Activated sludge screening and granulating process and device and use method

Abstract

The invention discloses an activated sludge screening granulation process and device and a using method, and relates to the technical field of sewage biochemical treatment. The device comprises a screen component, the screen component comprises at least one screen plate, screen holes are formed in the surface of the screen plate, and a base is installed below the screen plate; the aeration turbulence component comprises an aeration pipe mounted on the upper surface of the base, the surface of the aeration pipe is uniformly sleeved with an aeration disc mounting seat, an aeration disc is mounted above the aeration disc mounting seat, and an aeration pipe connector is mounted at the end part of the aeration pipe; the local turbulence stirring part comprises at least one stirring part, and the stirring part is arranged on any side of the sieve plate and located above the aeration disc; the multi-stage sieve holes are adopted, the sieve plate is divided into an upper area, a middle area and a lower area, the hole diameters are sequentially reduced, accurate grading interception can be achieved according to the particle size, the aeration disc releases tiny bubbles to form turbulent flow, shearing force is generated to destroy the flocculent sludge structure, microorganisms are promoted to secrete EPS, particle densification is accelerated, and the sludge volume index is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of biochemical sewage treatment, and specifically to an activated sludge screening and granulation process, a device and a use method. Background Art

[0002] In the aerobic granular sludge process, the particle size distribution of granular sludge directly affects its settling performance (characterized by the sludge volume index SVI) and biodegradation efficiency. Large-sized particles (>200μm) can settle quickly and maintain system stability due to their high density and low SVI; while small-sized particles (<100μm) are mostly flocculent and easily lost with the effluent, resulting in uncontrolled sludge age and reduced system efficiency.

[0003] At present, small particles are generally removed by shortening the settling time: in SBR (Sequencing Batch Reactor) or SBR-like reactors, the settling time is shortened so that larger, dense granular sludge is first settled, while small particles and flocculent sludge are carried away with the effluent. The main problem with this method may be that the settling time is too short, resulting in some medium-sized particles not being completely settled, thus affecting the screening effect.

[0004] In addition, short-term sedimentation may have strict requirements on operating conditions, such as sludge concentration, water flow rate, etc. If these parameters are not properly controlled, it may lead to unstable screening efficiency. Increase hydraulic shear force: Increase hydraulic shear force through water inlet strategy, eliminate small particles that are not resistant to shear, and promote the growth of impact-resistant granular sludge. Problems with this method may include that excessive shear force may destroy the existing particle structure, causing the particles to disintegrate, but increasing the number of small particles.

[0005] After searching, the utility model with publication number CN218931912U proposes an activated sludge screening device for sewage treatment, comprising: a first hydrocyclone, having a first sludge inlet, a first heavy phase outlet and a first light phase outlet, the first sludge inlet is used to be connected to the outlet of the residual sludge discharge system; a second hydrocyclone, having a second sludge inlet, a second heavy phase outlet and a second light phase outlet, the second sludge inlet is connected to the first heavy phase outlet, the second heavy phase outlet is a sludge outlet for discharging residual sludge, and the second light phase outlet is a reflux outlet connected to the biochemical system; the device can perform continuous screening to ensure the proportion of organic component sludge in the activated sludge, but the particle size of the granular sludge is not screened, and small granular sludge, i.e., flocculent sludge, is easy to be lost, resulting in the problem of uncontrolled sludge age and decreased system efficiency. Summary of the invention

[0006] In order to solve the problems that in the aerobic granular sludge process, the effluent of the biochemical tank lacks a screening device, the sludge particle size cannot be further increased, resulting in poor sedimentation performance, especially in winter, and the system treatment effect is poor, the present invention proposes an activated sludge screening granulation process, device and usage method to solve the above problems.

[0007] In traditional activated sludge treatment, large particle sludge has a high density and large mass, and its sedimentation speed is relatively fast, usually depositing at the bottom of the reactor; while small particle or flocculent sludge has a low density and loose structure, and is easily suspended in the upper layer or lost with the effluent. However, through the synergistic effect of multi-stage screening, aeration turbulence and stirring intensification, the device of the present invention changes the separation mode that simply relies on natural sedimentation and realizes more efficient particle classification and interception.

[0008] An activated sludge screening granulation device, including a screen component, the screen component includes at least one sieve plate, the surface of the sieve plate is provided with sieve holes, and a base is installed below the sieve plate;

[0009] An aeration turbulence component, the aeration turbulence component includes an aeration pipe installed on the upper surface of the base, an aeration disc mounting seat is evenly sleeved on the surface of the aeration pipe, an aeration disc is installed above the aeration disc mounting seat, and an aeration pipe interface is installed at the end of the aeration pipe.

[0010] A local turbulence stirring component, the local turbulence stirring device includes at least one stirring component, and the stirring component is arranged on any side of the sieve plate and above the aeration disc.

