermore, ion exchange can precipitate various minerals, thereby increasing the content of various minerals in the water. Combined with the water-rock interaction, this filter element can simulate the drinking water quality of groundwater from Mount Emei. Moreover, this method of simulating groundwater quality from Mount Emei reduces costs compared to bottled water from the Mount Emei region, thus enabling its widespread application.

[0039] Among these, the modified volcanic breccia has a large pore volume and specific surface area, thus providing a larger contact area with water when using the filter cartridge to treat water, thereby improving the ion exchange performance of the volcanic breccia. The modified basalt has a rougher surface and more pores, and this structural change is conducive to water-rock interaction. The modified dolomite has a large average pore size and specific surface area, which supports the stable precipitation of minerals when using the filter cartridge to treat water. The modified limestone has a highly stable pore structure, which is beneficial to the stable precipitation of minerals from the modified limestone. Water-rock interaction (WRI) refers to the interaction between fluids and rocks that occurs during geological processes.

[0040] In one embodiment, the filter element comprises, by weight, 5-10 parts of modified volcanic breccia, 10-25 parts of modified basalt, 10-25 parts of modified dolomite, 10-20 parts of modified limestone, 25-40 parts of activated carbon, and 25-50 parts of polymer.

[0041] In this embodiment, the filter element includes all components within the specified content range. When the filter element is used to filter water, drinking water with a quality simulating that of groundwater from Mount Emei can be obtained. Furthermore, the modified volcanic breccia, modified basalt, modified dolomite, and modified limestone can firmly adhere to the polymer, preventing the high turbidity and color of the water caused by the dissolution and dispersion of these materials. It also avoids filter element clogging due to a high polymer content.

[0042] In one embodiment, the modified volcanic breccia is an acid-modified volcanic breccia that has been calcined. Specifically, the method for modifying the volcanic breccia is as follows: the volcanic breccia with a particle size range of 1-5 mm is immersed in an acidic solution, and the resulting solid is calcined at 200-300°C for 30-60 minutes to obtain the modified volcanic breccia.

[0043] In this embodiment, the modified volcanic breccia obtained through modification treatment has increased pore volume and specific surface area. Thus, when the filter element is used to treat water, the contact area between the modified volcanic breccia and water can be increased, thereby improving the ion exchange performance of the volcanic breccia.

[0044] The acidic solution can be selected from inorganic acid solutions, such as at least one of sulfuric acid aqueous solution, hydrochloric acid aqueous solution, and nitric acid aqueous solution. Specifically, the acidic solution can be a sulfuric acid aqueous solution with a volume fraction of 10% to 15%, a hydrochloric acid aqueous solution with a concentration of 0.5 to 1 mol / L, or a nitric acid aqueous solution with a concentration of 0.5 to 1 mol / L. After acid treatment, some of the material blocking the pores in the volcanic breccia is dissolved by the inorganic acid, improving the pore structure and increasing the contact area between the volcanic breccia and water.

[0045] In one specific embodiment, the acidic solution may be selected from an aqueous solution of sulfuric acid with a volume fraction of 10% to 15%.

[0046] In one embodiment, the soaking time of the volcanic breccia in an acidic solution can be 2-3 hours, specifically 2.0-2.2 hours, 2.2-2.5 hours, 2.5-2.8 hours, 2.8-3.0 hours, etc. This time range allows the acidic solution to fully modify the volcanic breccia.

[0047] In one embodiment, the modified volcanic breccia has a grain size range of 35–100 mesh, specifically 35–50 mesh, 50–80 mesh, 80–100 mesh, etc. This grain size range allows the modified volcanic breccia to have a larger specific surface area, increasing the contact area with water and improving ion exchange performance, thus better simulating the drinking water quality of groundwater in Mount Emei.

[0048] Specifically, volcanic breccia particles with a diameter range of 1–5 mm can be obtained by crushing the volcanic breccia. That is, by crushing natural volcanic breccia, smaller particles with a diameter range of 1–5 mm can be obtained. Furthermore, the volcanic breccia can be washed before crushing to remove impurities.

[0049] In one embodiment, the volcanic breccia is a natural volcanic breccia. Specifically, the volcanic breccia is the Permian volcanic breccia from Mount Emei, and its main minerals are quartz, feldspar, pyroxene, and amphibole.

[0050] In one specific embodiment, after soaking in an acidic solution, the solid is filtered, repeatedly rinsed with distilled water, thoroughly dried, and then calcined in a muffle furnace at 200–300°C. After cooling, it is pulverized with a pulverizer and screened into powder of 35–100 mesh to obtain modified volcanic breccia.

[0051] In one embodiment, the modified basalt is basalt that has undergone oxidation modification followed by alkali modification. In this embodiment, oxidation modification can improve the surface hydrophilicity of the basalt, while alkali modification makes the surface of the modified basalt rougher and increases the number of pores after alkali etching. This structural change is conducive to water-rock interaction.

[0052] Furthermore, the method for modifying the basalt can be as follows: the basalt with a particle size range of 1 to 5 mm is placed in an oxidizing solution for mixing treatment, and then the resulting solid is placed in an alkaline solution for mixing treatment to obtain modified basalt.

[0053] The oxidizing solution can be selected from hydrogen peroxide solution. Specifically, the mass percentage concentration of the oxidizing solution is 5-8%, such as 5-6%, 6-7%, 7-8%, etc. It is understood that the solvent in the oxidizing solution can be water. The oxidizing solution can oxidize and modify the basalt while avoiding excessive acidity that would hinder subsequent modification treatment.

[0054] In one embodiment, the basalt is placed in an oxidizing solution and treated at a temperature of 55–65°C for 20–30 hours. This temperature promotes and accelerates the oxidation modification, which is beneficial for the process.

[0055] Specifically, the mixing process is one or more of the following methods: shaking, stirring, or rotating to promote the mixing of the oxidizing solution with the basalt and to promote the oxidation of the basalt by the oxidizing solution.

[0056] The alkaline solution is selected from at least one of sodium hydroxide solution, potassium hydroxide solution, and ammonia water. Specifically, the concentration of the alkaline solution is 0.5–1.5 mol / L, such as 0.5–0.8 mol / L, 0.8–1.0 mol / L, 1.0–1.2 mol / L, 1.5–1.5 mol / L, etc. The alkaline solution within this concentration range can react with the basalt without wasting the alkaline solution.

