Honeycomb biological carrier and manufacturing method thereof

Abstract

The invention discloses a honeycomb biological carrier and a manufacturing method thereof, and relates to the technical field of sewage treatment. Comprising a supporting frame, at least one layer of honeycomb structure, a spiral outer rib and a coating, wherein a treatment space is formed in the supporting frame in a surrounding manner; the honeycomb structure is connected with the supporting frame and is arranged in the treatment space; the spiral outer rib is arranged between the honeycomb structure and the supporting frame, and the surface of the supporting frame, the surface of the honeycomb structure and the surface of the spiral outer rib are coated with the coating; the spiral outer ribs are used for increasing spiral disturbance of water flow, by arranging the spiral outer ribs, original linear or disordered motion of the water flow can be forcibly converted into rotary motion guided by the outer contours of the spiral outer ribs, and a retained water film on the surface of a carrier can be effectively damaged; and the substance exchange between the sewage and the surface of the biological membrane is changed from diffusion to convection, so that sludge and impurities are prevented from being deposited in pore channels.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a cellular biological carrier and its manufacturing method. Background Technology

[0002] Moving bed biofilm reactor (MBBR) technology is considered a major advancement in wastewater treatment. Its core concept combines the stability and efficiency of biofilm processes with the flexibility of activated sludge processes. Early biofilm methods (such as biofilters and rotating biological contactors) suffered from problems such as clogging, the need for backwashing, and large footprints. MBBR introduces suspended, freely moving plastic packing material as a biofilm carrier, which circulates within the reactor under aeration or stirring to treat wastewater.

[0003] In existing technologies, in pursuit of high specific surface area, internal flow channels are often complex and narrow (such as honeycomb or cross-ribbed structures). When treating wastewater containing fibers or viscous substances at low flow rates, biofilms and impurities easily accumulate in dead corners, forming a "core blockage" phenomenon. This leads to packing accumulation, uneven fluidization, and even the formation of dead zones within the reactor, resulting in a sharp drop in overall treatment efficiency.

[0004] Therefore, it is necessary to develop and design cellular biological carriers and their manufacturing methods. Actively enhancing water flow disturbance, achieving self-cleaning, and maintaining high biological activity and mass transfer efficiency over a long period of time are technical problems that urgently need to be solved by those skilled in the art. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a cellular biological carrier and its manufacturing method, which actively enhances water flow disturbance, achieves self-cleaning, and maintains high biological activity and mass transfer efficiency over a long period.

[0006] To achieve the above objectives, the present invention provides the following solution: A cellular biocarrier includes a support frame surrounding a processing space, at least one layer of cellular structure connected to the support frame and disposed inside the processing space, a spiral outer rib disposed between the cellular structure and the support frame, and a coating applied to the surfaces of the support frame, the cellular structure and the spiral outer rib, wherein the spiral outer rib is used to increase the spiral disturbance of the water flow.

[0007] Preferably, the support frame includes at least two annular smooth strips spaced apart, and support disks are provided at both ends perpendicular to the circular surface formed by the smooth strips. The support disks are connected to the smooth strips and adjacent smooth strips through the spiral outer ribs.

[0008] Preferably, the support plate is provided with a through hole for sewage to pass through.

[0009] Preferably, at least two spiral outer ribs are provided, and they are evenly distributed in the circumferential direction of the support plate and the smooth belt.

[0010] Preferably, the honeycomb structure has at least two layers, and adjacent honeycomb structures are spaced apart and connected by support ribs.

[0011] Preferably, the honeycomb structure is composed of at least seven vertically connected hexagonal honeycomb cells, and the support ribs are spaced apart on adjacent honeycomb surfaces of the hexagonal honeycomb cells.

[0012] Preferably, the helical angle of the helical outer rib is 15 to 30 degrees.

[0013] This invention also discloses a method for manufacturing a cellular biological carrier, which mainly includes the following steps: Preparation of injection molding solution; The injection molding solution is poured into a mold corresponding to the cellular biocarrier; The coating is applied to the surface of the injection-molded cellular biocarrier.

[0014] Preferably, the injection molding solution comprises 95%-98% high-density polyethylene particles and 2%-5% nano-titanium dioxide.

[0015] Preferably, the coating is prepared from the following components in parts by weight, based on the weight of tetraethoxysilane, with the following weight ratio between the components: 9.33 parts tetraethoxysilane, 0.946 parts 3-aminopropyltriethoxysilane, 5 parts silica nanoparticles, 5 parts titanium dioxide nanoparticles, 2 parts zinc oxide nanoparticles, and 0.3 parts Ag-TiO2 composite nanoparticles.