[0011] Furthermore, setting the sieve plate significantly reduces the loss rate of small particle sludge, stabilizes the sludge age, and improves the system treatment efficiency, but flocculent sludge will accumulate on the surface of the sieve plate and cause blockage;

[0012] Furthermore, setting the aeration turbulence component, using the tiny bubbles generated by the aeration disc to form an upward turbulence, applying a shear force to the flocculent sludge, destroying the loose floc structure of the flocculent sludge, and promoting particle densification; at the same time, the turbulence pushes the sludge to be evenly distributed to avoid local accumulation;

[0013] Furthermore, setting the local turbulence stirring component to form a local eddy current, enhancing the collision frequency between particles, accelerating the granulation process, transforming flocculent sludge into granular sludge, and reducing the loss of small particle sludge.

[0014] Furthermore, the sieve plate includes an upper area, a middle area and a lower area, and the aperture of the sieve holes decreases by zone from top to bottom. For example: the aperture of the sieve holes on the surface of the upper area is 300 - 400 μm, the aperture of the sieve holes 3 on the surface of the middle area is 150 - 200 μm, and the aperture of the sieve holes 3 on the surface of the lower area is 50 - 100 μm.

[0015] Furthermore, the aperture of the sieve plate decreases step by step from top to bottom. The physical size limitation of the sieve holes directly intercepts particles of corresponding particle sizes. Large particles are intercepted by the larger-aperture sieve in the upper area and stay above the sieve plate; small particles need to pass through the smaller-aperture sieve holes in the lower area, but cannot pass through due to the aperture limitation and are finally intercepted below the sieve plate.

[0016] Furthermore, through gradient screening, large particles are intercepted in the upper area and further densified, medium particles partially settle in the middle area, and small particles are precisely intercepted by the sieve holes in the lower area, avoiding the loss of flocculent sludge with the effluent.

[0017] Furthermore, the upward air flow generated by aeration exerts an upward buoyancy force on large particles. However, due to their large mass, large particles are still intercepted by the sieve holes above the sieve plate, while small particles are suspended in the water flow due to the buoyancy force and are finally filtered by the sieve holes in the lower area.

[0018] Furthermore, the upward bubbles generated by the aeration disk form a hydraulic shear force and turbulence. Combined with the mixing effect of the stirring blades, the flocculent sludge is broken up and the densification of large particles is promoted.

[0019] Furthermore, the sieve plate is inclined at an angle of 30 - 45° to the horizontal plane, and the inclination direction is towards the direction of the sieve plate close to the aeration disk.

[0020] Furthermore, the inclination direction is towards the aeration area. The sludge slides along the surface of the sieve plate under the action of gravity and water flow; the water flow scouring effect reduces the sludge adhesion on the surface of the sieve holes, and the inclination angle prolongs the particle residence time, enhancing the screening efficiency while reducing the clogging probability.

[0021] Furthermore, when the sieve plate is inclined, the sludge slides along the surface of the sieve plate, the water flow scouring effect is enhanced, large particles gather in the upper area of the sieve plate, and small particles are carried by the water flow to the lower sieve holes.

[0022] Furthermore, the shape of the sieve holes is a diamond-shaped hole or a long-strip-shaped hole, and the edges of the sieve holes are rounded.

[0023] Furthermore, raised patterns are provided inside the sieve holes in the lower area.

[0024] The raised patterns increase the surface area and adsorption force, enhancing the interception ability for small particles; the rounded edges reduce the wall hanging of fiber impurities and lower the clogging risk.

[0025] Furthermore, it also includes a connecting piece. Sliding grooves are provided on both sides of the connecting piece, and the cross-section of the connecting piece is in the shape of an I-beam. Limiting blocks are fixedly connected to both sides of the sieve plate. When the sieve plate is connected to the connecting piece, the limiting blocks move linearly along the inner surface of the sliding grooves and extend into the base.

[0026] Furthermore, multiple sieve plates are connected through the connecting piece

[0027] Furthermore, a hook ring is fixedly connected to the top surface of the sieve plate, and the surface of the sieve plate is covered with a composite coating.

[0028] Furthermore, the high wear resistance and hydrophobicity of the composite coating reduce biofilm adhesion, prevent corrosion, and reduce the frequency of manual cleaning;

[0029] Furthermore, the stirring component comprises a stirring motor, an output end of the stirring motor is connected to a stirring rod, the size of the stirring rod is the same as the size of a single sieve plate, and stirring blades are evenly sleeved on the surface of the stirring rod.

[0030] Furthermore, the leading edge of the stirring blade is arc-shaped, the trailing edge of the stirring blade is a tapered surface, the surface of the stirring blade is provided with a fish fin corrugated texture, and the stirring blade is made of carbon fiber reinforced composite material.

[0031] Furthermore, the curved leading edge reduces the resistance, and the tapered trailing edge accelerates the water flow, forming a local vortex, increasing the collision frequency between particles, and accelerating the granulation process.

[0032] Furthermore, the size of the stirring blades drawn in the accompanying drawings is for reference only, and the specific size needs to be calculated based on the specific working efficiency.

[0033] Furthermore, when the biochemical pool is relatively wide, stirring motors may be respectively arranged on both sides of the biochemical pool, and stirring rods may be arranged opposite to each other.

[0034] Furthermore, carbon fiber reinforced composite materials have low density and high strength, and their lightweight design reduces motor load and stirring energy consumption; the fish fin ripple texture optimizes fluid mechanics and further improves energy efficiency;

[0035] Working principle:

[0036] The sieve plate is divided into three areas: upper, middle and lower, and the apertures decrease successively.

