Suspended filler that realizes rapid fluidization and stable biofilm formation

Abstract

The present disclosure relates to the field of sewage (wastewater) treatment technology application, and particularly relates to a suspended filler that realizes rapid fluidization and stable biofilm formation. The suspended filler structurally comprises wave-surface-shaped frameworks, and every two adjacent rows of the wave-surface-shaped frameworks are mirror images of each other and are arranged in a staggered manner. The growth thickness of a biofilm of the suspended filler of the present disclosure is controlled within an effective range, such that the activity of the biofilm is maintained. As seen from the continuous ammonia nitrogen removal result, the removal rate of ammonia nitrogen is stabilized at 95% or above after hydraulic load fluctuation at different stages, thereby ensuring the operation stability of a biochemical system.

Description

A suspended filler with rapid fluidization and stable biofilm formation

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] The present disclosure claims priority to application number 2024100500754 filed with the Patent Office of China on January 11, 2024, entitled “A Suspended Filler with Rapid Fluidization and Stable Film Formation,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the technical field of wastewater treatment technology, and in particular to a suspended filler with rapid fluidization and stable biofilm formation. Background Art

[0004] Globally, sewage (wastewater) is primarily treated and recycled through a combined physicochemical and biochemical approach. Nearly 100 processes and reactors have been developed for the biochemical treatment process, aiming to enhance the ability of microorganisms to remove pollutants from liquids. Biological wastewater treatment can be divided into two main categories based on the presence of microorganisms within the biochemical system: activated sludge and biofilm. In the activated sludge process, microorganisms are maintained in a completely mixed and suspended state within the sewage. Industry practices primarily utilize nitrification solution and sludge recirculation to maintain microbial concentration within the biochemical system, effectively removing pollutants. In the biofilm process, microorganisms adhere to and grow on the surface of filter media or fillers, forming a biofilm. Compared to the activated sludge process, the biofilm process is characterized by achieving a long residence time between microorganisms and water. By effectively trapping the carrier filler, microorganisms within the reactor are effectively enriched and retained, significantly enhancing the biochemical system's ability to remove pollutants. Advantages of the biofilm process include strong shock resistance, high biological treatment efficiency, a small footprint, low sludge production, and easy operation and management.

[0005] There are two types of biofilm methods: fluidized bed and fixed bed. Fixed bed biofilm processes often have the risk of membrane bed clogging and dead zone formation, and the pollutants in the sewage are always not in sufficient contact with the biofilm on the fixed bed. The fluidized bed biofilm process eliminates the above risks, and the fluidized bed biofilm process represented by the moving bed biofilm reactor (MBBR) is the most widely used. MBBR technology uses suspended fillers with a density close to that of the sewage to be treated as a carrier for microbial attachment and growth, and achieves fluidization of the suspended fillers and sufficient contact with the sewage to be treated through aeration or plug flow. The biofilm enriched and grown on the surface of the suspended fillers adsorbs and degrades pollutants in the sewage, and the sewage is efficiently purified.

[0006] MBBR suspended fillers are classified into two main categories: flexible (foamed) and rigid (injection molded or extruded). The biofilm formation performance of suspended fillers is currently evaluated by the protected area available for microbial growth. The protected area refers to the area of ​​the filler that is protected from external impact and shear.

[0007] Flexible suspended fillers, such as blocky sponges (JP2009066592A and US20050244944A1), offer a vast protected area for microbial growth. This is because the sponge structure allows a large number of microorganisms to accumulate within it, significantly increasing the biomass of the biochemical system during initial use. However, the microorganisms accumulated within the sponge create a dead zone within the filler, preventing biofilm renewal. Furthermore, the flexible sponge structure suffers from severe wear and tear due to long-term collision and shear in the system, leading to a rapid decline in the performance and functionality of this type of filler over time.