[0016] The present invention achieves the following technical effects compared to the prior art: By setting helical outer ribs, when water flows into the honeycomb biocarrier, the original straight or disordered motion of the water flow can be forcibly transformed into a rotational motion guided by the outer contour of the helical outer ribs, and a composite helical flow in the axial and circumferential directions can be induced. This strong rotation and helical upward / downward water flow can effectively destroy the stagnant water film on the surface of the carrier, so that the material exchange between sewage and the surface of the biofilm changes from diffusion to convection, significantly improving the mass transfer rate of oxygen, pollutants and nutrients. Even when the overall flow velocity is low, the rotation of the carrier itself can maintain a high local mass transfer efficiency. Moreover, the rotational motion of the water flow makes it difficult for fibers and suspended solids to wrap and fix on the outer surface of the honeycomb biocarrier, preventing sludge and impurities from depositing in the channels. Plasma activation pretreatment of the honeycomb biocarrier by setting a coating can improve the surface adhesion of the honeycomb biocarrier and improve the sewage treatment effect. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Appendix Figure 1 This is a schematic diagram of the isometric structure of the cellular biological carrier disclosed in this invention; Appendix Figure 2 This is a top view structural diagram of the cellular biological carrier disclosed in this invention; Appendix Figure 3 This is a schematic diagram of the longitudinal cross-sectional structure of the cellular biological carrier disclosed in this invention; Appendix Figure 4 This is a schematic diagram of the cross-sectional structure of the cellular biological carrier disclosed in this invention; 1. Through hole; 2. Support plate; 3. Honeycomb structure; 4. Smooth band; 5. Spiral outer rib; 6. Support side rib; 7. Hexagonal honeycomb; 8. Support rib. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] The purpose of this invention is to provide a cellular biological carrier and its manufacturing method, which actively enhances water flow disturbance, achieves self-cleaning, and maintains high biological activity and mass transfer efficiency over a long period of time.

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] refer to Figures 1-4The honeycomb biocarrier disclosed in this embodiment of the invention includes at least a support frame, which encloses a wastewater treatment space. At least one layer of honeycomb structure 3 is disposed inside the wastewater treatment space. The honeycomb structure 3 is connected to the inner wall of the support frame. A spiral outer rib 5 is disposed between the honeycomb structure 3 and the support frame. The surfaces of the spiral outer rib 5, the honeycomb structure 3, and the support frame are all coated with a coating. The spiral outer rib 5 is used to increase the spiral disturbance of the water flow. By setting the spiral outer rib 5, when the water flow enters the honeycomb biocarrier, the original linear or disordered motion of the water flow can be forcibly transformed into a rotational motion guided by the outer contour of the spiral outer rib 5, and axial and... The circumferential composite spiral flow, with its intense rotation and spiraling upward / downward flow, effectively disrupts the stagnant water film on the carrier surface. This transforms the material exchange between wastewater and the biofilm surface from primarily diffusion to primarily convection, significantly increasing the mass transfer rate of oxygen, pollutants, and nutrients. Even at low overall flow rates, the carrier's own rotation maintains high local mass transfer efficiency. Furthermore, the rotational motion of the water flow makes it difficult for fibers and suspended solids to become entangled and fixed on the outer surface of the honeycomb biocarrier, preventing sludge and impurities from depositing within the pores. Plasma activation pretreatment of the honeycomb biocarrier with a coating enhances its surface adhesion and improves wastewater treatment efficiency.

[0023] refer to Figures 1-4 In one embodiment, the support frame includes at least two spaced-apart annular smooth strips 4, with support disks 2 at both ends of the smooth strips 4. The support disks 2 are connected to the smooth strips 4 and adjacent smooth strips 4 by spiral outer ribs 5. The support disks 2, smooth strips 4, and spiral outer ribs 5 together form the outer frame of a spherical honeycomb biocarrier. Among all geometries, the sphere has the smallest specific surface area to volume ratio, which means that it has the least shape resistance when moving in the fluid. This allows the carrier to be easily started and kept in a suspended and flowing state at lower hydraulic or aeration intensities, further reducing fluidization energy consumption. Moreover, with the spiral outer ribs 5, it is easier to achieve carrier rotation and improve water flow disturbance. The annular smooth strips 4 are parallel to the main direction of the fluid. The belt 4 provides a smooth contact surface, effectively reducing the frictional resistance of the carrier during the flow process, making its movement smoother. More energy is used to drive rotation rather than overcome friction. The support plate 2, the smooth belt 4, and the spiral outer rib 5 are interconnected to form a stable spatial truss structure based on triangles and rings. This structure can evenly distribute the force to the entire frame, giving the carrier extremely high mechanical strength. It can withstand long-term water flow impact, collisions between carriers, and physical stress during the cleaning process, greatly extending its service life. The external frame composed of the support plate 2, the smooth belt 4, and the spiral outer rib 5 is a hollow structure with large pores, which hardly obstructs the water flow, ensuring that sewage can flow into the interior of the carrier without hindrance and fully contact the honeycomb structure 3.