[0037] Upper zone: intercepts large particles of sludge and uses the physical restrictions of the sieve holes to prevent them from passing through.

[0038] Middle zone: Some medium particles settle, and the remaining particles continue to migrate downward.

[0039] Lower area: small particles are accurately intercepted through the raised patterns inside the sieve holes and the surface adsorption force.

[0040] As the sludge flows from top to bottom, it is screened step by step to ensure that particles of different sizes are separated efficiently, and the extremely fine flocculent sludge that is not intercepted is discharged with the effluent.

[0041] The diameter of the microbubbles released by the aeration pipe is 0.5 - 2 mm, forming an upward airflow and turbulence; the shear force generated when the bubbles rise destroys the loose structure of the flocculent sludge, prompting the microorganisms to secrete extracellular polymeric substances (EPS); uniformly dispersing the sludge, avoiding local accumulation, and improving the screening uniformity; while the general function of conventional aeration is to increase the dissolved oxygen content in the water and promote the growth of aerobic organisms.

[0042] The stirring paddle is designed with fin corrugated textures. It reduces the water flow resistance, forms local vortices, enhances the collision frequency between particles, has an arc-shaped leading edge and a tapered trailing edge, optimizes the hydrodynamics, accelerates the combination and densification of particles, is driven by a stirring motor with adjustable speed, and dynamically adjusts the mixing intensity according to the sludge concentration to promote granulation.

[0043] EPS secretion and particle densification

[0044] Biological action:

[0045] The aeration shear force stimulates the microorganisms to secrete EPS polysaccharides, proteins, etc., which act as "adhesives" to wrap the sludge particles.

[0046] Physical action:

[0047] The stirring vortices cause the particles to collide repeatedly, and EPS gradually fills the pores, forming a dense structure.

[0048] Multi-stage granulation process

[0049] Stage 1: Floc breakup and nucleus formation

[0050] The aeration shear force breaks up the flocculent sludge, forming initial particle nuclei.

[0051] Stage 2: Particle growth and stratification

[0052] Upper area: The large particles continuously receive aeration shear and stirring above the sieve plate, the EPS secretion increases, and the particle size gradually increases.

[0053] Lower area: After the small particles are intercepted, they are further fused through hydraulic turbulence and collision to form medium-sized particles.

[0054] Stage 3: Densification and stabilization

[0055] The particles repeatedly experience shear, collision, and EPS wrapping during the screening process, and finally form dense and highly sedimentable particles.

[0056] The usage method of the activated sludge screening granulation device includes the following steps:

[0057] Step 1, Connect the aeration system: Connect the aeration pipe to the external gas source through the aeration pipe interface, and check whether the aeration pipe valve is in the closed state.

[0058] Step 2. Adjust the inclination angle of the sieve plate:

[0059] Vertically set; fix the sieve plate vertically on the base 11 through the chute of the connecting piece, ensuring that the limit block 102 is completely embedded in the base.

[0060] Inclined setting of 30° - 45°; loosen the fixing bolt of the connecting piece, adjust the inclination angle of the sieve plate to the target value such as 40°, ensure that the sieve plate is inclined towards the aeration disc direction, and lock the bolt.

[0061] Step 3. Start the aeration system: Slowly open the valve of the aeration pipe, adjust the air pressure to 0.1 - 0.3 MPa, and observe whether tiny bubbles are evenly released on the surface of the aeration disc.

[0062] Step 4. Start the stirring component: Turn on the stirring motor, set the rotation speed to 50 - 100 rpm, and the stirring paddle 4 starts to rotate, ensuring that the fin ripple texture of the paddle is consistent with the water flow direction.

[0063] Step 5. Multi-stage screening: The screening aperture in the upper area is 300 - 400 μm: Large particle sludge > 200 μm is intercepted on the upper area of the sieve plate, and some medium particles of 100 - 200 μm flow downward with the water flow;

[0064] The screening aperture in the middle area is 150 - 200 μm: Medium particles settle partially in the middle area, and the remaining particles continue to migrate downward;

[0065] The screening aperture in the lower area is 50 - 100 μm: Small particles < 100 μm are intercepted by the lower area sieve holes 3, and the flocculent sludge is discharged through the sieve holes with the effluent.

[0066] Step 6. Recovery of granular sludge: The screened granular sludge is collected through the sludge discharge pipe, and the sludge discharge valve is regularly opened to discharge the dense particles, and the sludge discharge frequency is controlled to be once every 2 hours.

[0067] Step 7. Adjustment of aeration intensity: Adjust the air pressure through the aeration pipe valve according to the screening effect;

[0068] If there are too many small particle residues, increase the air pressure to 0.3 MPa to enhance the hydraulic shear force;

[0069] If the particle breakage rate is too high, reduce the air pressure to 0.1 MPa to reduce the turbulence intensity.

[0070] Step 8. Cleaning of sieve holes:

[0071] After each shift, turn off the mud inlet and aeration systems, and use a high-pressure water gun to rinse the sieve holes in the reverse direction from the bottom of the sieve plate, with a focus on cleaning the raised texture area inside the lower area sieve holes.