[0057] In one embodiment, after the basalt is mixed in an oxidizing solution, the resulting solid is then mixed in an alkaline solution at a temperature of 70–80°C for 2–3 hours. This temperature promotes and accelerates the alkaline modification, which is beneficial for the process. Specifically, the alkaline solution can be heated in a water bath to reach the specified temperature.

[0058] Furthermore, the basalt can be mixed in an alkaline solution by stirring and / or ultrasound. Specifically, stirring can be performed alone, ultrasound can be performed alone, or ultrasound can be performed simultaneously with stirring.

[0059] In one specific embodiment, the basalt is placed in an alkaline solution for mixing treatment by first stirring and then ultrasonication. In this embodiment, stirring is performed first to promote the mixing and contact between the alkaline solution and the basalt, and then ultrasonication is performed to allow the alkaline solution to further penetrate into the pores of the basalt, thereby promoting the alkaline etching of the basalt by the alkaline solution.

[0060] Specifically, when the basalt is placed in an alkaline solution for stirring and / or ultrasonication, the entire solution system can be a closed system, such as being placed in a sealed container or having the container sealed, to prevent the evaporation and reduction of solvents and water in the alkaline solution during heating and stirring, which would affect the alkaline modification effect.

[0061] Specifically, basalt can be crushed to obtain basalt particles with a diameter range of 1–5 mm. That is, by crushing natural basalt, smaller particles with a diameter range of 1–5 mm can be obtained. Furthermore, the basalt can be washed before crushing to remove impurities.

[0062] In one embodiment, the basalt is natural basalt. Specifically, the basalt is the Emeishan Permian basalt, which is amygdaloidal basalt, and its main minerals include plagioclase, albite, potassium feldspar, and pyroxene.

[0063] In one specific embodiment, the modified basalt is prepared as follows: After cleaning the basalt, it is crushed into basalt particles of 1-5 mm. It is first soaked in a 5% hydrogen peroxide solution and shaken at 60°C for 24 hours. After that, it is taken out, washed, and dried. Then it is soaked in a 1 mol / L sodium hydroxide solution. During the soaking process, it is sealed with plastic wrap and heated in a 75°C water bath. It is first stirred for 2 hours and then sonicated for 1 hour. Then the solid is taken out, washed, dried, and cooled. It is then crushed with a pulverizer and screened into 60-200 mesh rocks to obtain the modified basalt.

[0064] In one embodiment, the modified dolomite is dolomite that has undergone molten salt modification, thermal activation, and carbonation. In this embodiment, the modified dolomite obtained through modification has a large average pore size and specific surface area, which can support mineral stability when the filter cartridge is used to treat water.

[0065] Specifically, the molten salt can be one or more of NaNO3, KNO3, and LiNO3.

[0066] Specifically, the method for modifying the dolomite is as follows: the dolomite is immersed in a molten salt solution, stirred at 75-85°C for 15-20 min, and dried at 110-120°C for 1.5-2 h. The resulting solid is then thermally activated at 450-550°C for 2-3 h in an inert atmosphere. After cooling, it is placed in a CO2 atmosphere and heated to 350-400°C at a heating rate of 6-8°C / min. The temperature is then maintained at this temperature for 30-90 min to carry out carbonation modification, thereby obtaining the modified dolomite.

[0067] The molten salt solution comprises molten salt (solute) and water (solvent). The mass ratio of the molten salt to the dolomite is 0.1–0.3:1, such as 0.1–0.1.5:1, 0.15–0.2:1, 0.2–0.25:1, 0.25–0.3:1, etc. Specifically, the mass of the molten salt can be determined based on the mass of the dolomite, then the molten salt can be completely dissolved in water to prepare a molten salt solution, and the dolomite can be immersed in the molten salt solution.

[0068] In one embodiment, during the thermal activation, the inert atmosphere may be, but is not limited to, at least one of nitrogen, argon, and helium.

[0069] In this embodiment, dolomite is immersed in a molten salt solution, allowing the molten salt to enter the dolomite. During thermal activation, the molten salt, such as NaNO3, melts. The molten salt promotes ion diffusion through ionic liquid channels, effectively activating the dolomite and causing MgCO3 in the dolomite to decompose into MgO as much as possible, while CaCO3 does not decompose. During carbonation, CaCO3 can promote MgO to absorb CO2, carbonizing MgO into MgCO3. That is, by modifying the dolomite, the original crystal structure of CaMg(CO3)2 in the natural dolomite is destroyed. The newly generated CaMg(CO3)2 after modification can be more easily and slowly decomposed under the action of water flow during water treatment, which is conducive to the stable precipitation of calcium and magnesium minerals in the modified dolomite.

[0070] In one embodiment, the dolomite is natural dolomite. Specifically, the dolomite is Silurian dolomite from Mount Emei, with dolomite as the main mineral, and minor amounts of feldspar and calcite.

[0071] In one embodiment, the dolomite has a particle size range of 35 to 100 mesh, which can be obtained by crushing natural dolomite.

[0072] In one specific embodiment, the modified dolomite preparation method is as follows: after cleaning the dolomite, it is crushed into powder of 35-100 mesh. The dolomite powder is impregnated in NaNO3 solution with a mass ratio of dolomite to NaNO3 of 0.1-0.3:1. The mixture is stirred at 80°C for 15 min, then dried at 120°C for 2 h, activated at 500°C for 2 h in a nitrogen atmosphere, cooled, and then carbonated in a 100% CO2 atmosphere. The temperature is then increased from room temperature to 400°C at a rate of 6°C / min, maintained at 400°C for 60 min, and cooled to room temperature in a CO2 atmosphere to obtain the modified dolomite.

[0073] In one embodiment, the modified limestone is limestone that has been calcined, mixed and reacted with nano-silica, then treated with steam and carbonated.

[0074] In this embodiment, the stability of the pore structure of the modified limestone is improved by modification, which is beneficial to the stable precipitation of minerals in the modified limestone.