[0024] It should be noted that the diameter of the sphere is 2.2 mm, the width of the smooth strip 4 is 2.5 mm, and the thickness is 1.8 mm.

[0025] refer to Figures 1-4 In one embodiment, the support plate 2 is provided with through holes 1 for sewage to pass through. Preferably, there are eight through holes 1, one in the center and seven evenly distributed around the perimeter. By providing through holes 1, sewage can not only enter from the side through the gaps between the smooth strips 4, but also directly pass through the support plate 2 from both ends, flowing into the interior through multiple paths. This achieves three-dimensional and penetrating hydraulic exchange of the internal space of the carrier, ensuring that each honeycomb channel can obtain fresh sewage and dissolved oxygen, completely eliminating the internal hydraulic dead zone, and making the biofilm of the entire carrier work in a highly efficient state.

[0026] The diameter of the through hole 1 is 2.8 mm, and the center distance between adjacent through holes 1 is 7.3 mm. The smooth strip 4 is set as two strips with a roughness of Ra0.3μm-0.8μm, and they are arranged symmetrically.

[0027] refer to Figures 1-4 In one implementation, at least two spiral outer ribs 5 are provided and evenly distributed around the support plate 2 and the smooth belt 4. The at least two spiral outer ribs 5, evenly and symmetrically arranged, can generate a balanced rotational torque, ensuring that when impacted by water flow, they can rotate smoothly and continuously around their geometric center, avoiding unstable swaying and making the motion trajectory more controllable. Multiple spiral ribs are equivalent to multiple small guide plates working simultaneously. They work together on the water flowing through the carrier, which can draw a larger range of water into the spiral motion, significantly enhancing the intensity and range of inducing the surrounding water to form spiral turbulence. The even distribution ensures that water flowing into the vicinity of the carrier from any direction can be effectively captured and converted into rotational power and eddies by at least one spiral outer rib 5, eliminating dead angles in fluid contact and improving the effect of sewage treatment.

[0028] It should be noted that there are 8 spiral outer ribs 5, with a height of 18mm, a rib width of 0.9mm, and a rib thickness of 0.8mm.

[0029] As one implementation method, the honeycomb structure 3 has at least two layers. Adjacent honeycomb structures 3 are spaced apart and connected by support ribs 8. The interlayer spacing of the honeycomb structure 3 forces the water flow to enter a relatively open mixing chamber (interval zone) after flowing through one layer of honeycomb. Turbulent mixing and material redistribution occur here, and the water then enters the next layer of honeycomb evenly. This significantly improves the uniformity and thoroughness of the contact between sewage and biofilm, greatly enhances the mass transfer efficiency and the overall removal rate of pollutants. Moreover, the interlayer spacing of the honeycomb structure 3 allows sewage to pass through the side of the honeycomb biological carrier, further increasing the contact area between sewage and the honeycomb biological carrier and improving the sewage treatment effect.

[0030] refer to Figures 1-4 As a preferred approach, the honeycomb structure 3 is composed of at least seven interconnected hexagonal honeycomb cells 7, with support ribs 8 spaced apart on adjacent honeycomb surfaces of the hexagonal honeycomb cells 7. Among all planar mosaic patterns, the regular hexagon can enclose the largest area with the smallest total perimeter. Within the same projected area, the hexagonal honeycomb structure 3 can provide the largest effective attachment wall surface (specific surface area) while using the least amount of material, achieving a balance between lightweight and high performance. The hexagonal structure has extremely high in-plane stiffness and compressive strength, effectively resisting deformation caused by water flow impact. Each hexagonal honeycomb cell 7 is a vertical, continuous microchannel, which ensures that water can flow smoothly in the vertical direction, reducing vertical resistance. The honeycomb cells are connected by a common wall, and the wall may have micropores or allow material diffusion, realizing horizontal material exchange and creating a three-dimensional interconnected, regular, and orderly channel network. This ensures the long and tortuous path required for sufficient contact between sewage and biofilm, while avoiding dead zones and blockages caused by chaotic channels. By combining the open gaps between layers, an ideal flow pattern of "vertical main channel + horizontal diffusion + interlayer mixing" is formed. The support rib 8 is connected to the vertical sidewall of the hexagon, rather than the corner of the honeycomb, because the sidewall is the stress surface. This connection can distribute the interlayer load more evenly to the entire honeycomb wall panel and avoid stress concentration at the corner. The support rib 8 is attached to the outer surface of the sidewall or embedded in the wall thickness, which has almost no obstruction to the smoothness of the internal flow channel of the hexagon, ensuring the integrity of the flow channel. The support rib 8 itself also provides an additional biofilm attachment surface area, and its streamlined design can guide the interlayer water flow.

