Drinking water purification filter element made of brown jade and preparation method of drinking water purification filter element

Abstract

The invention relates to the technical field of drinking water purification filter elements, in particular to a spring jade drinking water purification filter element and a preparation method thereof.The spring jade drinking water purification filter element comprises clamps, the clamps are installed at the upper end and the lower end of a filter element shell, and sealing rings are installed at the upper end and the lower end of the outer side of the filter element shell; a mechanical pre-filtering layer, an activated carbon adsorption layer, a heavy metal removal layer, a jade photocatalysis layer, an ultrafiltration precision layer and a rear polishing layer are sequentially mounted on the inner side of the filter element shell from top to bottom; the filter element shell comprises a cylindrical shell, annular grooves are formed in the outer sides of the upper end and the lower end of the cylindrical shell, mounting grooves are formed in the inner sides of the upper end and the lower end of the cylindrical shell, and a spiral flow guide groove is formed in the inner side of the upper end of the cylindrical shell; according to the invention, filtering can be synchronously carried out from the upper end and the middle part of the laminated filter screen plate, and when the upper end is blocked, the filtering effect and efficiency can still be ensured, so that the laminated filter screen plate can be fully utilized, the replacement period of the mechanical pre-filtering layer is effectively prolonged, and a good economic effect is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of drinking water purification filters, and specifically to a Xuanhuangyu drinking water purification filter and a preparation method thereof. Background Art

[0002] The Xuanhuangyu drinking water purification filter is an innovative water filtration device that combines traditional filtration technologies and the natural purification characteristics of Xuanhuangyu. The internal structure of the filter usually includes multiple layers of filtration media such as PP cotton, activated carbon, and ion exchange resin, which are used to remove impurities, residual chlorine, odors, and harmful ions in water. Among them, the Xuanhuangyu layer is the core part, which can effectively adsorb heavy metal ions (such as lead, mercury, cadmium, etc.) and micro plastic particles in water. These harmful substances are difficult to be completely removed by conventional filtration methods. In addition, the filter design may also include photocatalytic materials to further decompose organic pollutants by sunlight irradiation. Generally speaking, the Xuanhuangyu drinking water purification filter provides purer and safer drinking water through multi-stage filtration and the adsorption of natural minerals, which helps to improve water quality and protect the health of users. In the process of preparing a drinking water purification filter with Xuanhuangyu, the first layer of filtration is generally used to filter larger particles in the water quality. During the filtration process, the filtration layer set near the filtration water inlet has a relatively large filtration pressure. When the filter screen in this part is blocked, it will affect the filtration efficiency, and seriously affect the filtration effect, and the whole needs to be replaced. The replacement cycle is relatively short. Therefore, a Xuanhuangyu drinking water purification filter and a preparation method thereof are proposed to solve the above problems. Summary of the Invention

[0003] The purpose of the present invention is to provide a Xuanhuangyu drinking water purification filter and a preparation method thereof, so as to solve the problem that in the process of preparing a drinking water purification filter with Xuanhuangyu, the first layer of filtration is generally used to filter larger particles in the water quality. During the filtration process, the filtration layer set near the filtration water inlet has a relatively large filtration pressure. When the filter screen in this part is blocked, it will affect the filtration efficiency, and seriously affect the filtration effect, and the whole needs to be replaced. The replacement cycle is relatively short.

[0004] To achieve the above purpose, the present invention provides the following technical solutions: A Xuanyuan jade drinking water purification filter element and its preparation method, including a clamp, the clamp is installed at the upper and lower ends of the filter element housing, sealing rings are installed at the upper and lower outer sides of the filter element housing, and a mechanical pre-filter layer, an activated carbon adsorption layer, a heavy metal removal layer, a Xuanyuan jade photocatalytic layer, an ultrafiltration precision layer and a post-polishing layer are installed in the filter element housing from top to bottom in sequence; the filter element housing includes a columnar housing, annular grooves are opened on the outer sides of the upper and lower ends of the columnar housing, installation grooves are opened on the inner sides of the upper and lower ends of the columnar housing, and a spiral diversion groove is opened on the inner side of the upper end of the columnar housing; the mechanical pre-filter layer includes a positioning frame, a plurality of through holes distributed annularly are opened on the inner sides of the upper and lower ends of the positioning frame, and a laminated filter mesh plate is installed on the outer side of the middle of the positioning frame; the Xuanyuan jade photocatalytic layer includes a sealing housing, filter circular plates are fixedly connected to the inner sides of the upper and lower ends of the sealing housing, Xuanyuan jade ceramic microspheres are placed between the filter circular plates, and a surface-loaded antibacterial photocatalyst TiO is uniformly distributed inside the Xuanyuan jade ceramic microspheres 2 。