[0075] Specifically, the method for modifying the limestone is as follows: calcining the limestone at 800-900℃ for 2-3 hours, cooling it, mixing it with nano-silica, reacting the mixed powder at 600-700℃ for 1.5-2 hours, cooling it, reacting it in a steam atmosphere for 2-3 hours, and then carbonating it in a CO2 atmosphere at 400-500℃ for 1-2 hours to obtain the modified limestone.

[0076] The mass ratio of the limestone to the nano-silica can be 1:1 to 3, that is, the mass of the limestone to the mass of the nano-silica = 1:1 to 3, specifically 1:1 to 1.5, 1:1.5 to 2, 1:2 to 2.5, 1:2.5 to 3, etc.

[0077] In this embodiment, the limestone is calcined to obtain CaO. Nano-SiO2 and CaO undergo a mixed reaction at high temperature. The two interact with each other, thereby increasing the diffusion rate of CO2 into the small pores of the limestone during subsequent carbonation treatment, which improves the stability of the modified limestone pore structure. After the limestone is treated with water vapor, the water vapor reacts with CaO to generate Ca(OH)2. After carbonation in a CO2 atmosphere, CaCO3 is formed, which is beneficial to the stable precipitation of minerals in the modified limestone.

[0078] In one embodiment, the limestone is a natural limestone. Specifically, the limestone is the Maokou Formation limestone of the Permian system in Emeishan, and its main minerals are calcite, with minor amounts of quartz and clay minerals.

[0079] In one embodiment, the limestone has a particle size range of 35 to 200 mesh, which can be obtained by crushing natural limestone.

[0080] In one specific embodiment, the modified limestone preparation method is as follows: after cleaning the limestone, it is crushed into powder of 35-200 mesh. The limestone powder is calcined at 800-900℃ for 3 hours. After cooling, it is mixed with nano-silica (SiO2) in a ratio of limestone:SiO2 of 1:1-3. The mixed powder is placed in a muffle furnace and reacted at 600-700℃ for 2 hours. After cooling, it is reacted in a steam atmosphere for 2 hours, and then transferred to a 100% CO2 atmosphere at 450℃ for 1 hour for carbonation. Finally, it is cooled to room temperature in a CO2 atmosphere to obtain the modified limestone.

[0081] In one embodiment, the polymer may be selected from, but is not limited to, at least one of polypropylene, polyethylene, polyvinyl alcohol, and polytetrafluoroethylene. In a specific embodiment, the polymer is selected from polyethylene.

[0082] In one embodiment, the activated carbon can be selected from coconut shell activated carbon. Coconut shell activated carbon is activated carbon produced from coconut shell raw materials, and has characteristics such as high strength, regeneration after saturation, high adsorption capacity, and low resistance. The activated carbon has good adsorption properties and can work synergistically with modified volcanic breccia, modified basalt, modified dolomite, modified limestone, etc., to adsorb and remove impurities in drinking water. Furthermore, it can precipitate various minerals through ion exchange, thereby simulating the drinking water quality of Emei Mountain groundwater by using the filter element.

[0083] Specifically, the particle size range of the activated carbon can be 80-200 mesh, such as 80-100 mesh, 100-120 mesh, 120-150 mesh, 150-180 mesh, 180-200 mesh, etc.

[0084] This application provides a method for preparing a filter element simulating the groundwater quality of Mount Emei. Referring to Figures 1 and 2, Figure 1 is a schematic flowchart of an embodiment of the method for preparing a filter element simulating the groundwater quality of Mount Emei provided in this application, and Figure 2 is a schematic flowchart of another embodiment of the method for preparing a filter element simulating the groundwater quality of Mount Emei provided in this application. The preparation method includes the following steps:

[0085] Step S11: Provide volcanic breccia, basalt, dolomite and limestone, and modify the volcanic breccia, basalt, dolomite and limestone respectively to obtain modified volcanic breccia, modified basalt, modified dolomite and modified limestone;

[0086] Step S12: Provide activated carbon and polymer, and mix the activated carbon and polymer with the modified volcanic breccia, the modified basalt, the modified dolomite and the modified limestone to obtain a mixture;

[0087] Step S13: The mixture is fired to obtain the filter element.

[0088] In this embodiment, volcanic breccia, basalt, dolomite, and limestone are modified respectively. The modified volcanic breccia, modified basalt, modified dolomite, and modified limestone are then mixed with activated carbon and polymers and pressed to form a filter element that simulates the groundwater quality of Mount Emei. When drinking water is treated through this filter element, the synergistic effect of the modified volcanic breccia, modified basalt, modified dolomite, modified limestone, and activated carbon can adsorb and remove impurities in the drinking water. Furthermore, various minerals can be precipitated through ion exchange, thereby increasing the content of various minerals in the water. Combined with the water-rock interaction, drinking water with the quality of groundwater from Mount Emei can be simulated by using this filter element.

[0089] In step S11:

[0090] The volcanic breccia, basalt, dolomite, and limestone mentioned can be referenced from the relevant content of volcanic breccia, basalt, dolomite, and limestone in the filter element provided in this application, and will not be elaborated here.

[0091] In one embodiment, the modification treatment of the volcanic breccia specifically includes: soaking the volcanic breccia with a particle size range of 1 to 5 mm in an acidic solution, and calcining the resulting solid at 200 to 300°C for 30 to 60 minutes to obtain the modified volcanic breccia.

[0092] In this embodiment, the volcanic breccia is modified to obtain modified volcanic breccia, which has increased pore volume and specific surface area. Thus, when the filter element is used to treat water, the contact area between the modified volcanic breccia and water can be increased, thereby improving the ion exchange performance of the volcanic breccia.

[0093] The acidic solution can be selected from inorganic acid solutions, such as at least one of sulfuric acid aqueous solution, hydrochloric acid aqueous solution, and nitric acid aqueous solution. Specifically, the acidic solution can be a sulfuric acid aqueous solution with a volume fraction of 10% to 15%, a hydrochloric acid aqueous solution with a concentration of 0.5 to 1 mol / L, or a nitric acid aqueous solution with a concentration of 0.5 to 1 mol / L. After acid treatment, some of the material blocking the pores in the volcanic breccia is dissolved by the inorganic acid, improving the pore structure and increasing the contact area between the volcanic breccia and water.

[0094] In one specific embodiment, the acidic solution may be selected from an aqueous solution of sulfuric acid with a volume fraction of 10% to 15%.