[0008] Rigid suspended fillers, characterized by a tubular or cylindrical shape (“Fernando Morgan-Sagastume (2018) Biofilm development, activity and the modification of carrier material surface properties in moving-bed biofilm reactors (MBBRs) for wastewater treatment, Critical Reviews in Environmental Science and Technology, 48:5, 439-470” page 443, US6126829A, US7189323B2, and AU2021334171A1), have a relatively stable structure, a long service life, and improve the efficiency of biochemical systems. They are currently the most widely used suspended fillers in the industry. The drawback of rigid fillers is that the protected area is relatively small, and with fluctuations in influent water quality, the protected area of ​​the filler often becomes clogged. This clogging problem is similar to the dead zone problem of flexible fillers, meaning that effective biofilm renewal cannot be achieved. Another common problem with rigid fillers is that it takes too long for them to fluidize with the sewage during the initial addition phase, generally taking 7-15 days or even longer. This greatly reduces the filler's biofilm formation speed and increases the reactor startup time.

[0009] A common problem in all known MBBR (Medium-Band Braking Reinforced Biofilm) applications is the uncontrolled growth of biofilm within the designed protected zone of the packing. This results in the actual performance of the suspended packing being consistently below, or far below, the designed performance. Due to frequent fluctuations in influent wastewater quality, excessive biofilm growth in the protected zone of the packing often occurs due to fluctuations in hydraulic shock loads. This causes packing clogging and the formation of dead zones, significantly reducing the packing's oxygen and / or mass transfer efficiency and compromising the operational stability of the biochemical system.

[0010] In view of this, the present disclosure is proposed. Summary of the Invention

[0011] According to the background technology, the growth control and dynamic renewal of biofilm are crucial to the stable functioning of suspended fillers. The present disclosure aims to address the problems of existing MBBR suspended fillers, such as long fluidization time in the initial stage (i.e., startup stage), high tumbling energy consumption, and uncontrolled biofilm growth, which lead to poor operational stability of the biochemical system. The present disclosure provides a suspended filler that can quickly fluidize and control biofilm growth.

[0012] In order to achieve the above objectives, the technical solutions disclosed in this disclosure are as follows:

[0013] The present disclosure provides a suspension filler, wherein the suspension filler structure comprises a wave-shaped skeleton, and two adjacent rows of the wave-shaped skeletons are mirror images of each other and are arranged in a staggered manner.

[0014] Preferably, two adjacent rows of skeletons are connected via contact points of adjacent wave-shaped skeletons, and the concave areas of the wave surfaces serve as biofilm growth areas.

[0015] Preferably, the structure of the suspended filler further comprises partition ribs, two adjacent rows of wave-shaped skeletons are connected by the partition ribs, and the cavity enclosed by the depression of the wave surface and the partition ribs serves as the biofilm growth area.

[0016] Preferably, the wavy skeleton structure of the suspended filler includes one or more combinations of pure sine wave, sine wave, square wave, triangle wave, half wave, trapezoidal wave and honeycomb wave.

[0017] Preferably, the thickness of the suspended filler is 0.1-7.0 mm, more preferably 0.15-3.5 mm.

[0018] Preferably, the thickness of the partition rib is ≤1.0 mm, more preferably ≤0.4 mm.

[0019] Preferably, the wave surface thickness of the wave-shaped skeleton is 0.05-2.0 mm, more preferably 0.1-0.5 mm.

[0020] Preferably, the wave surface width of the wave-shaped skeleton is 0.05-50 mm, more preferably 0.2-30 mm, and most preferably 0.5-2.0 mm.

[0021] Preferably, the maximum depth of the recessed area is 0.05-5.0 mm, more preferably 0.1-1.5 mm, and most preferably 0.5-1.0 mm. The effective and stable function of the biofilm depends on the effective dynamic replacement and growth thickness control of the biofilm. The maximum depth of the chamber or recessed area can determine the maximum thickness of the biofilm.

[0022] Preferably, the ratio of the maximum depth to the maximum opening width of the recessed area is 5:1-1:10, so that the suspended filler can achieve a filler fluidization of not less than 50% of the reactor filling rate within 24 hours, further preferably 3:1-1:5, and most preferably 2:1-1:2, so that the suspended filler can achieve a filler fluidization of not less than 50% of the reactor filling rate within 4 hours.