[0031] It should be noted that the support ribs 8 are also coated with a coating. The interior of the honeycomb structure 3 is connected by the support ribs 8, and the circumferential direction of the honeycomb structure 3 is connected to the smooth belt 4 by the support side ribs 6 to ensure the stability of the honeycomb structure 3.

[0032] It should be noted that the honeycomb structure 3 preferably has 6-7 layers of hexagonal honeycomb mesh (the side length of the hexagonal honeycomb body 7 is 3.0 mm, the wall thickness is 1.8 mm, and the porosity is >80%), the coating thickness is 0.5 μm-3 μm, and the support ribs 8 (thickness 0.5 mm, height 0.2 mm) are set every 3 mm-4 mm. The hexagonal honeycomb bodies 7 in adjacent honeycomb structures 3 are staggered, which can further increase the contact area between sewage and honeycomb structure 3 and improve sewage treatment efficiency.

[0033] Micro-gaps (less than 0.1 mm) are reserved between adjacent hexagonal honeycomb cells 7 and between adjacent honeycomb structures 3. These gaps ensure the connectivity of the internal space of the honeycomb structure 3 in the height and radial directions, forming a three-dimensional water flow network.

[0034] refer to Figures 1-4 As one implementation method, the spiral angle of the spiral outer rib 5 is 15 degrees to 30 degrees. Within this range, the spiral rib can generate a sufficiently strong rotational torque and a moderate axial thrust at the same time, ensuring that the carrier can rotate at high speed and stably, and can also effectively participate in the overall circulation flow in the reactor to achieve uniform fluidization throughout the tank.

[0035] In this embodiment, the honeycomb structure 3 provides 900m 2 / m 3 -1400m 2 / m 3 Specific surface area supports microbial attachment; spiral outer ribs 5 generate self-spinning flow, inhibit sludge aggregation, and increase oxygen transfer rate by 10%–15%; through holes 1 ensure water flow continuity and enhance anti-clogging performance; smooth band 4 reduces membrane expansion (≤8%) and optimizes biofilm uniformity; coating reduces contact angle (≤25°) and accelerates biofilm formation (3–5 days).

[0036] This invention also discloses a method for manufacturing a cellular biological carrier, which mainly includes the following steps: S1. Preparation and Injection Molding of Composite Masterbatch: a. Preparation of modified injection molding solution: High-density polyethylene granules with a melt index of 5g / 10min-20g / 10min are dried at 80°C-90°C until the moisture content is <0.02%. Then, they are mixed evenly with nano-titanium dioxide reinforcing agent accounting for 2%-5% of the weight of high-density polyethylene to obtain modified injection molding solution (temperature 215°C). This can remove moisture from the raw materials to prevent injection molding porosity defects, and nano-TiO2 enhances the resistance to ultraviolet (UV) radiation and wear resistance.

[0037] b. Injection molding: The modified injection solution is injected into the pre-designed mold cavity, the shape of which corresponds to the target macroscopic structure and internal three-dimensional mesh flow channel of the honeycomb biological carrier; after melting, plasticizing, holding pressure and cooling, the polymer carrier matrix with honeycomb internal flow channel is obtained by demolding, which can form complex geometric structures, ensure the accuracy of honeycomb mesh and external ribs, and optimize fluid dynamics performance.

[0038] The injection is carried out through a hot runner system into a 24-cavity H13 steel mold at an injection pressure of 80MPa-120MPa. The pressure is held for 5-10 seconds to fill the honeycomb structure 3. After cooling for 20-40 seconds, the material is demolded through 8-12 ejector pins to form a biological carrier with an outer diameter of 22.0mm and a height of 18.0mm. The carrier includes 8 20° spiral outer ribs 5 (0.9mm high and 0.8mm thick), 8 2.8mm through holes 1, and an internal hexagonal honeycomb grid (3.0mm side length and 1.8mm wall thickness).