[0005] As a further optimized content of the present invention, wherein: the outer side of the columnar housing is connected to the sealing ring through the opened annular groove, the annular groove and the sealing ring correspond to each other one by one, the inner side of the columnar housing is connected to the clamp through the opened installation groove, the installation groove and the clamp correspond to each other one by one, and the height of the spiral diversion groove is one-half of the height of the mechanical pre-filter layer.

[0006] As a further optimized content of the present invention, wherein: the clamp includes an open ring, disassembly holes are opened at both ends of the opening of the open ring, and anti-slip grooves distributed annularly are opened on the inner wall of the disassembly hole.

[0007] As a further optimized content of the present invention, wherein: the horizontal projection of the positioning frame is H-shaped, the lower half of the laminated filter mesh plate is in close contact with the inner wall of the columnar housing, the laminated filter mesh plate is made of porous PP cotton, and the pore diameter of the laminated filter mesh plate is 5-10 μm.

[0008] As a further optimized content of the present invention, wherein: the activated carbon adsorption layer is coconut shell activated carbon particles, and the particle size of the coconut shell activated carbon particles is 0.7-1.7 mm.

[0009] As a further optimized content of the present invention, wherein: the heavy metal removal layer is made of crosslinked polymer ion exchange resin.

[0010] As a further optimized content of the present invention, wherein: micropores are opened inside the Xuanyuan jade ceramic microspheres, and the pore diameter of the micropores opened inside the Xuanyuan jade ceramic microspheres is 0.2-1 μm.

[0011] As a further optimized content of the present invention, wherein: the ultrafiltration precision layer is made by laminating ceramic composite ultrafiltration membranes, and the pore size of the ceramic composite ultrafiltration membrane is 0.01 μm.

[0012] As a further optimized content of the present invention, wherein: the post - polishing layer includes a plastic shell arranged in a columnar shape, a spiral deflector is installed inside the plastic shell, and food - grade aromatic activated carbon powder is evenly attached to the upper surface of the spiral deflector.