[0023] Preferably, the shape of the suspended filler is saddle-shaped, C-shaped, S-shaped, hexagonal, circular, rectangular or a non-planar shape with a cutout, and further preferably circular, hexagonal, saddle-shaped, S-shaped or a non-planar shape with a cutout, so as to reduce the energy consumption of aeration fluidization and prevent fluidization wall adhesion and stacking between fillers.

[0024] The beneficial effects of the present disclosure are:

[0025] In response to the problems of known MBBR suspended fillers such as long fluidization time in the initial stage (i.e., the startup stage), high energy consumption for operation and tumbling, and uncontrollable biofilm growth, the present disclosure has developed a suspended filler with rapid fluidization, low energy consumption and stable biofilm formation. The suspended filler can complete the fluidization of fillers with a pool filling rate of more than 50% within 24 hours (traditional MBBR suspended fillers require about 7-15 days or even longer). When responding to different hydraulic load fluctuations, the biofilm growth thickness of the suspended filler disclosed in the present disclosure is controlled within an effective range, and the biofilm activity is maintained. From the results of continuous ammonia nitrogen removal, after hydraulic load fluctuations at different stages, the ammonia nitrogen removal rate is stable at more than 95% (traditional fillers often become clogged, resulting in a significant reduction in nitrification load), which ensures the stability of the biochemical system operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0027] FIG1 is a schematic diagram of a hexagonal suspension packing according to Example 1 of the present disclosure;

[0028] FIG2 is a schematic diagram of a wavy skeleton disclosed herein;

[0029] FIG3 is a schematic structural diagram of the connection between adjacent corrugated skeletons and partition ribs according to Example 1 of the present disclosure;

[0030] FIG4 is a schematic diagram of a structure in which adjacent wave-shaped skeletons are connected through connection points in Example 2 of the present disclosure;

[0031] FIG5 is a schematic diagram of a non-planar hexagonal suspension filler with cutouts according to Example 3 of the present disclosure;

[0032] FIG6 is a schematic diagram of a saddle-shaped suspended filler according to Example 4 of the present disclosure;

[0033] Figure 7 is a schematic diagram of different wave-shaped skeleton structures, a is a square wave, b is a triangle wave, c is a combination of half wave and trapezoidal wave, d is a trapezoidal wave;

[0034] FIG8 is a schematic diagram of a wavy skeleton structure of a honeycomb wave structure;

[0035] In the figure: 1. Thickness of the corrugated surface of the skeleton, 2. Concave area, 3. Maximum depth of the concave, 4. Partition ribs, 5. Width of the corrugated surface of the skeleton, 6. Maximum opening width of the concave, 7. Contact point of adjacent skeletons, 8. Thickness of the suspended filler. DETAILED DESCRIPTION

[0036] The embodiments of the present disclosure will be described in detail below with reference to the examples. However, those skilled in the art will appreciate that the following examples are intended only to illustrate the present disclosure and should not be construed as limiting the scope of the present disclosure. Where specific conditions are not specified in the examples, the experiments were performed under conventional conditions or the conditions recommended by the manufacturer. Where the manufacturer of the reagents or instruments is not specified, all are commercially available conventional products.

[0037] The endpoints of the ranges and any values ​​disclosed in this disclosure are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be considered to be specifically disclosed herein.

[0038] Example 1

[0039] Embodiment 1 of the present disclosure is shown in Figures 1, 2 and 3, where Figure 1 is a schematic diagram of a hexagonal suspended filler.

[0040] In FIG1 , the partition ribs 4 connect any two adjacent rows of mirror-image and staggered wave-shaped skeletons to form independent and repeated chambers, thereby constituting the overall structure of the suspended filler.

[0041] The staggered arrangement of any two adjacent rows of wave-shaped skeletons ensures the stability of the overall structure of the suspended filler. The partition ribs separate the internal channels of the wave-shaped skeleton to form independent chambers, which are used for temporary storage of liquid in the initial stage of filler use and for controlling biofilm growth in the later stage.

[0042] Both sides of the arbitrary wavy skeleton and partition ribs are surfaces for biofilm attachment and growth, and the chambers enclosed by the arbitrary recessed area 2 and the partition ribs 4 are areas for liquid temporary storage and biofilm growth control, which ensures that the filler has the largest space for biofilm growth and liquid temporary storage within a fixed spatial range.