[0095] In one embodiment, the soaking time of the volcanic breccia in an acidic solution can be 2-3 hours, specifically 2.0-2.2 hours, 2.2-2.5 hours, 2.5-2.8 hours, 2.8-3.0 hours, etc. This time range allows the acidic solution to fully modify the volcanic breccia.

[0096] In one embodiment, the modified volcanic breccia has a grain size range of 35–100 mesh, specifically 35–50 mesh, 50–80 mesh, 80–100 mesh, etc. This grain size range allows the modified volcanic breccia to have a larger specific surface area, increasing the contact area with water and improving ion exchange performance, thus better simulating the drinking water quality of groundwater in Mount Emei.

[0097] Specifically, volcanic breccia particles with a diameter range of 1–5 mm can be obtained by crushing the volcanic breccia. That is, by crushing natural volcanic breccia, smaller particles with a diameter range of 1–5 mm can be obtained. Furthermore, the volcanic breccia can be washed before crushing to remove impurities.

[0098] In one embodiment, the volcanic breccia is a natural volcanic breccia. Specifically, the volcanic breccia is the Permian volcanic breccia from Mount Emei, and its main minerals are quartz, feldspar, pyroxene, and amphibole.

[0099] In one specific embodiment, after soaking in an acidic solution, the solid is filtered, repeatedly rinsed with distilled water, thoroughly dried, and then calcined in a muffle furnace at 200–300°C. After cooling, it is pulverized with a pulverizer and screened into powder of 35–100 mesh to obtain modified volcanic breccia.

[0100] In one embodiment, the modification treatment of the basalt specifically includes: first oxidizing the basalt, and then alkali modifying it. Specifically, the basalt with a particle size range of 1-5 mm is mixed in an oxidizing solution, and then the resulting solid is mixed in an alkaline solution to obtain modified basalt.

[0101] In this embodiment, the basalt is modified by oxidation and alkali, which can improve the surface hydrophilicity of the basalt. The modified basalt is then etched with alkali to increase the surface roughness, increase the number of pores, and the structural changes are conducive to the rock-water interaction.

[0102] The oxidizing solution can be selected from hydrogen peroxide solution. Specifically, the mass percentage concentration of the oxidizing solution is 5-8%, such as 5-6%, 6-7%, 7-8%, etc. It is understood that the solvent in the oxidizing solution can be water. The oxidizing solution can oxidize and modify the basalt while avoiding excessive acidity that would hinder subsequent modification treatment.

[0103] In one embodiment, the basalt is placed in an oxidizing solution and treated at a temperature of 55–65°C for 20–30 hours. This temperature promotes and accelerates the oxidation modification, which is beneficial for the process.

[0104] Specifically, the mixing process involves shaking, stirring, or rotating to promote the mixing of the oxidizing solution with the basalt and to promote the oxidation of the basalt by the oxidizing solution.

[0105] The alkaline solution is selected from at least one of sodium hydroxide solution, potassium hydroxide solution, and ammonia water. Specifically, the concentration of the alkaline solution is 0.5–1.5 mol / L, such as 0.5–0.8 mol / L, 0.8–1.0 mol / L, 1.0–1.2 mol / L, 1.5–1.5 mol / L, etc. The alkaline solution within this concentration range can react with the basalt without wasting the alkaline solution.

[0106] In one embodiment, after the basalt is mixed in an oxidizing solution, the resulting solid is then mixed in an alkaline solution at a temperature of 70–80°C for 2–3 hours. This temperature promotes and accelerates the alkaline modification, which is beneficial for the process. Specifically, the alkaline solution can be heated in a water bath to reach the specified temperature.

[0107] Furthermore, the basalt can be mixed in an alkaline solution by stirring and / or ultrasound. Specifically, stirring can be performed alone, ultrasound can be performed alone, or ultrasound can be performed simultaneously with stirring.

[0108] In one specific embodiment, the basalt is placed in an alkaline solution for mixing treatment by first stirring and then ultrasonication. In this embodiment, stirring is performed first to promote the mixing and contact between the alkaline solution and the basalt, and then ultrasonication is performed to allow the alkaline solution to further penetrate into the pores of the basalt, thereby promoting the alkaline etching of the basalt by the alkaline solution.

[0109] Specifically, when the basalt is placed in an alkaline solution for stirring and / or ultrasonication, the entire solution system can be a closed system, such as being placed in a sealed container or having the container sealed, to prevent the evaporation and reduction of solvents and water in the alkaline solution during heating and stirring, which would affect the alkaline modification effect.

[0110] Specifically, basalt can be crushed to obtain basalt particles with a diameter range of 1–5 mm. That is, by crushing natural basalt, smaller particles with a diameter range of 1–5 mm can be obtained. Furthermore, the basalt can be washed before crushing to remove impurities.

[0111] In one embodiment, the basalt is natural basalt. Specifically, the basalt is the Emeishan Permian basalt, which is amygdaloidal basalt, and its main minerals include plagioclase, albite, potassium feldspar, and pyroxene.

[0112] In one specific embodiment, the modified basalt is prepared as follows: After cleaning the basalt, it is crushed into basalt particles of 1-5 mm. It is first soaked in a 5% hydrogen peroxide solution and shaken at 60°C for 24 hours. After that, it is taken out, washed, and dried. Then it is soaked in a 1 mol / L sodium hydroxide solution. During the soaking process, it is sealed with plastic wrap and heated in a 75°C water bath. It is first stirred for 2 hours and then sonicated for 1 hour. Then the solid is taken out, washed, dried, and cooled. It is then crushed with a pulverizer and screened into 60-200 mesh rocks to obtain the modified basalt.

[0113] In one embodiment, the modification treatment of the dolomite specifically includes: molten salt modification, thermal activation, and carbonation of the dolomite. Specifically, the dolomite is immersed in a molten salt solution, stirred at 75–85°C for 15–20 min, and dried at 110–120°C for 1.5–2 h. The resulting solid is then activated in an inert atmosphere at 450–550°C for 2–3 h. After cooling, it is placed in a CO2 atmosphere and heated to 350–400°C at a heating rate of 6–8°C / min, and held at this temperature for 30–90 min to perform carbonation modification, thereby obtaining the modified dolomite.