[0072] Compared with the prior art, the present invention has the following beneficial effects:

[0073] 1. Precise classification screening to reduce the loss of small - particle sludge: The device adopts a multi - level sieve - hole design. The sieve plate is divided into upper, middle, and lower zones, and the pore sizes decrease in sequence. It can accurately classify and intercept according to particle size or select sieve holes with different pore sizes according to the treatment stage. Large particles are intercepted and compacted in the upper zone, medium - sized particles partially settle in the middle zone, and small particles are intercepted in the lower zone. Moreover, the raised patterns of the sieve holes enhance adsorption. This significantly reduces the loss rate of small particles, stabilizes the sludge age, and improves the system stability. At the same time, the optimized sieve - hole structure reduces the risk of wall - hanging and blockage, protecting the integrity of the particles.

[0074] 2. Promote particle densification and improve sedimentation performance: The aeration disk releases tiny bubbles to form turbulence, generating shear force to break the flocculent sludge structure, prompting microorganisms to secrete EPS to accelerate particle densification, reducing the sludge volume index, and increasing the sedimentation speed. The carbon - fiber stirring paddle has a unique design, reducing water flow resistance, forming eddies to promote particle collision and fusion, optimizing fluid dynamics, shortening the granulation cycle, and enhancing the mechanical strength of the particles.

[0075] 3. Anti - blockage design to reduce maintenance costs: The inclined sieve plate enables the sludge to slide along the surface under the action of gravity and water flow. The water flow scouring reduces sludge adhesion, decreasing the blockage frequency and extending the maintenance interval. The polyurethane - ceramic composite coating is wear - resistant, corrosion - resistant, and hydrophobic, reducing biofilm adhesion, preventing sieve - hole corrosion, extending the service life of the sieve plate, and reducing maintenance costs.

[0076] 4. Energy conservation and consumption reduction and operation flexibility: The carbon - fiber stirring paddle has a low density and high strength, reducing the motor load and energy consumption. The dynamic adjustment of aeration controls the air pressure as needed, avoiding excessive energy consumption. The inclination angle of the sieve plate and the stirring speed are adjustable, capable of adapting to different sludge concentrations and treatment scales, reducing the comprehensive energy consumption and having strong applicability.

[0077] 5. Process stability and shock - resistance ability: The large - particle sludge after screening has a dense structure and strong resistance to hydraulic shock. The system's tolerance to fluctuations in influent flow rate and pollutant concentration is improved, and the effluent suspended solids are stable. By monitoring the particle size distribution and dynamically adjusting parameters, the screening conditions are optimized in real - time to ensure long - term operation stability. Description of the Drawings

[0078] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0079] Figure 1 It is the installation schematic diagram of the activated sludge screening and granulation device;

[0080] Figure 2It is the structure diagram a of the activated sludge screening and granulation device;

[0081] Figure 3 It is the structure diagram b of the activated sludge screening and granulation device;

[0082] Figure 4 It is the structure diagram c of the activated sludge screening and granulation device;

[0083] Figure 5 It is the structure diagram d of the activated sludge screening and granulation device;

[0084] Figure 6 It is the top view of the activated sludge screening and granulation device;

[0085] Figure 7 It is the side view with the sieve plate arranged obliquely.

[0086] In the figure:

[0087] 1. Sieve plate; 101. Hook ring; 102. Limit block;

[0088] 2. Connecting piece;

[0089] 3. Sieve hole;

[0090] 4. Stirring paddle;

[0091] 5. Aeration pipe;

[0092] 6. Aeration disk mounting seat;

[0093] 7. Aeration disk;

[0094] 8. Stirring rod;

[0095] 9. Stirring motor;

[0096] 10. Pool wall;

[0097] 11. Base;

[0098] 12. Baffle;

[0099] 13. Aeration pipe interface;

[0100] 14. Reaction tank;

[0101] 15. Sludge discharge pipe;

[0102] 16. Sludge discharge pipe;

[0103] 17. Aeration pipe valve. Specific implementation method

[0104] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0105] The application principle of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0106] Embodiment 1

[0107] As Figures 1-6 shown, the activated sludge screening and granulation device includes a screen component. The screen component includes at least one screen plate 1. Sieve holes 3 are formed on the surface of the screen plate 1. A base 11 is installed below the screen plate 1. The base 11 is installed at the water outlet of the reaction tank 14 and is immersed below the water surface.

[0108] An aeration turbulence component. The aeration turbulence component includes an aeration pipe 5 installed on the upper surface of the base 11. Aeration disk mounting seats 6 are evenly sleeved on the surface of the aeration pipe 5. An aeration disk 7 is installed above the aeration disk mounting seat 6. An aeration pipe interface 13 is installed at the end of the aeration pipe 5.

[0109] A local turbulence stirring component. The local turbulence stirring device includes at least one stirring component. The stirring component is arranged on any side of the screen plate 1 and above the aeration disk 7.