[0043] The biofilm can only grow in the chamber. Once the maximum depth of the depression is exceeded (3), the biofilm exposed to the outside will be sheared and worn away by water or other fillers, thereby limiting the continued growth of the biofilm. This ensures that the biofilm can carry out effective oxygen and mass transfer processes.

[0044] Example 2

[0045] Embodiment 2 of the present disclosure is shown in FIG1 and FIG4 .

[0046] What is different from the implementation of Example 1 is that in this embodiment, any two adjacent rows of skeletons are connected through adjacent skeleton contact points 7 to form a stable whole, and a complete channel is formed inside along the direction of the skeleton wave surface width 5.

[0047] Both sides of any wave-shaped skeleton are surfaces for biofilm attachment and growth, and any recessed areas are interconnected inside the filler. These interconnected recessed areas 2 are areas for temporary storage of liquid and control of biofilm growth. This embodiment eliminates the spacing function of the partition ribs 4, and further increases the space provided for biofilm growth and temporary storage of liquid.

[0048] Example 3

[0049] Embodiment 3 of the present disclosure is shown in FIG5 , which is a schematic diagram of a non-planar hexagonal suspended filler with cutouts.

[0050] The main implementation of this embodiment is similar to that of embodiment 1. However, the difference from embodiment 1 is that one or more cutouts are added at any position of the hexagonal suspension filler, so that the overall outline of the suspension filler becomes a non-planar hexagon with cutouts.

[0051] In biochemical reactors, fluidization of non-planar hexagonal suspended packing with cutouts can effectively prevent the packing from adhering to the wall and stacking between packings.

[0052] Example 4

[0053] Embodiment 4 of the present disclosure is shown in FIG6 , which is a schematic diagram of a saddle-shaped suspended filler.

[0054] The main implementation of this embodiment is similar to that of embodiment 1. However, the difference from embodiment 1 is that the overall outline of the suspension filler is saddle-shaped.

[0055] Fluidizing saddle-shaped suspended fillers in biochemical reactors can reduce aeration or flow-pushing energy consumption and effectively prevent filler adhesion to the wall.

[0056] The suspended fillers described in the four examples above differ in their functional configurations, selected primarily to address different application scenarios and practical needs. What they share in common is that all examples contain areas for temporary liquid storage and biofilm growth control, and all achieve both biofilm growth control and rapid fluidization during the initial dosing phase. Based on the descriptions of the above examples, the following provides further explanations, validation of their effectiveness, and analysis of their results.

[0057] The suspended filler can be formed by continuous extrusion, injection molding or foaming of one or more organic high molecular polymer materials, inorganic materials, organic-inorganic composite materials and their modified materials.

[0058] The structure of the wave-shaped skeleton includes one or more combinations of pure sine wave, sine wave, square wave, triangle wave, half wave, trapezoidal wave and honeycomb wave.

[0059] The thickness of the suspended filler in Example 1 is preferably in the range of 0.5-6.5 mm. The overall thickness of the suspended filler in Example 1 is manufactured to be 0.8 mm, 2.0 mm, 4.0 mm and 6.0 mm for effect testing.

[0060] The thickness of the corrugated skeleton is preferably in the range of 0.1-2.5 mm. The corrugated thicknesses of the suspended filler skeletons with different overall thicknesses in Example 1 are respectively manufactured to be 0.1 mm, 0.5 mm, 1.0 mm and 2.0 mm for effect testing.

[0061] The thickness of the partition ribs is preferably in the range of 0-0.8 mm. The thicknesses of the partition ribs corresponding to the different overall thicknesses of the suspended fillers in Example 1 are respectively manufactured to be 0.05 mm, 0.3 mm, 0.5 mm and 0.6 mm for effect testing.

[0062] The wave surface width of the wave-shaped skeleton is preferably in the range of 0.5-2.0 mm. The wave surface width of the suspension filler skeleton with different overall thicknesses in Example 1 is manufactured to be 1.0 mm for effect testing.