[0114] In this embodiment, the modified dolomite obtained by modifying the dolomite has a larger average pore size and specific surface area, which can support the stability of minerals when the filter element is used to treat water.

[0115] Furthermore, in this embodiment, dolomite is immersed in a molten salt solution, allowing the molten salt to enter the dolomite. During thermal activation, the molten salt, such as NaNO3, melts. The molten salt promotes ion diffusion through ionic liquid channels, effectively activating the dolomite and causing MgCO3 in the dolomite to decompose into MgO as much as possible, while CaCO3 does not decompose. During carbonation, CaCO3 can promote MgO to absorb CO2, carbonizing MgO into MgCO3. That is, by modifying the dolomite, the original crystal structure of CaMgCO3 in the natural dolomite is destroyed. The newly generated CaMgCO3 after modification is more easily and slowly decomposed under the action of water flow during water treatment, which is conducive to the stable precipitation of calcium and magnesium minerals in the modified dolomite.

[0116] The molten salt solution comprises molten salt (solute) and water (solvent). The mass ratio of the molten salt to the dolomite is 0.1–0.3:1, such as 0.1–0.1.5:1, 0.15–0.2:1, 0.2–0.25:1, 0.25–0.3:1, etc. Specifically, the mass of the molten salt can be determined based on the mass of the dolomite, then the molten salt can be completely dissolved in water to prepare a molten salt solution, and the dolomite can be immersed in the molten salt solution. The molten salt can be one or more of NaNO3, KNO3, or LiNO3.

[0117] The inert atmosphere can be, but is not limited to, at least one of nitrogen, argon and helium.

[0118] In one embodiment, the dolomite is natural dolomite. Specifically, the dolomite is Silurian dolomite from Mount Emei, with dolomite as the main mineral, and minor amounts of feldspar and calcite.

[0119] In one embodiment, the dolomite has a particle size range of 35 to 100 mesh, specifically obtained by crushing natural dolomite. The method for crushing the dolomite is a method known in the art for crushing rocks.

[0120] In one specific embodiment, the modified dolomite preparation method is as follows: after cleaning the dolomite, it is crushed into powder of 35-100 mesh. The dolomite powder is impregnated in NaNO3 solution with a mass ratio of dolomite to NaNO3 of 0.1-0.3:1. The mixture is stirred at 80°C for 15 min, then dried at 120°C for 2 h, activated at 500°C for 2 h in a nitrogen atmosphere, cooled, and then carbonated in a 100% CO2 atmosphere. The temperature is then increased from room temperature to 400°C at a rate of 6°C / min, maintained at 400°C for 60 min, and cooled to room temperature in a CO2 atmosphere to obtain the modified dolomite.

[0121] In one embodiment, the modification treatment of the limestone includes: calcining the limestone, mixing and reacting it with nano-silica, then subjecting it to steam treatment and carbonation.

[0122] Specifically, the modification treatment of the limestone includes: calcining the limestone at 800-900℃ for 2-3 hours, cooling it and mixing it with nano-silica, reacting the mixed powder at 600-700℃ for 1.5-2 hours, cooling it and reacting it in a water vapor atmosphere for 2-3 hours, and then carbonating it in a CO2 atmosphere at 400-500℃ for 1-2 hours to obtain the modified limestone.

[0123] The mass ratio of the limestone to the nano-silica can be 1:1 to 3, that is, the mass of the limestone to the mass of the nano-silica = 1:1 to 3, specifically 1:1 to 1.5, 1:1.5 to 2, 1:2 to 2.5, 1:2.5 to 3, etc.

[0124] In this embodiment, the limestone is calcined to obtain CaO. Nano-SiO2 and CaO undergo a mixed reaction at high temperature. The two interact with each other, thereby increasing the diffusion rate of CO2 into the small pores of the limestone during subsequent carbonation treatment, which improves the stability of the modified limestone pore structure. After the limestone is treated with water vapor, the water vapor reacts with CaO to generate Ca(OH)2. After carbonation in a CO2 atmosphere, CaCO3 is formed, which is beneficial to the stable precipitation of minerals in the modified limestone.

[0125] In one embodiment, the limestone is a natural limestone. Specifically, the limestone is the Maokou Formation limestone of the Permian system in Emeishan, and its main minerals are calcite, with minor amounts of quartz and clay minerals.

[0126] In one embodiment, the limestone has a particle size range of 35 to 200 mesh, specifically obtained by crushing natural limestone. The method for crushing the limestone is a method known in the art for crushing rocks.

[0127] In one specific embodiment, the modified limestone preparation method is as follows: after cleaning the limestone, it is crushed into powder of 35-200 mesh. The limestone powder is calcined at 800-900℃ for 3 hours. After cooling, it is mixed with nano-silica (SiO2) in a ratio of limestone:SiO2 of 1:1-3. The mixed powder is placed in a muffle furnace and reacted at 600-700℃ for 2 hours. After cooling, it is reacted in a steam atmosphere for 2 hours, and then transferred to a 100% CO2 atmosphere at 450℃ for 1 hour for carbonation. Finally, it is cooled to room temperature in a CO2 atmosphere to obtain the modified limestone.

[0128] In step S12:

[0129] In one embodiment, the activated carbon can be selected from coconut shell activated carbon. Coconut shell activated carbon is activated carbon produced from coconut shell raw materials, and has characteristics such as high strength, regeneration after saturation, high adsorption capacity, and low resistance. The activated carbon has good adsorption properties and can work synergistically with modified volcanic breccia, modified basalt, modified dolomite, modified limestone, etc., to adsorb and remove impurities in drinking water. Furthermore, it can precipitate various minerals through ion exchange, thereby simulating the drinking water quality of Emei Mountain groundwater by using the filter element.

[0130] Specifically, the particle size range of the activated carbon can be 10-200 mesh, such as 10-30 mesh, 30-50 mesh, 50-80 mesh, 80-200 mesh, 80-100 mesh, 100-120 mesh, 120-150 mesh, 150-180 mesh, 180-200 mesh, etc.