[0013] As a further optimized content of the present invention, wherein: Step 1: Filter element housing and pretreatment: Select food - grade polypropylene pipes to process into filter element housings with the required diameter, and reserve positioning bosses on the inner wall to fix various filter materials. All plastic parts are first ultrasonically cleaned to remove oil stains and impurities, and then dried in an oven at 60 °C for 2 hours; Step 2: Filling of the mechanical pre - filtration layer: Cut the porous PP cotton that has been screened and dedusted into sheets matching the inner diameter of the filter element, and fill it into the outside of the positioning frame in two layers in the order of "bottom first and top last". The filling height is controlled at 15 - 20 mm, and it is gently pressed with a special pressing rod to make the cotton layer flat, tight, and without obvious gaps; Step 3: Construction of the activated carbon adsorption layer: Wash the coconut shell activated carbon particles with a particle size of 0.7 - 1.7 mm with deionized water until clear, dry them at 120 °C for 4 hours, take the dry particles and fill them into the middle section of the filter element to a height of about 25 mm by volume, add them in batches and cooperate with mild vibration to eliminate voids; Step 4: Preparation of the heavy - metal removal layer and the xuanyu jade photocatalytic layer: First, mix strong - acid cation exchange resin and strong - base anion exchange resin in a volume ratio of 1:1, activate them with 0.5M NaCl solution for 4 hours and rinse until the conductivity < 5 μS / cm; At the same time, immerse xuanyu jade ceramic balls with a pore size of 0.2 - 1 μm in 3wt% TiO 2 nanoslurry, dry them and sinter them at 800 °C for 2 hours to load the photocatalytic layer. Then, first fill a 20 - mm ion - exchange resin layer, then lay a 20 - mm xuanyu jade photocatalytic ball layer, and install a polypropylene spacer between the two layers to avoid displacement. The whole xuanyu jade photocatalytic layer is installed between the filter discs; Step 5: Encapsulation of the ultrafiltration precision layer: Prepare ceramic composite ultrafiltration membrane discs with a pore size of 0.01 µm, seal the edges with food - grade epoxy resin or hot - melt gaskets and install them in the special card slots in the middle section of the filter element, gently press and position them and make a circular anti - leakage seal. After installation, back - flush with pure water for 10 minutes, and confirm that the water flux ≥ 1.5 L / min at 0.2 MPa; Step 6: Preparation of the post - polishing layer: Fill activated carbon powder that has passed through a 200 - mesh sieve and has a specific surface area > 800 m² / g to a thickness of about 5 mm at the upper end of the spiral deflector, and install another piece of PP cotton on the top layer to fix it; Step 7: Overall assembly: Install the mechanical pre-filter layer, activated carbon adsorption layer, heavy metal removal layer, xuanyu jade photocatalytic layer, ultrafiltration precision layer, and post-polishing layer from top to bottom inside the filter element housing in sequence through clamps to complete the assembly.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. In the present invention, through the arranged spiral diversion layer and mechanical pre-filter layer, filtration can be carried out synchronously from the upper end and the middle part of the laminated filter mesh plate. When the upper end is blocked, the filtration effect and efficiency can still be ensured, and thus the laminated filter mesh plate can be fully utilized, effectively increasing the replacement cycle of the mechanical pre-filter layer and having good economic benefits. 2. In the present invention, through the cooperation of the mechanical pre-filter layer, activated carbon adsorption layer, heavy metal removal layer, xuanyu jade photocatalytic layer, ultrafiltration precision layer, and post-polishing layer, and by combining the natural porous characteristics of xuanyu jade with modern photocatalytic technology, heavy metals and microplastics can be removed efficiently and safely, ensuring the cleanliness and health of the final drinking water. 3. In the present invention, a systematic and modular preparation process is adopted to standardize the splitting and combination of each process step, making the production process clearer and more orderly: on the one hand, each module can be assembled in parallel or in series, significantly shortening the production cycle and reducing labor costs; on the other hand, through unified process parameters and quality inspection standards, large-scale stable output of product performance and consistency is achieved; at the same time, each core component is designed modularly, and there is no need to disassemble the whole when maintaining and replacing, effectively reducing the maintenance difficulty and downtime, and greatly improving the convenience of batch manufacturing and later operation and maintenance. Description of the Drawings

[0015] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a schematic diagram of the internal structure of the filter element housing of the present invention; Figure 3 It is a schematic diagram of the position structure where the spiral diversion groove of the present invention is opened; Figure 4 It is a schematic diagram of the position structure where the sealing ring of the present invention is installed; Figure 5 It is a schematic diagram of the mechanical pre-filter layer of the present invention; Figure 6 It is a schematic diagram of the positioning frame of the present invention; Figure 7 It is a schematic diagram of the xuanyu jade photocatalytic layer of the present invention; Figure 8 It is a cross-sectional view of the post-polishing layer of the present invention.