[0110] The setting of the screen plate 1 significantly reduces the loss rate of small-particle sludge, the particle size of small-particle sludge, stabilizes the sludge age, and improves the treatment efficiency of the system. However, flocculent sludge will accumulate on the surface of the screen plate 1 and cause blockage;

[0111] The setting of the aeration turbulence component uses the tiny bubbles generated by the aeration disk 7 to form an upward turbulence, applies a shear force to the flocculent sludge, destroys the loose floc structure of the flocculent sludge, and promotes the densification of particles; at the same time, the turbulence promotes the uniform distribution of sludge and avoids local accumulation;

[0112] The setting of the local turbulence stirring component forms a local eddy current, enhances the collision frequency between particles, accelerates the granulation process, converts the flocculent sludge into granular sludge, and reduces the loss of small-particle sludge.

[0113] Embodiment 2

[0114] As Figures 1-7 shown, on the basis of Embodiment 1, for the activated sludge screening and granulation device, the screen plate 1 includes an upper area, a middle area and a lower area. The aperture 3 of the sieve holes decreases in a zonal manner from top to bottom. Taking the aperture of the sieve holes 3 on the surface of the upper area as 300-400 μm, the aperture of the sieve holes 3 on the surface of the middle area as 150-200 μm, and the aperture of the sieve holes 3 on the surface of the lower area as 50-100 μm as an example;

[0115] The aperture of the sieve plate 1 gradually decreases from top to bottom. The physical size limit of the sieve holes directly intercepts particles of corresponding particle sizes. Large particles > 200μm are intercepted by the larger-aperture sieves 300 - 400μm in the upper area and stay above the sieve plate. Small particles < 100μm need to pass through the smaller-aperture sieve holes 50 - 100μm in the lower area, but cannot pass due to the aperture limit and are finally intercepted below the sieve plate.

[0116] Through gradient screening, large particles are intercepted in the upper area and further densified, medium particles partially settle in the middle area, and small particles are precisely intercepted by the sieve holes in the lower area, preventing flocculent sludge from flowing out with the effluent.

[0117] The upward air flow generated by aeration exerts an upward buoyancy force on large particles. However, due to their large mass, large particles are still intercepted by the sieve holes above the sieve plate, while small particles are suspended in the water flow due to the buoyancy force and are finally filtered by the sieve holes in the lower area.

[0118] The rising bubbles generated by the aeration disk 7 form hydraulic shear force and turbulence. Combined with the mixing action of the stirring paddle 4, the flocculent sludge is broken up and the densification of large particles is promoted.

[0119] The sieve plate 1 is inclined at an angle of 30 - 45° to the horizontal plane, and the inclined direction is towards the direction of the sieve plate 1 approaching the aeration disk 7.

[0120] The inclined direction is towards the aeration area. The sludge slides along the surface of the sieve plate under the action of gravity and water flow. The water flow scouring effect reduces the sludge attachment on the surface of the sieve holes. The inclined angle prolongs the particle residence time, enhancing the screening efficiency while reducing the probability of blockage.

[0121] When the sieve plate 1 is inclined, the sludge slides along the surface of the sieve plate 1. The water flow scouring effect is enhanced. Large particles gather in the upper area of the sieve plate 1, while small particles are carried by the water flow to the lower sieve holes 3.

[0122] The shape of the sieve hole 3 is a diamond-shaped hole or a long-strip-shaped hole, and the edges of the sieve hole 3 are rounded.

[0123] Convex-shaped patterns are provided inside the sieve holes 3 in the lower area.

[0124] The convex patterns increase the surface area and adsorption force, enhancing the interception ability for small particles. The rounded edges reduce the hanging of fiber impurities on the wall, reducing the risk of blockage.

[0125] It also includes a connecting piece 2. Sliding grooves are provided on both sides of the connecting piece 2. The cross-section of the connecting piece 2 is in an I-shaped structure. Limited blocks 102 are fixedly connected to both sides of the sieve plate 1. When the sieve plate 1 is connected to the connecting piece 2, the limited blocks 102 move linearly along the inner surface of the sliding grooves and extend into the base.

[0126] Multiple sieve plates 1 are connected through the connecting piece 2

[0127] A hook ring 101 is fixedly connected to the top surface of the sieve plate 1, and a composite coating is covered on the surface of the sieve plate 1.

[0128] The high wear resistance and hydrophobicity of the composite coating reduce biofilm attachment, prevent corrosion, and reduce the frequency of manual cleaning;

[0129] The stirring component includes a stirring motor 9. The output end of the stirring motor 9 is connected to a stirring rod 8. The size of the stirring rod 8 is the same as that of a single sieve plate 1. Stirring blades 4 are evenly sleeved on the surface of the stirring rod 8.

[0130] The leading edge of the stirring blade 4 is arc-shaped, the trailing edge of the stirring blade 4 is a tapered curved surface, a fin ripple texture is arranged on the surface of the stirring blade 4, and the material of the stirring blade 4 is a carbon fiber reinforced composite material.

[0131] The arc-shaped leading edge reduces resistance, the tapered trailing edge accelerates the water flow, forms local eddies, enhances the collision frequency between particles, and accelerates the granulation process.