[0131] In one embodiment, the activated carbon, the polymer, the modified volcanic breccia, the modified basalt, the modified dolomite, and the modified limestone are mixed. Specifically, the mixture is prepared by mixing 25-40 parts by weight of the activated carbon, 25-50 parts by weight of the polymer, 5-10 parts by weight of the modified volcanic breccia, 10-25 parts by weight of the modified basalt, 10-25 parts by weight of the modified dolomite, and 10-20 parts by weight of the modified limestone to obtain the mixture.

[0132] In this embodiment, the filter element formed by mixing the components within the specified content range can produce drinking water with a quality simulating that of groundwater from Mount Emei when filtering drinking water. Furthermore, the modified volcanic breccia, modified basalt, modified dolomite, and modified limestone can firmly adhere to the polymer, preventing the high turbidity and color of the water caused by the dissolution and dispersion of these materials. It also avoids filter element clogging due to a high polymer content.

[0133] In step S13, the mixture can be poured into a mold, pressed into shape, fired and demolded, cooled and then cut to obtain the formed filter element.

[0134] Specifically, the firing temperature can be 175–195°C, and the firing time can be 1–1.5 h.

[0135] This application also provides a filter. Referring to Figure 3, Figure 3 is a structural schematic diagram of an embodiment of the filter provided in this application. The filter 100 includes a filter element 10, which can be a filter element simulating the groundwater quality of Mount Emei provided in this application, or a filter element prepared by the method for preparing a filter element simulating the groundwater quality of Mount Emei provided in this application. By using the filter 100 to treat drinking water, the groundwater quality of Mount Emei can be simulated, and drinking water with a quality close to that of the groundwater of Mount Emei can be obtained.

[0136] Furthermore, the filter 100 also includes a housing 30 and two end caps 20. The filter element 10 has a hollow cylindrical structure, and the end caps 20 are respectively placed over both ends of the filter element 10. The filter element is placed inside the housing 30. The arrows indicate the direction of water flow.

[0137] The present application will be specifically described below through specific embodiments. The following embodiments are only some embodiments of the present application and are not intended to limit the present application.

[0138] Example 1

[0139] This embodiment provides a filter element and its preparation method, specifically including:

[0140] Preparation of modified volcanic breccia:

[0141] After cleaning the natural volcanic breccia, it is crushed into small particles of 1-5 mm, soaked in a 10% sulfuric acid solution for 2 hours, filtered out, and repeatedly rinsed with distilled water. It is then dried thoroughly at 105°C, placed in a muffle furnace at 200°C for 30 minutes, cooled, and pulverized with a pulverizer. The resulting powder is screened to a mesh size of 35-100, thus obtaining the modified volcanic breccia.

[0142] Preparation of modified basalt:

[0143] After cleaning the natural basalt, it is crushed into small particles of 1-5 mm. It is first soaked in 5% hydrogen peroxide solution and shaken at 60°C for 24 hours. After that, it is taken out, washed and dried. Then it is soaked in 1 mol / L sodium hydroxide solution, sealed with plastic wrap during the soaking process, stirred in a water bath at 75°C for 2 hours, and sonicated for 1 hour. After that, it is taken out, washed, dried and cooled, and then crushed with a pulverizer. The powder is screened into 60-200 mesh to obtain modified basalt.

[0144] Preparation of modified dolomite:

[0145] After cleaning the natural dolomite, it is crushed into powder of 35-100 mesh. The powder is then immersed in a NaNO3 solution with a mass ratio of dolomite to NaNO3 of 0.2:1. The mixture is stirred at 80°C for 15 minutes, dried at 120°C for 2 hours, activated at 500°C for 2 hours under a nitrogen atmosphere, cooled, and then carbonated in a 100% CO2 atmosphere. The temperature is then increased from room temperature to 400°C at a rate of 6°C / min, maintained at 400°C for 60 minutes, and finally cooled to room temperature in a CO2 atmosphere to obtain the modified dolomite.

[0146] Preparation of modified limestone:

[0147] After cleaning the natural limestone, it is crushed into powder of 35-200 mesh. The powder is calcined at 800℃ for 3 hours, cooled, and then mixed with nano-silica in a ratio of limestone to SiO2 of 1:2. The mixed powder is placed in a muffle furnace and reacted at 600℃ for 2 hours. After cooling, it is reacted in a steam atmosphere for 2 hours, then transferred to a 100% CO2 atmosphere at 450℃ for 1 hour for carbonation, and finally cooled to room temperature in a CO2 atmosphere to obtain modified limestone.

[0148] Filter element preparation

[0149] Weigh out 10g of the modified volcanic breccia, 20g of the modified dolomite, 20g of the modified limestone, 20g of the modified basalt, 70g of coconut shell activated carbon, and 70g of high-molecular-weight polyethylene, mix them thoroughly, pour the mixture into a mold, press it into shape, fire it to demold it, cool it, and cut it to make filter elements with dimensions of 45 (outer diameter) * 22 (inner diameter) * 203 (length) mm, with each 2g serving as one sample. Three parallel samples were prepared for the filter elements obtained in Example 1, namely No. 1, No. 2, and No. 3.

[0150] Total pore volume, average pore size, and specific surface area were measured for both the unmodified volcanic breccia (i.e., natural volcanic breccia) and the modified volcanic breccia from Example 1. The testing method used a Micron ASAP2460 specific surface area and porosity analyzer. The test results are shown in Table 1.

[0151] Table 1. Summary of pore volume and specific surface area of ​​volcanic breccia samples before and after modification.

[0152] Rock sample number Total pore volume (cm³) 3 / g) Average pore size (nm) Specific surface area (m²) 2 / g) Unmodified volcanic breccia 1.381×10 -3 10.21620.518 Modified volcanic breccia 9.098×10 -3 10.5072.145 surface

[0153] As shown in Table 1, compared with the unmodified volcanic breccia, the modified volcanic breccia has a significantly increased pore volume and specific surface area, and the average pore size has increased to a certain extent, thereby improving the ion exchange performance of the modified volcanic breccia.

[0154] SEM tests were performed on the unmodified basalt (i.e., natural basalt) and modified basalt from Example 1, respectively, yielding SEM images of the unmodified basalt (see Figure 4) and modified basalt (see Figure 5). The SEM tests were conducted using a Zeiss Gemini 300 scanning electron microscope. As shown in Figures 4 and 5, compared to the unmodified basalt, the modified basalt has a rougher surface and more pores, which facilitates water-rock interaction.