[0016] In the figure: 1. Filter element housing; 11. Column shell; 12. Ring groove; 13. Spiral diversion groove; 14. Installation groove; 2. Clamp; 21. Split ring; 22. Demounting hole 3. Mechanical pre-filter layer; 31. Positioning frame; 32. Through hole; 33. Stacked filter mesh plate 4. Sealing ring; 5. Activated carbon adsorption layer; 6. Heavy metal removal layer 7. Xuanyuan jade photocatalytic layer; 71. Sealed housing; 72. Filter round plate 8. Ultrafiltration precision layer 9. Post-polishing layer; 91. Plastic shell; 92. Spiral flow guide plate Detailed implementation mode

[0017] Please refer to Figure 1-8 , the present invention provides a technical solution: A Xuanyuan jade drinking water purification filter element and its preparation method, including a clamp 2, the clamp 2 is installed at the upper and lower ends of the filter element housing 1, sealing rings 4 are installed at the upper and lower ends of the outer side of the filter element housing 1, and a mechanical pre-filter layer 3, an activated carbon adsorption layer 5, a heavy metal removal layer 6, a Xuanyuan jade photocatalytic layer 7, an ultrafiltration precision layer 8 and a post-polishing layer 9 are installed in the filter element housing 1 from top to bottom in sequence; the filter element housing 1 includes a column shell 11, annular grooves 12 are opened on the outer sides of the upper and lower ends of the column shell 11, installation grooves 14 are opened on the inner sides of the upper and lower ends of the column shell 11, and a spiral flow guide groove 13 is opened on the inner side of the upper end of the column shell 11; the mechanical pre-filter layer 3 includes a positioning frame 31, a plurality of through holes 32 distributed annularly are opened on the inner sides of the upper and lower ends of the positioning frame 31, and a stacked filter mesh plate 33 is installed on the outer side of the middle of the positioning frame 31; the Xuanyuan jade photocatalytic layer 7 includes a sealed housing 71, filter round plates 72 are fixedly connected to the inner sides of the upper and lower ends of the sealed housing 71, Xuanyuan jade ceramic microspheres are placed between the filter round plates 72, and surface-loaded antibacterial photocatalyst TiO is evenly distributed inside the Xuanyuan jade ceramic microspheres 2 .