[0132] The carbon fiber reinforced composite material has low density and high strength. The lightweight design reduces the motor load and the stirring energy consumption is reduced; the fin ripple texture optimizes the hydrodynamic performance and further improves the energy efficiency;

[0133] Example 3

[0134] As Figures 1-7 shown: The activated sludge screening and granulation device includes a screen component. The screen component includes at least one sieve plate 1. Sieve holes 3 are formed on the surface of the sieve plate 1. A base 11 is installed below the sieve plate 1;

[0135] An aeration and turbulence component. The aeration and turbulence component includes an aeration pipe 5 installed on the upper surface of the base 11. Aeration disk mounting seats 6 are evenly sleeved on the surface of the aeration pipe 5. An aeration disk 7 is installed above the aeration disk mounting seat 6. An aeration pipe interface 13 is installed at the end of the aeration pipe 5.

[0136] A local turbulence stirring component. The local turbulence stirring device includes at least one stirring component. The stirring component is arranged on any side of the sieve plate 1 and above the aeration disk 7.

[0137] Setting the sieve plate 1 significantly reduces the loss rate of small particle sludge. The particle size of small particle sludge is <100 μm, stabilizes the sludge age, and improves the treatment efficiency of the system. However, flocculent sludge will accumulate on the surface of the sieve plate 1 and cause blockage;

[0138] Setting the aeration and turbulence component, using the tiny bubbles generated by the aeration disk 7 to form an upward turbulence, applying a shear force to the flocculent sludge, destroying the loose floc structure of the flocculent sludge, and promoting the densification of particles; at the same time, the turbulence promotes the uniform distribution of sludge and avoids local accumulation;

[0139] A local turbulent stirring component is set to form a local eddy current, enhance the collision frequency between particles, accelerate the granulation process, transform the flocculent sludge into granular sludge, and reduce the loss of small particle sludge.

[0140] The sieve plate 1 includes an upper region, a middle region and a lower region, and the aperture 3 of the sieve holes decreases in a zonal manner from top to bottom. Taking the aperture of the sieve holes 3 on the surface of the upper region as 300 - 400 μm, the aperture of the sieve holes 3 on the surface of the middle region as 150 - 200 μm, and the aperture of the sieve holes 3 on the surface of the lower region as 50 - 100 μm as an example;

[0141] The aperture of the sieve plate 1 decreases step by step from top to bottom. The physical size limitation of passing through the sieve holes directly intercepts the particles with corresponding particle sizes. Large particles > 200 μm: are intercepted by the sieve holes with larger apertures of 300 - 400 μm in the upper region and stay above the sieve plate; small particles < 100 μm: need to pass through the sieve holes with smaller apertures of 50 - 100 μm in the lower region, but cannot pass through due to the aperture limitation and are finally intercepted below the sieve plate.

[0142] Through gradient screening, large particles are intercepted by the upper region and further densified, medium particles partially settle in the middle region, and small particles are precisely intercepted by the sieve holes in the lower region, avoiding the loss of flocculent sludge with the effluent.

[0143] The upward air flow generated by aeration exerts an upward buoyancy force on the large particles, but the large particles are still intercepted by the sieve holes above the sieve plate due to their large mass, while the small particles are suspended in the water flow due to the buoyancy force and are finally filtered by the sieve holes in the lower region.

[0144] The upward bubbles generated by the aeration disk 7 form a hydraulic shear force and turbulence, combined with the mixing action of the stirring blade 4, to break up the flocculent sludge and promote the densification of large particles.

[0145] The sieve plate 1 is inclined at an angle of 30 - 45° to the horizontal plane, and the inclined direction is towards the direction of the sieve plate 1 close to the aeration disk 7.

[0146] The inclined direction is towards the aeration zone, and the sludge slides along the surface of the sieve plate under the action of gravity and water flow; the water flow scouring effect reduces the sludge adhesion on the surface of the sieve holes, and the inclined angle prolongs the particle residence time, enhancing the screening efficiency while reducing the probability of blockage.

[0147] When the sieve plate 1 is inclined, the sludge slides along the surface of the sieve plate 1, the water flow scouring effect is enhanced, large particles gather in the upper region of the sieve plate 1, and small particles are carried by the water flow to the lower sieve holes 3.

[0148] The shape of the sieve holes 3 is a diamond-shaped hole or a long strip-shaped hole, and the edges of the sieve holes 3 are rounded.

[0149] Convex-shaped patterns are arranged inside the sieve holes 3 located in the lower region.

[0150] The raised patterns increase the surface area and adsorption capacity, enhancing the ability to retain small particles; the rounded edges reduce the adhesion of fiber impurities to the wall, reducing the risk of clogging.

[0151] It also includes a connecting member 2, which has sliding grooves on both sides. The cross-section of the connecting member 2 is I-shaped. The two sides of the sieve plate 1 are fixedly connected with limiting blocks 102. When the sieve plate 1 is connected to the connecting member 2, the limiting blocks 102 move linearly along the inner surface of the sliding groove and extend into the base.

[0152] Connect multiple sieve plates 1 through connecting piece 2

[0153] A hook ring 101 is fixedly connected to the top surface of the sieve plate 1 , and the surface of the sieve plate 1 is covered with a composite coating.