[0039] S2. Surface pretreatment of carrier substrate: The surface of the polymer carrier matrix obtained in step S1 is subjected to plasma activation treatment to improve its surface energy; S3. Functional Coating Preparation and Application: a. Preparation of sol-gel coating solution: Based on tetraethyl orthosilicate, mix 9.33 parts by weight of tetraethoxysilane, 0.946 parts by weight of 3-aminopropyltriethoxysilane, 5 parts by weight of silica nanoparticles, 5 parts by weight of titanium dioxide nanoparticles, 2 parts by weight of zinc oxide nanoparticles and 0.3 parts by weight of silver-doped titanium dioxide nanoparticles (Ag-TiO2) to prepare a sol-gel coating solution; b. Coating and curing: Using a spraying method, the sol-gel coating solution is coated onto the surface of the polymer carrier substrate treated in step S2 under a pressure of 0.2 bar-0.5 bar to form 1-3 layers of coating, each wet film with a thickness of 0.5 μm-1 μm; then cured at 90°C for 1.5-2 hours to form a multifunctional composite coating on the surface of the polymer carrier substrate, thus producing a multifunctional cellular biological carrier.

[0040] It can form a hydrophilic coating (contact angle ≤25°), accelerate microbial biofilm formation, and enhance the coating's resistance to peeling.

[0041] It should be noted that in silver-doped titanium dioxide nanoparticles, the amount of silver doping is 0.5%-3.0% of the weight of titanium dioxide.

[0042] Cellular biological carriers can also be prepared using 3D printing technology, specifically by using selective laser sintering (SLS) technology to form cellular structures with an accuracy of ±0.01 mm.

[0043] It can achieve complex geometries and porosity of over 85%.

[0044] Alternatively, the honeycomb mesh can be replaced with round holes of 3mm in diameter, which reduces manufacturing complexity, simplifies demolding, and reduces mold costs by about 20%.

[0045] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A cellular biological carrier, characterized in that, It includes a support frame that surrounds a processing space, at least one layer of honeycomb structure (3) connected to the support frame and disposed inside the processing space, a spiral outer rib (5) disposed between the honeycomb structure (3) and the support frame, and a coating applied to the surfaces of the support frame, the honeycomb structure (3) and the spiral outer rib (5), wherein the spiral outer rib (5) is used to increase the spiral disturbance of the water flow.

2. The cellular biological carrier according to claim 1, characterized in that, The support frame includes at least two annular smooth strips (4) spaced apart, and support disks (2) are provided at both ends of the circular surface formed by the smooth strips (4). The support disks (2) are connected to the smooth strips (4) and adjacent smooth strips (4) by the spiral outer ribs (5).

3. The cellular biological carrier according to claim 2, characterized in that, The support plate (2) is provided with a through hole (1) for sewage to pass through.

4. The cellular biological carrier according to claim 2, characterized in that, The spiral outer ribs (5) are at least two in number and are evenly distributed in the circumferential direction of the support plate (2) and the smooth belt (4).

5. The cellular biological carrier according to claim 4, characterized in that, The honeycomb structure (3) has at least two layers, and adjacent honeycomb structures (3) are spaced apart and connected by support ribs (8).

6. The cellular biological carrier according to claim 5, characterized in that, The honeycomb structure (3) is composed of at least seven vertically connected hexagonal honeycomb bodies (7), and the support ribs (8) are spaced apart on the adjacent honeycomb surfaces of the hexagonal honeycomb bodies (7).

7. The cellular biological carrier according to claim 1, characterized in that, The spiral angle of the spiral outer rib (5) is 15 to 30 degrees.

8. A method for manufacturing a cellular biological carrier, characterized in that, The main steps include: Preparation of injection molding solution; The injection molding solution is poured into a mold corresponding to the cellular biocarrier; The coating is applied to the surface of the injection-molded cellular biocarrier.

9. The method for manufacturing a cellular biological carrier according to claim 8, characterized in that, The injection molding solution comprises 95%-98% high-density polyethylene particles and 2%-5% nano titanium dioxide.

10. The method for manufacturing a cellular biological carrier according to claim 8, characterized in that, The coating is formulated from the following components in parts by weight, based on the weight of tetraethoxysilane. The weight ratio of each component is as follows: 9.33 parts tetraethoxysilane, 0.946 parts 3-aminopropyltriethoxysilane, 5 parts silica nanoparticles, 5 parts titanium dioxide nanoparticles, 2 parts zinc oxide nanoparticles, and 0.3 parts Ag-TiO2 composite nanoparticles.

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