[0018] As a further implementation technical solution of this scheme, the outer side of the column shell 11 is connected to the sealing ring 4 through the opened annular groove 12, the annular groove 12 and the sealing ring 4 correspond to each other one by one, the inner side of the column shell 11 is connected to the clamp 2 through the opened installation groove 14, the installation groove 14 and the clamp 2 correspond to each other one by one, the height of the spiral flow guide groove 13 is one-half of the height of the mechanical pre-filter layer 3, the annular groove 12 and the sealing ring 4 can ensure the sealing effect of the external installation, the clamp 2 can stably install the mechanical pre-filter layer 3, the activated carbon adsorption layer 5, the heavy metal removal layer 6, the Xuanyuan jade photocatalytic layer 7, the ultrafiltration precision layer 8 and the post-polishing layer 9 inside the filter housing 1, and the spiral flow guide groove 13 can evenly disperse the incoming water, ensuring the use efficiency and service life of the mechanical pre-filter layer 3; As a further technical solution for the implementation of this solution, the clamp 2 includes an opening ring 21. Disassembly holes 22 are provided at both ends of the opening of the opening ring 21. Anti-slip grooves are provided on the inner wall of the disassembly holes 22 and are distributed in a ring shape. The opening ring 21 is designed in cooperation with the disassembly holes 22, and a special tool can be used to quickly lock or loosen the clamp; the anti-slip grooves improve the gripping force during disassembly and facilitate installation and maintenance; As a further technical solution for the implementation of this solution, the horizontal projection of the positioning frame 31 is in the shape of an "H". The lower half of the laminated filter mesh plate 33 is in close contact with the inner wall of the columnar shell 11. The laminated filter mesh plate 33 is made of porous PP cotton, and the pore diameter of the laminated filter mesh plate 33 is 5-10 μm. The "H"-shaped positioning frame 31 ensures that the laminated filter mesh plate 33 is stable and does not shift. The porous PP cotton accurately intercepts 5-10 μm suspended particles, protecting the subsequent filter layer from being blocked by large particles; As a further technical solution for the implementation of this solution, the activated carbon adsorption layer 5 is made of coconut shell activated carbon particles, and the particle size of the coconut shell activated carbon particles is 0.7-1.7 mm. The 0.7-1.7 mm coconut shell activated carbon takes into account a high specific surface area and low resistance, can efficiently adsorb residual chlorine, organic substances and odors, and at the same time maintain a reasonable flow rate; As a further technical solution for the implementation of this solution, the heavy metal removal layer 6 is made of crosslinked polymer ion exchange resin. The crosslinked ion exchange resin can selectively exchange heavy metal ions such as Pb²⁺, Cd²⁺, Hg²⁺, etc., ensuring that the heavy metal removal rate is as high as over 95%; As a further technical solution for the implementation of this solution, the micro-pores are provided inside the Xuanyuan jade ceramic microspheres, and the pore diameter of the micro-pores provided inside the Xuanyuan jade ceramic microspheres is 0.2-1 μm. The 0.2-1 μm micro-pore structure provides a large surface area carrier for the TiO 2 photocatalyst, effectively improving the decomposition efficiency of micro-organic pollutants and the flocculation removal efficiency of micro-plastics; As a further technical solution for the implementation of this solution, the ultrafiltration precision layer 8 is made by laminating ceramic composite ultrafiltration membranes. The pore diameter of the ceramic composite ultrafiltration membrane is 0.01 μm. The 0.01 μm ultrafiltration membrane can completely intercept residual micro-plastic particles, bacteria and most viruses, ensuring high safety of the effluent; As a further technical solution for the implementation of this solution, the post-polishing layer 9 includes a plastic shell 91 arranged in a column shape. A spiral flow guide plate 92 is installed inside the plastic shell 91. Food-grade aromatic activated carbon powder is evenly attached to the upper surface of the spiral flow guide plate 92. The spiral flow guide plate prolongs the residence time of the water flow in the polishing layer, evenly contacts the activated carbon powder, further removes trace odors and improves the taste; As a further technical solution for the implementation of this solution, Step 1: Filter element housing 1 and pretreatment: Select food-grade polypropylene pipes to process the filter element housing 1 with the required diameter, and reserve positioning bosses on the inner wall to fix various filter materials. All plastic parts are first ultrasonically cleaned to remove oil stains and impurities, and then dried in an oven at 60 °C for 2 hours; Step 2: Filling of the mechanical pre-filter layer 3: Cut the porous PP cotton that has been screened and dust-removed into sheets matching the inner diameter of the filter element, and fill it outside the positioning frame 31 in two layers in the order of "bottom first and top last". The filling height is controlled at 15-20 mm, and it is gently pressed with a special pressing rod to make the cotton layer flat, tight, and without obvious gaps; Step 3: Construction of the activated carbon adsorption layer 5: Wash the coconut shell activated carbon particles with a particle size of 0.7-1.7 mm with deionized water until it is clear, dry it at 120 °C for 4 hours, take the dry particles and fill them into the middle section of the filter element to a height of about 25 mm in batches, and add them in cooperation with mild vibration to eliminate voids; Step 4: Preparation of the heavy metal removal layer 6 and the Xuanyuangyu photocatalytic layer 7: First, mix strong acid cation and strong base anion exchange resins in a volume ratio of 1:1, activate them with 0.5M NaCl solution for 4 hours and rinse until the conductivity < 5 μS / cm; At the same time, immerse Xuanyuangyu ceramic balls with a pore size of 0.2-1 μm in 3wt% TiO 2 nano-slurry, dry it and sinter it at 800 °C for 2 hours to load the photocatalytic layer. Then, first fill a 20 mm ion exchange resin layer, then lay a 20 mm Xuanyuangyu photocatalytic ball layer, and install a polypropylene spacer between the two layers to avoid displacement. The entire Xuanyuangyu photocatalytic layer 7 is installed between the filter discs 72; Step 5: Encapsulation of the ultrafiltration precision layer 8: Prepare a ceramic composite ultrafiltration membrane disc with a pore size of 0.01 μm, seal the edge with food-grade epoxy resin or a hot melt gasket and install it in the special card slot in the middle section of the filter element, gently press and position it and make a circular anti-seepage seal. After installation, backwash it with pure water for 10 minutes, and confirm that the water flux ≥ 1.5 L / min at 0.2 MPa; Step 6: Preparation of the post-polishing layer 9: Fill the activated carbon powder that has passed through a 200-mesh sieve and has a specific surface area > 800 m² / g about 5 mm thick at the upper end of the spiral guide plate, and install a piece of PP cotton on the top layer to fix it; Step 7: Overall assembly: Install the mechanical pre-filter layer 3, activated carbon adsorption layer 5, heavy metal removal layer 6, Xuanyuangyu photocatalytic layer 7, ultrafiltration precision layer 8 and post-polishing layer 9 from top to bottom inside the filter element housing 1 in turn through the clamp 2 to complete the assembly. The systematic and modular preparation process improves production efficiency and quality consistency, and is convenient for batch manufacturing and later maintenance and replacement.