[0154] The high wear resistance and hydrophobicity of the composite coating reduce biofilm adhesion, prevent corrosion, and reduce the frequency of manual cleaning;

[0155] The stirring component comprises a stirring motor 9 , the output end of the stirring motor 9 is connected to a stirring rod 8 , the size of the stirring rod 8 is the same as the size of a single sieve plate 1 , and the surface of the stirring rod 8 is evenly sleeved with stirring blades 4 .

[0156] The front edge of the stirring blade 4 is arc-shaped, the rear edge of the stirring blade 4 is a tapered curved surface, the surface of the stirring blade 4 is provided with a fish fin corrugated texture, and the stirring blade 4 is made of carbon fiber reinforced composite material.

[0157] The arc-shaped leading edge reduces resistance, and the tapered trailing edge accelerates water flow, forming local vortices, increasing the frequency of collisions between particles and accelerating the granulation process.

[0158] Carbon fiber reinforced composite materials have low density and high strength. The lightweight design reduces motor load and stirring energy consumption. The fish fin corrugated texture optimizes fluid mechanics and further improves energy efficiency.

[0159] Example 4

[0160] The method for using the activated sludge screening and granulation device comprises the following steps:

[0161] Step 1, connect the aeration system: connect the aeration pipe 5 to the external air source through the aeration pipe interface 13, check whether the aeration pipe valve 17 is in a closed state, the stirring motor 9 is fixedly installed on the outside of the pool wall 10, and a water retaining plate 12 is set at the water inlet of the water outlet weir.

[0162] Step 2: Adjust the inclination angle of sieve plate 1:

[0163] The sieve plate 1 is vertically fixed to the base 11 through the slide groove of the connecting member 2, ensuring that the limit block 102 is completely embedded in the base.

[0164] Set it at an inclination of 30° to 45°; loosen the fixing bolts of the connecting piece 2, adjust the inclination angle of the sieve plate to the target value such as 40°, ensure that the sieve plate inclines towards the aeration disc 7, and lock the bolts.

[0165] Step 3. Start the aeration system: Slowly open the valve 17 of the aeration pipe, adjust the air pressure to 0.1 - 0.3 MPa, and observe whether tiny bubbles are evenly released on the surface of the aeration disc 7.

[0166] Step 4. Start the stirring component: Turn on the stirring motor 9, set the rotation speed to 50 - 100 rpm, and the stirring paddle 4 starts to rotate, ensuring that the fin ripple texture of the paddle is consistent with the water flow direction.

[0167] Step 5. Multi - stage screening: The screening aperture in the upper area is 300 - 400 μm: Large - particle sludge > 200 μm is intercepted in the upper area of the sieve plate, and some medium - particle sludge with a size of 100 - 200 μm flows downward with the water flow.

[0168] The screening aperture in the middle area is 150 - 200 μm: Medium - particle sludge partially settles in the middle area, and the remaining particles continue to migrate downward.

[0169] The screening aperture in the lower area is 50 - 100 μm: Small - particle sludge < 100 μm is intercepted by the lower - area sieve holes 3, and the flocculent sludge is discharged through the sieve holes along with the effluent.

[0170] Step 6. Recovery of granular sludge: The screened granular sludge is collected through the sludge discharge pipe 15, regularly open the sludge discharge valve 16 to discharge the dense particles, and control the sludge discharge frequency to once every 2 hours.

[0171] Step 7. Adjust the aeration intensity: According to the screening effect, adjust the air pressure through the valve 17 of the aeration pipe;

[0172] If there are too many small - particle residues, increase the air pressure to 0.3 MPa to enhance the hydraulic shear force;

[0173] If the particle breakage rate is too high, reduce the air pressure to 0.1 MPa to reduce the turbulence intensity.

[0174] Step 8. Clean the sieve holes: After each shift, turn off the mud inlet and aeration systems, and use a high - pressure water gun to rinse the sieve holes 3 from the bottom of the sieve plate 1 in the reverse direction, with a focus on cleaning the raised texture area inside the lower - area sieve holes.

[0175] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, in any regard, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention.

[0176] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. Activated sludge screening granulation process, characterized in that, It includes the following steps: X1. Screening treatment of activated sludge: Activated sludge particles of different particle sizes enter the outlet of the biochemical tank along with the water flow. The water flow passes through a barrier, which intercepts large particle sludge and part of the flocculent sludge, and part of the flocculent sludge flows out with the water flow; X2. Dispersing treatment of flocculent sludge: The tiny bubbles generated by the aeration turbulence component impact the flocculent sludge, break the flocculent sludge, form tiny sludge, and are fully mixed in water; X3. Granulation treatment of sludge: The crushed tiny sludge is suspended in water, and the local turbulence stirring component disturbs the water flow, so that the tiny sludge suspended in water collides and combines with each other to form large particle sludge.