[0063] The maximum depth of the depression is preferably in the range of 0.5-4.0 mm. The maximum depths of the depressions corresponding to the different overall thicknesses of the suspension fillers in Example 1 are respectively made into 0.5 mm, 1.5 mm, 3.0 mm and 4.0 mm for effect testing.

[0064] The ratio of the maximum depth of the depression to the maximum opening width of the depression is preferably in the range of 2:1-1:2. The ratio of the suspension fillers with different overall thicknesses in Example 1 is manufactured to be 1:1 for effect testing.

[0065] The thickness of the suspended filler in Example 2 is preferably in the range of 0.5-6.5 mm. The overall thickness of the suspended filler in Example 2 is manufactured to be 0.8 mm, 2.0 mm, 4.0 mm and 6.0 mm for effect testing.

[0066] The thickness of the corrugated skeleton is preferably in the range of 0.1-2.5 mm. The corrugated skeletons of the corrugated skeletons of different overall thicknesses of the suspended fillers in Example 2 are manufactured to have corrugated thicknesses of 0.10 mm, 0.5 mm, 1.0 mm and 2.0 mm for effect testing.

[0067] The partition ribs corresponding to the suspended fillers of different overall thicknesses in Example 2 were all manufactured to 0 mm for effect testing.

[0068] The wave surface width of the wave surface skeleton is preferably in the range of 0.5-2.0 mm. The wave surface width of the wave surface skeleton corresponding to the different overall thicknesses of the suspended fillers in Example 2 is manufactured to be 1.0 mm for effect testing.

[0069] The maximum depth of the depression is preferably in the range of 0.5-4.0 mm. The maximum depths of the depressions corresponding to the different overall thicknesses of the suspension fillers in Example 2 are respectively made into 0.5 mm, 1.5 mm, 3.0 mm and 4.0 mm for effect testing.

[0070] The ratio of the maximum depth of the depression to the maximum opening width of the depression is preferably in the range of 2:1-1:2. The ratio of the suspension fillers with different overall thicknesses in Example 2 is manufactured to be 1:1 for effect testing.

[0071] The thickness of the suspended filler in Example 3 is preferably in the range of 0.5-6.5 mm. The overall thickness of the suspended filler in Example 3 is manufactured to be 0.8 mm, 2.0 mm, 4.0 mm and 6.0 mm for effect testing.

[0072] The thickness of the corrugated skeleton is preferably in the range of 0.1-2.5 mm. The corrugated skeletons of the corrugated skeletons of different overall thicknesses of the suspended fillers in Example 3 are manufactured to have corrugated thicknesses of 0.10 mm, 0.5 mm, 1.0 mm and 2.0 mm for effect testing.

[0073] The thickness of the partition ribs is preferably in the range of 0-0.8 mm. The thicknesses of the partition ribs corresponding to the different overall thicknesses of the suspended fillers in Example 3 are respectively manufactured to be 0.05 mm, 0.3 mm, 0.5 mm and 0.6 mm for effect testing.

[0074] The wave surface width of the wavy skeleton is preferably in the range of 0.5-2.0 mm. The wave surface width of the wavy skeleton corresponding to the suspended fillers of different overall thicknesses in Example 3 is manufactured to be 1.0 mm for effect testing.

[0075] The maximum depth of the depression is preferably in the range of 0.5-4.0 mm. The maximum depths of the depressions corresponding to the different overall thicknesses of the suspension fillers in Example 3 are respectively made into 0.5 mm, 1.5 mm, 3.0 mm and 4.0 mm for effect testing.

[0076] The ratio of the maximum depth of the depression to the maximum opening width of the depression is preferably in the range of 2:1-1:2. The ratio of the suspension fillers with different overall thicknesses in Example 3 is manufactured to be 1:1 for effect testing.

[0077] The thickness of the suspended filler in Example 4 is preferably in the range of 0.5-6.5 mm. The overall thickness of the suspended filler in Example 4 is manufactured to be 0.8 mm, 2.0 mm, 4.0 mm and 6.0 mm for effect testing.

[0078] The thickness of the corrugated skeleton is preferably in the range of 0.1-2.5 mm. The corrugated skeletons of the corrugated skeletons of different overall thicknesses of the suspended fillers in Example 4 are manufactured to have corrugated thicknesses of 0.10 mm, 0.5 mm, 1.0 mm and 2.0 mm for effect testing.