[0019] In this article, specific examples are used to elaborate on the principles and implementation modes of the present invention. The description of the above examples is only used to help understand the method and its core idea of the present invention. The above is only the preferred implementation mode of the present invention. It should be noted that due to the limited nature of written expression and objectively existing infinite specific structures, for those of ordinary skill in the art, without departing from the principles of the present invention, several improvements, refinements or changes can be made, or the above technical features can be combined in an appropriate manner; these improvements, refinements, changes or combinations, or directly applying the concept and technical solution of the invention to other occasions without improvement, shall all be regarded as the protection scope of the present invention.

Claims

1. A black jade drinking water purification filter element, comprising a clamp (2), characterized in that: The clamp (2) is mounted on the upper and lower ends of the filter element housing (1); the upper and lower ends of the outer side of the filter element housing (1) are both mounted with sealing rings (4); and the inner side of the filter element housing (1) is sequentially mounted with a mechanical pre-filtration layer (3), an activated carbon adsorption layer (5), a heavy metal removal layer (6), a black jade photocatalytic layer (7), an ultrafiltration precision layer (8), and a post-polishing layer (9) from top to bottom; The filter element housing (1) comprises a column housing (11), an annular groove (12) is provided on the outer sides of the upper and lower ends of the column housing (11), a mounting groove (14) is provided on the inner sides of the upper and lower ends of the column housing (11), and a spiral guide groove (13) is provided on the inner side of the upper end of the column housing (11); The mechanical pre-filter layer (3) comprises a positioning frame (31), the inner sides of the upper end and the lower end of the positioning frame (31) are provided with a plurality of through holes (32) distributed in an annular manner, and a stacked filter screen plate (33) is installed on the middle outer side of the positioning frame (31); The black jade photocatalytic layer (7) comprises a sealed shell (71), the inner sides of the upper and lower ends of the sealed shell (71) are fixedly connected with filter discs (72), black jade ceramic microspheres are placed between the filter discs (72), and the surface-loaded antibacterial photocatalyst TiO2 is evenly distributed inside the black jade ceramic microspheres.

2. The Xuanhuangyu drinking water purification filter element according to claim 1, characterized in that: The outer side of the column shell (11) is connected to the sealing ring (4) via an annular groove (12), and the annular groove (12) and the sealing ring (4) correspond one to one. The inner side of the column shell (11) is connected to the clamp (2) via an installation groove (14), and the installation groove (14) and the clamp (2) correspond one to one. The height of the spiral guide groove (13) is half the height of the mechanical pre-filter layer (3).

3. The Xuanhuangyu drinking water purification filter element according to claim 1, characterized in that: The clamp (2) comprises an open ring (21), both ends of the open ring (21) are provided with disassembly holes (22), and the inner wall of the disassembly hole (22) is provided with annularly distributed anti-slip grooves.

4. The Xuanhuangyu drinking water purification filter element according to claim 1, characterized in that: The lateral projection of the positioning frame (31) is H-shaped, and the lower half of the laminated filter screen plate (33) is in close contact with the inner wall of the column shell (11). The laminated filter screen plate (33) is porous PP cotton, and the pore size of the laminated filter screen plate (33) is 5-10 μm.

5. The Xuanhuangyu drinking water purification filter element according to claim 1, characterized in that: The activated carbon adsorption layer (5) is coconut shell activated carbon particles, and the particle size of the coconut shell activated carbon particles is 0.7-1.7 mm.