[0155] Total pore volume, average pore diameter, and specific surface area were measured for both the unmodified dolomite (i.e., natural dolomite) and the modified dolomite from Example 1. The testing method used a Micron ASAP2460 specific surface area and porosity analyzer. The test results are shown in Table 2.

[0156] Table 2. Summary of pore volume and specific surface area of ​​dolomite samples before and after modification.

[0157] Rock sample number Total pore volume (cm³) 3 / g) Average pore size (nm) Specific surface area (m²) 2 / g) Unmodified dolomite 2.765×10 -3 4.0392.738 Modified dolomite 1.047×10 -2 7.4645.609 surface

[0158] As shown in Table 2, compared with unmodified dolomite, modified dolomite has a significantly larger average pore size and specific surface area, which is conducive to the stable precipitation of minerals in modified dolomite.

[0159] SEM tests were performed on the unmodified dolomite (i.e., natural dolomite) and modified dolomite from Example 1, respectively, yielding SEM images of the unmodified dolomite (see Figure 6) and the modified dolomite (see Figure 7). The SEM tests were conducted using a Zeiss Gemini 300 scanning electron microscope. As shown in Figures 6 and 7, compared to the unmodified dolomite, the modified dolomite has a rougher surface and larger pores, which is beneficial for the stable precipitation of minerals from the modified dolomite.

[0160] EDS analysis was performed on the unmodified and modified limestone in Example 1 to obtain the elemental composition of the unmodified and modified limestone (see Table 3). The EDS analysis was performed using a Zeiss Gemini 300 scanning electron microscope.

[0161] Table 3. A list of atomic percentages of various elements in limestone before and after modification.

[0162] Elemental modification of limestone: Before modification: C 18.1722.19; O 59.857.4; Mg 1.551.27; Ca 20.1715; Si 0.3415 surface

[0163] As shown in Table 3, compared with the unmodified limestone, the content of C and Si in the modified limestone increases, while the content of Mg, Ca and O decreases. The modified limestone is still dominated by CaCO3, but a small amount of SiO2 enters the limestone, which improves the stability of the pore structure of the modified limestone.

[0164] SEM tests were performed on the unmodified and modified limestone from Example 1, resulting in SEM images of the unmodified limestone (see Figure 8) and the modified limestone (see Figure 9). The SEM tests were conducted using a Zeiss Gemini 300 scanning electron microscope. As shown in Figures 8 and 9, compared to the unmodified limestone, the modified limestone has a rougher surface and a larger surface area, which is beneficial for the stable precipitation of minerals from the modified limestone.

[0165] In accordance with the requirements of the "Standard for Hygiene and Safety Evaluation of Drinking Water Transmission and Distribution Equipment and Protective Materials", the filter elements of Example 1 (No. 1, No. 2 and No. 3 respectively) were subjected to a hygiene and safety immersion test. The immersion results are shown in Table 4.

[0166] Table 4: Immersion results of the filter element prepared in Example 1

[0167]

[0168] The immersion solution served as a control test, and was prepared according to the method in Appendix A of the "Standard for Hygienic Safety Evaluation of Drinking Water Transmission and Distribution Equipment and Protective Materials" (2001). As shown in Table 4, the hygienic safety of the simulated Emei Mountain mineral water filter element prepared by this invention meets the requirements of the "Standard for Hygienic Safety Evaluation of Drinking Water Transmission and Distribution Equipment and Protective Materials" (2001).

[0169] Example 2

[0170] This embodiment is basically the same as Embodiment 1, except that in the preparation process of the filter element in this embodiment, 15g of modified volcanic breccia, 30g of modified dolomite, 30g of modified limestone, 30g of modified basalt, 120g of coconut shell activated carbon, and 120g of high molecular weight polyethylene were weighed, stirred evenly, poured into a mold, pressed and shaped, fired and demolded, cooled and cut into 10-inch filter elements, with each 3g portion. The obtained 10-inch filter elements were installed at the end of a pure water machine for continuous water flow at a flow rate of 1.6-2.0L / min. Samples of filtered water were taken at flow rates of 1000L, 2000L, 3000L, 4000L, and 5000L to test the concentrations of pH, calcium, magnesium, zinc, strontium, and bicarbonate. The test results are shown in Table 5.

[0171] Table 5: Water flow test results of the filter cartridge prepared in Example 2

[0172]

[0173] Note: ND indicates not detected.

[0174] As shown in Table 5, compared with pure water, the pH of the filter cartridge produced in this application remains stable in the slightly alkaline range of 7.0–8.5, and the concentrations of minerals such as calcium, magnesium, zinc, strontium, and bicarbonate are significantly increased. The quality of the filter cartridge's effluent is similar to that of Emei Mountain mineral water, both being HCO3-Ca·Mg or HCO3-Ca type water, and containing trace elements boron and zinc that are beneficial to the human body.

[0175] The filter element provided in this application can produce drinking water that simulates the quality of groundwater from Mount Emei, and it reduces costs compared to bottled water from Mount Emei.

[0176] The above provides a detailed description of the filter element, preparation method, and filter for simulating groundwater quality in Mount Emei provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A filter element that simulates the groundwater quality of Mount Emei, characterized in that, include: The mixture comprises modified volcanic breccia, modified basalt, modified dolomite, modified limestone, activated carbon, and polymers; wherein the volcanic breccia is soaked in an acidic solution, and the resulting solid is calcined at 200-300℃ for 30-60 minutes to obtain the modified volcanic breccia; the basalt is mixed in an oxidizing solution, and then the resulting solid is mixed in an alkaline solution to obtain the modified basalt. Dolomite is impregnated in a molten salt solution, stirred at 75-85°C for 15-20 min, and dried at 110-120°C for 1.5-2 h. The resulting solid is then activated in an inert atmosphere at 450-550°C for 2-3 h, cooled, and then heated in a CO2 atmosphere at a heating rate of 6-8°C / min to 350-400°C. This temperature is maintained for 30-90 min to perform carbonation modification, yielding the modified dolomite. Limestone is calcined at 800-900°C for 2-3 h, cooled, and mixed with nano-silica. The mixed powder is reacted at 600-700°C for 1.5-2 h, cooled, and then reacted in a steam atmosphere for 2-3 h. Finally, it is carbonated in a CO2 atmosphere at 400-500°C for 1-2 h to obtain the modified limestone. The polymer is selected from at least one of polypropylene, polyethylene, polyvinyl alcohol, and polytetrafluoroethylene.