[0079] The thickness of the partition ribs is preferably in the range of 0-0.8 mm. The thicknesses of the partition ribs corresponding to the different overall thicknesses of the suspended fillers in Example 4 are respectively manufactured to be 0.05 mm, 0.3 mm, 0.5 mm and 0.6 mm for effect testing.

[0080] The wave surface width of the wave-shaped skeleton is preferably in the range of 0.5-2.0 mm. The wave surface width of the wave-shaped skeleton corresponding to the suspended fillers of different overall thicknesses in Example 4 is manufactured to be 1.0 mm for effect testing.

[0081] The maximum depth of the depression is preferably in the range of 0.5-4.0 mm. The maximum depths of the depressions corresponding to the different overall thicknesses of the suspension fillers in Example 4 are respectively made into 0.5 mm, 1.5 mm, 3.0 mm and 4.0 mm for effect testing.

[0082] The ratio of the maximum depth of the depression to the maximum opening width of the depression is preferably in the range of 2:1-1:2. The ratio of the suspension fillers with different overall thicknesses in Example 4 is manufactured to be 1:1 for effect testing.

[0083] The suspended fillers prepared in Examples 1-4 were tested for fluidization effects using sludge from aerobic tanks in municipal sewage treatment plants and a staged dosing strategy. The results are shown in Table 1.

[0084] Table 1

[0085] As shown in Table 1, the time required for complete fluidization of suspended fillers of different thicknesses in different embodiments is different and is related to the dosing strategy. But in general, each embodiment of the present disclosure has the function of quickly completing fluidization. All embodiments can complete the fluidization of fillers with a tank filling rate of more than 50% within 24 hours, which has obvious advantages compared with traditional commercially available rigid suspended fillers (commercially available rigid suspended fillers require 7-15 days or even longer to fully fluidize). The rapid fluidization of suspended fillers provides more opportunities for microorganisms to attach and form biofilms in the initial stage, which will shorten the startup time of the reactor.

[0086] The suspended fillers manufactured as described in Examples 1-4 were continuously tested for ammonia nitrogen removal using an MBBR reactor. As the hydraulic load fluctuated in stages (ammonia nitrogen concentration ≥ 50 mg / L, HRT ≤ 6 h), the ammonia nitrogen removal rates were all above 95%. The maximum thickness of the biofilm was strictly controlled by the maximum depth of the depression formed by the wavy skeleton, which avoided the uncontrolled growth of the biofilm caused by hydraulic load fluctuations and ensured the effective activity of the biofilm.

[0087] The main limitations of all currently available MBBR suspended media are slow initial fluidization and the inability to control biofilm growth within an effective range. The thickness of the biofilm required for active function is far less than currently available MBBR suspended media designs. Commercially available rigid suspended media assume that the biofilm grows only on its protected inner surface. In reality, as hydraulic loads fluctuate, the biofilm can overgrow and clog internal channels. This creates an anaerobic zone or inactivity for the microorganisms within, leaving only the surface exposed to the liquid environment, significantly reducing the effective membrane area. The efficiency of these traditional suspended media depends entirely on the free growth of the biofilm, and operational stability cannot be effectively guaranteed.

[0088] The MBBR suspended filler disclosed herein controls the maximum thickness of biofilm growth. Even when the hydraulic load fluctuates arbitrarily, the biofilm grows all over the cavity enclosed by the wavy skeleton and the partition ribs or the recessed area of ​​the wavy skeleton. At this time, the thickness of the biofilm layer is still an effective thickness for functioning. Therefore, the maximum depth of the recess must be strictly controlled within the effective range. For thicker film layers, it will evolve into a dead zone of traditional MBBR suspended fillers, which will greatly reduce the performance and stability of the filler.