6. The Xuanhuangyu drinking water purification filter element according to claim 1, characterized in that: The heavy metal removal layer (6) is made of a cross-linked polymer ion exchange resin.

7. The Xuanhuangyu drinking water purification filter element according to claim 1, characterized in that: Micropores are provided inside the black jade ceramic microspheres, and the diameter of the micropores provided inside the black jade ceramic microspheres is 0.2-1 μm.

8. The Xuanhuangyu drinking water purification filter element according to claim 1, characterized in that: The ultrafiltration precision layer (8) is made of stacked ceramic composite ultrafiltration membranes, and the pore size of the ceramic composite ultrafiltration membrane is 0.01 μm.

9. The Xuanhuangyu drinking water purification filter element according to claim 1, characterized in that: The post-polishing layer (9) comprises a plastic shell (91) arranged in a cylindrical shape, a spiral guide plate (92) being installed inside the plastic shell (91), and food-grade aromatic activated carbon powder being evenly attached to the upper surface of the spiral guide plate (92).

10. A method for preparing a Xuanhuang jade drinking water purification filter element according to any one of claims 1 to 9, characterized in that: Step 1: Filter housing (1) and pretreatment: Food-grade polypropylene pipe is used to process the filter housing (1) of the required diameter, and positioning bosses are reserved on the inner wall to fix the filter media at each level. All plastic parts are first ultrasonically cleaned to remove oil and impurities, and then dried in a 60°C oven for 2 hours; Step 2: Filling of the mechanical pre-filtration layer (3): Cut the screened and dust-free porous PP cotton into sheets that match the inner diameter of the filter element, and fill them into the outside of the positioning frame (31) in two layers in the order of "bottom first and top later". The filling height is controlled at 15-20mm, and lightly pressed with a special pressing rod to make the cotton layer flat and tight without obvious gaps; Step 3: Construction of activated carbon adsorption layer (5): Wash coconut shell activated carbon particles with a particle size of 0.7-1.7 mm with deionized water until clear, dry at 120°C for 4 hours, take the dried particles and fill them by volume to a height of about 25 mm in the middle of the filter element, add them in batches and gently vibrate to eliminate gaps; Step 4: Preparation of heavy metal removal layer (6) and Xuanhuangyu photocatalytic layer (7): First, a strong acid cation exchange resin and a strong base anion exchange resin were mixed in a volume ratio of 1:1, activated with 0.5M NaCl solution for 4 hours and rinsed until the conductivity was less than 5 µS / cm; At the same time, the black jade ceramic balls with a pore size of 0.2-1 μm are impregnated with 3wt% TiO2 nano-slurry, dried and sintered at 800°C for 2 hours to load the photocatalytic layer, and then a 20 mm ion exchange resin layer is filled first, and then a 20 mm black jade photocatalytic ball layer is laid, and a polypropylene spacer is added between the two layers to prevent displacement. The black jade photocatalytic layer (7) is installed as a whole between the filter discs (72); Step 5: Ultrafiltration precision layer (8) packaging: Prepare a ceramic composite ultrafiltration membrane disc with a pore size of 0.01µm, seal the edges with food-grade epoxy resin or hot-melt gasket, and install it in the special slot in the middle of the filter element. Press lightly to position and make a ring-shaped anti-seepage package. After installation, backwash with pure water for 10 minutes to confirm that the water flux is ≥1.5 L / min at 0.2 MPa; Step 6: Preparation of post-polishing layer (9): Fill the activated carbon powder with a surface area of ​​>800 m² / g through a 200 mesh sieve on the upper end of the spiral guide plate to a thickness of about 5 mm, and then fix a piece of PP cotton on the top layer; Step 7: Overall assembly: The mechanical pre-filtration layer (3), the activated carbon adsorption layer (5), the heavy metal removal layer (6), the black jade photocatalytic layer (7), the ultrafiltration precision layer (8) and the post-polishing layer (9) are sequentially installed from top to bottom inside the filter element housing (1) through the clamp (2) to complete the assembly.

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