2. Activated sludge screening and granulation device, characterized in that: A screen component, the screen component includes at least one screen plate (1), the surface of the screen plate (1) is provided with screen holes (3), and a base (11) is installed below the screen plate (1); It includes the aeration turbulence component described in claim 1, the aeration turbulence component includes an aeration pipe (5) installed on the upper surface of the base (11), an aeration disc mounting seat (6) is evenly sleeved on the surface of the aeration pipe (5), and an aeration disc (7) is installed above the aeration disc mounting seat (6); It includes the local turbulence stirring component described in claim 1, the local turbulence stirring device includes at least one stirring component, and the stirring component is arranged on any side of the screen plate (1) and above the aeration disc (7).

3. The activated sludge screening and granulation device according to claim 2, characterized in that: The screen plate (1) includes an upper area, a middle area and a lower area, the aperture of the screen holes (3) decreases by zone from top to bottom, the screen plate (1) is inclined at an angle of 30-45° to the horizontal plane, and the inclined direction is towards the direction of the screen plate (1) close to the aeration disc (7).

4. The activated sludge screening and granulation device according to claim 2, characterized in that: The shapes of the screen holes (3) in each zone can be independently selected as diamond-shaped holes or long strip-shaped holes, and the edges of the screen holes (3) are rounded.

5. The activated sludge screening and granulating device according to claim 4, characterized in that: Convex patterns are arranged inside the screen holes (3) in the lower area.

6. The activated sludge screening and granulation device according to claim 2, characterized in that: It also includes a connecting piece (2), both sides of the connecting piece (2) are provided with chutes, the cross-section of the connecting piece (2) is in the shape of an I, and limiting blocks (102) are fixedly connected to both sides of the screen plate (1). When the screen plate (1) is connected to the connecting piece (2), the limiting blocks (102) move linearly along the inner surface of the chute and extend into the base.

7. The activated sludge screening and granulation device according to claim 6, characterized in that: A hook ring (101) is fixedly connected to the top surface of the screen plate (1), and the surface of the screen plate (1) is covered with a composite coating.

8. The activated sludge screening and granulation device according to claim 1, characterized in that: The stirring component includes a stirring motor (9), the output end of the stirring motor (9) is connected with a stirring rod (8), the size of the stirring rod (8) is the same as the size of a single screen plate (1), and stirring blades (4) are evenly sleeved on the surface of the stirring rod (8).

9. The activated sludge screening and granulation device according to claim 8, characterized in that: The front edge of the stirring blade (4) is arc-shaped, the rear edge of the stirring blade (4) is a tapered curved surface, fish fin corrugated textures are arranged on the surface of the stirring blade (4), and the material of the stirring blade (4) is carbon fiber reinforced composite material.

10. Method for using an activated sludge screening and granulation device, characterized in that, It includes the following steps: Step 1. Connect the aeration system: Connect the aeration pipe (5) to an external air source through the aeration pipe interface (13), check whether the aeration pipe valve (17) is in the closed state. The stirring motor (9) is fixedly installed outside the pool wall (10), and a water baffle (12) is arranged at the water inlet of the weir. Step 2. Adjust the inclination angle of the sieve plate (1): Vertically set; Fix the sieve plate 1 vertically on the base (11) through the chute of the connecting piece (2), and ensure that the limit block (102) is completely embedded in the base; Inclined setting of 30° - 45°; Loosen the fixing bolts of the connecting piece (2), adjust the inclination angle of the sieve plate to the target value such as 40°, ensure that the sieve plate is inclined towards the aeration disc (7), and lock the bolts; Step 3. Start the aeration system: Slowly open the aeration pipe valve (17), adjust the air pressure to 0.1 - 0.3 MPa, and observe whether tiny bubbles are evenly released on the surface of the aeration disc (7); Step 4. Start the stirring component: Turn on the stirring motor (9), set the rotation speed to 50 - 100 rpm, and the stirring paddle (4) starts to rotate, ensuring that the fin corrugation texture of the paddle is consistent with the water flow direction; Step 5. Multi - stage screening: When the large - particle sludge flows with the water, it passes through the upper area, and the large - particle sludge is intercepted on the upper area of the sieve plate (1), and part of the medium - sized and small - sized sludge flows downward with the water; When part of the medium - sized particles settle in the middle area, the medium - sized particles pass through the screening aperture in the middle area and are intercepted, and the remaining particles continue to migrate downward; When the small - sized particles reach the lower - area sieve holes, they are intercepted by the lower - area sieve holes 3, and part of the un - intercepted flocculent sludge is discharged with the effluent through the sieve holes (3); Step 6. Granular sludge recovery: The screened granular sludge is collected through the sludge discharge pipe (15), regularly open the sludge discharge valve (16) to discharge the dense particles, and control the sludge discharge frequency to once every 2 hours; Step 7. Aeration intensity adjustment: Adjust the air pressure through the aeration pipe valve (17) according to the screening effect; If there are too many small - sized particle residues, increase the air pressure to 0.3 MPa to enhance the hydraulic shear force; If the particle breakage rate is too high, reduce the air pressure to 0.1 MPa to reduce the turbulence intensity; Step 8. Sieve hole cleaning: Shut down the sludge inlet and aeration systems, and use a high - pressure water gun to back - flush the sieve holes (3) from the bottom of the sieve plate (1), with a focus on cleaning the convex texture area inside the lower - area sieve holes.

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