2. The filter element according to claim 1, characterized in that, By weight, the filter element comprises: 5-10 parts of modified volcanic breccia, 10-25 parts of modified basalt, 10-25 parts of modified dolomite, 10-20 parts of modified limestone, 25-40 parts of activated carbon, and 25-50 parts of polymer.

3. The filter element according to claim 1, characterized in that, The modified volcanic breccia is volcanic breccia that has been acid-modified and then calcined; and / or the particle size range of the modified volcanic breccia is 35-100 mesh; and / or the particle size range of the modified basalt is 60-200 mesh; and / or the activated carbon is selected from coconut shell activated carbon.

4. A method for preparing a filter element that simulates the groundwater quality of Mount Emei, characterized in that, include: The system provides volcanic breccia, basalt, dolomite, and limestone, and modifies each of these materials to obtain modified volcanic breccia, modified basalt, modified dolomite, and modified limestone. It also provides activated carbon and a polymer, and mixes the activated carbon, the polymer, the modified volcanic breccia, the modified basalt, the modified dolomite, and the modified limestone to obtain a mixture. The mixture is then calcined to obtain the filter element. The modification method for the volcanic breccia involves soaking it in an acidic solution and then calcining the resulting solid at 200-300°C for 30-60 minutes to obtain the modified volcanic breccia. The modification method for the basalt involves mixing it in an oxidizing solution and then mixing the resulting solid in an alkaline solution to obtain the modified basalt. The modification method for the dolomite involves... The dolomite was impregnated in a molten salt solution, stirred at 75-85°C for 15-20 min, and dried at 110-120°C for 1.5-2 h. The resulting solid was then activated in an inert atmosphere at 450-550°C for 2-3 h. After cooling, it was placed in a CO2 atmosphere and heated to 350-400°C at a heating rate of 6-8°C / min, and held at this temperature for 30-90 min for carbonation modification to obtain the modified dolomite. The method for modifying limestone is as follows: the limestone is calcined at 800~900℃ for 2~3h, cooled and mixed with nano-silica, the mixed powder is reacted at 600~700℃ for 1.5~2h, cooled and reacted in a water vapor atmosphere for 2~3h, and then carbonated in a CO2 atmosphere at 400~500℃ for 1~2h to obtain the modified limestone; the polymer is selected from at least one of polypropylene, polyethylene, polyvinyl alcohol and polytetrafluoroethylene.

5. The preparation method according to claim 4, characterized in that, The volcanic breccia is the Permian volcanic breccia of Mount Emei; and / or the grain size range of the volcanic breccia is 1-5 mm; and / or the basalt is the Permian Emeishan basalt, and the basalt is amygdaloidal basalt; and / or the grain size range of the basalt is 1-5 mm; and / or the dolomite is the Silurian dolomite of Mount Emei; and / or the grain size range of the dolomite is 35-100 mesh; and / or the limestone is the Permian Maokou Formation limestone of Mount Emei; and / or the grain size range of the limestone is 35-200 mesh; and / or the activated carbon is selected from coconut shell activated carbon.

6. The preparation method according to claim 5, characterized in that, The modified volcanic breccia has a grain size range of 35-100 mesh; and / or the modified basalt has a grain size range of 60-200 mesh.

7. The preparation method according to claim 6, characterized in that, The acidic solution is selected from at least one of sulfuric acid aqueous solution, hydrochloric acid aqueous solution, and nitric acid aqueous solution; and / or the oxidizing solution is selected from hydrogen peroxide solution; and / or the alkaline solution is selected from at least one of sodium hydroxide solution, potassium hydroxide solution, and ammonia solution; and / or the molten salt solution comprises molten salt and water, wherein the mass ratio of the molten salt to the dolomite is 0.1~0.3:1; and / or the molten salt is selected from one or more of NaNO3 or KNO3 and LiNO3; and / or the mass ratio of the limestone to the nano-silica is 1:1~3.

8. The preparation method according to claim 7, characterized in that, The acidic solution is selected from a sulfuric acid aqueous solution with a volume fraction of 10%~15%, or a hydrochloric acid aqueous solution with a concentration of 0.5~1mol / L, or a nitric acid aqueous solution with a concentration of 0.5~1mol / L; and / or the volcanic breccia is immersed in the acidic solution for 2~3 hours; and / or the oxidizing solution has a mass percentage concentration of 5~8%; and / or the alkaline solution has a concentration of 0.5~1.5mol / L; and / or the temperature at which the basalt is mixed and treated in the oxidizing solution. The temperature is 55~65℃, and the time is 20~30h; and / or the mixing method of placing the basalt in an oxidizing solution is one or more of shaking, stirring, or rotating mixing; and / or in the method of modifying the basalt, the temperature of placing the obtained solid in an alkaline solution is 70~80℃, and the time is 2~3h; and / or in the method of modifying the basalt, the mixing method of placing the obtained solid in an alkaline solution is stirring first, and then sonicating.

9. The preparation method according to claim 4, characterized in that, The method of mixing the activated carbon, the polymer, the modified volcanic breccia, the modified basalt, the modified dolomite, and the modified limestone to obtain a mixture comprises: mixing 25-40 parts by mass of the activated carbon, 25-50 parts by mass of the polymer, 5-10 parts by mass of the modified volcanic breccia, 10-25 parts by mass of the modified basalt, 10-25 parts by mass of the modified dolomite, and 10-20 parts by mass of the modified limestone to obtain the mixture.

10. A filter, characterized in that, The filter includes a filter element simulating the groundwater quality of Mount Emei as described in any one of claims 1 to 3, or a filter element prepared by the method for preparing a filter element simulating the groundwater quality of Mount Emei as described in any one of claims 4 to 9.

11. The filter according to claim 10, characterized in that, The filter further includes a housing and two end caps. The filter element has a hollow cylindrical structure. The end caps are respectively placed over both ends of the filter element, and the filter element is placed inside the housing.

Images