[0089] The design of the optimal maximum depth range of the depression depends on the specific application process and application scenario. When applied to a multi-stage AO-MBBR process, different levels of AO sections have different metabolic functions for nitrogen. For the AO section that is mainly responsible for nitrification but has lower requirements for denitrification, it is more effective to choose a depression depth of less than 0.5mm. This is related to the control of the oxygen transfer depth. When the maximum depth of the depression is less than 0.05mm, the biomass that can be enriched in the depression is extremely limited and cannot support the formation of a relatively complete nitrogen metabolism closed loop. Similarly, when applied in a mud-film mixing process, priority is given to the enrichment of activated sludge in order to obtain a higher sludge load. At this time, the maximum depth of the depression should be greater than 1.0mm, thereby achieving effective enrichment of functional microorganisms under the corresponding biochemical process.

[0090] The significant structural features of the present invention are the wavy skeleton, the depth of the depression and the size of its opening, which provide a structural basis for the dynamic replacement of the biofilm under different hydraulic load fluctuations, and also lay a structural foundation for the control of the liquid temporary storage rate. The wavy skeleton structure design is more conducive to hydraulic shear control, thereby maintaining high biofilm activity under any hydraulic load fluctuation. It should be emphasized that the effectiveness of the dynamic replacement of the biofilm depends on the ratio of the maximum depth of the depression to the maximum opening width of the depression. This ratio must be in the range of 5:1-1:10, and most preferably in the range of 2:1-1:2 to achieve effective dynamic replacement of the biofilm.

[0091] Compared to existing MBBR suspended filler technologies, the present disclosure offers the following advantages: it provides a suspended filler that enables rapid fluidization, low-energy operation, and stable biofilm formation. This suspended filler significantly shortens fluidization time during the initial addition phase, paving the way for rapid reactor startup. Furthermore, it can control biofilm growth, avoiding or mitigating system instability issues caused by various hydraulic load fluctuations during actual operation. This offers an advantageous solution for MBBR and other biofilm processes, and possesses broad application value.

[0092] The present disclosure has been specifically described in the above implementation examples, but is not limited to the specific forms described above. The scope of the present disclosure is defined by the claims. In addition to the specific implementation examples described above, other implementation examples may also fall within the scope of the claims. Improvements and innovations based on the present disclosure should be included in the scope of protection determined by the claims of the present disclosure. Industrial Applicability

[0093] The present invention provides a fast-fluidizing and stably biofilm-forming suspended filler, which has wide application value in the field of sewage biological treatment.

Claims

1. A floating packing, characterized in that, The structure of the suspended packing includes a wave-shaped skeleton, and two adjacent rows of wave-shaped skeletons are mirror images of each other and arranged staggeredly.

2. The floating packing according to claim 1, characterized in that, Two adjacent rows of skeletons are connected through the contact points of adjacent wave-shaped skeletons, and the sunken area of the wave surface serves as the biofilm growth area.

3. The suspended packing according to claim 1, characterized in that, The structure of the suspended packing further includes partition ribs. Two adjacent rows of wave-shaped skeletons are connected through the partition ribs, and the chamber formed by the sunken part of the wave surface and the partition ribs serves as the biofilm growth area.

4. The suspended packing according to claim 1, characterized in that, The wave-shaped skeleton structure of the suspended packing includes one or a combination of more than one of pure sine wave shape, sine wave shape, square wave shape, triangular wave shape, half wave shape, trapezoidal wave shape, and honeycomb wave shape.

5. The floating packing according to claim 1, characterized in that, The thickness of the suspended packing is 0.1 - 7.0 mm.

6. The floating packing according to claim 3, characterized in that, The thickness of the partition rib is ≤1.0 mm.

7. The floating packing according to claim 1, wherein The wave surface thickness of the wave-shaped skeleton is 0.05 - 2.0 mm; The wave surface width of the wave-shaped skeleton is 0.05 - 50 mm.

8. The floating packing according to claim 2 or 3, characterized in that, The maximum depth of the sunken area is 0.05 - 5.0 mm.

9. The floating packing according to claim 1, wherein The ratio of the maximum depth to the maximum opening width of the sunken area is 5:1 - 1:

10.

10. The floating packing according to claim 1, characterized in that, The shape of the suspended packing includes one or more of saddle shape, C shape, S shape, hexagon, circle, or rectangle, or a non-planar shape with a notch.

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