A system and method for hierarchical resource utilization of excess sludge in an activated sludge process

Abstract

The application discloses a kind of activated sludge process residual sludge grading resource utilization system and method, including spiral deslagging device, scale plate sand remover, hydrocyclone group, residual sludge pool and heavy sludge storage pool in order along sludge flow direction.Sludge is entered into hydrocyclone group after deslagging and sand removing, and is sorted into aging sludge and high-quality dense activated sludge rich in organic matter;Aging sludge is discharged into residual sludge pool and dehydrated, and upper clear water is reused for washing, and lower sludge is discharged for disposal;High-quality dense activated sludge enters into conditioning mixing box in heavy sludge storage pool, and forms activated sludge zooglea through water distribution, medium liquid spraying mixing and turbulent reaction, and returns to the front end of anaerobic tank or anoxic tank of activated sludge process.The application integrates deslagging, sand removing, hydrocyclone and medium conditioning, realizes high-quality sludge recovery and in-situ expansion of biochemical system, reduces sludge discharge amount, improves treatment capacity, is stable in operation, and is suitable for upgrading and reconstruction of sewage treatment plant.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment and sludge resource utilization technology, and in particular to a system and method for the classification, sorting and resource utilization of residual sludge from activated sludge processes. Specifically, it involves a process that combines pretreatment for sand and slag removal, wet media conditioning and hydraulic cyclone classification to recover high-quality activated sludge and organic matter components from the sludge, while removing fine, aged sludge and inorganic sand particles, thereby achieving sludge reduction and expansion and efficiency enhancement of the biochemical system. Background Technology

[0002] The activated sludge process (anaerobic-anoxic-aerobic) is one of the most widely used biological nitrogen and phosphorus removal processes in urban wastewater treatment plants. During the operation of the activated sludge system, in-situ proliferation of influent pollutants and microorganisms generates a large amount of excess sludge. Traditional treatment methods typically involve discharging large amounts of excess sludge into a sludge treatment system, where it is concentrated, dewatered, and then transported off-site for landfill or incineration. This not only results in high treatment and disposal costs but also wastes the active microorganisms and organic matter in the sludge.

[0003] In existing technologies, hydrocyclones have been gradually applied in the field of sludge classification, utilizing centrifugation to achieve differential separation of sludge components. For example, patent document CN118145801A discloses a system that uses a hydrocyclone process to release carbon sources within sludge, releasing extracellular polymers through cyclone shearing to replenish carbon sources. However, this scheme only focuses on carbon source release and does not address the effective classification and reuse of high-quality sludge and aged sludge. Patent document CN202511267294 proposes a method for screening and controlling dense activated sludge, setting up two sets of hydrocyclones to respectively achieve sludge densification and dewatering performance enhancement. However, it targets the pre-dewatering conditioning of concentrated sludge and does not combine it with the reflux expansion of the biological system.

[0004] Traditional sludge and sand removal systems mostly employ separate arrangements of bar screens and grit chambers at the wastewater inlet, resulting in large floor space and low integration. Chemical dosing systems generally use conventional three-tank dissolving devices, but lack precise control and mixing structures for the addition of sludge conditioning media, leading to significant fluctuations in sludge properties.

[0005] Overall, current activated sludge processes for waste sludge treatment have the following shortcomings:

[0006] 1. A large amount of residual sludge is discharged externally, and high-quality active microbial resources are not recycled and utilized;

[0007] 2. The accumulation of aged, fine sludge and inorganic sand particles in the system limits the properties of the sludge and exacerbates equipment wear;

[0008] 3. The pretreatment, conditioning and grading units are isolated from each other, resulting in low equipment integration and insufficient operational stability.

[0009] Therefore, developing a compact, reliable activated sludge graded resource utilization system with structural and process innovation as its core has significant engineering application value for wastewater treatment plant pollution reduction, carbon reduction, quality improvement, and capacity expansion. Summary of the Invention

[0010] The purpose of this invention is to overcome the shortcomings of the prior art and provide a system and method for the graded resource utilization of waste sludge from activated sludge process. Through an integrated process route of "slag and sand removal pretreatment - hydraulic cyclone grading and recovery - wet media conditioning", high-quality activated sludge and organic matter components in the waste sludge are recovered and returned to the biological system, while fine crushed aged sludge and heavy sand particles are discharged. This reduces the amount of sludge discharged and increases the effective sludge concentration in the biological tank, thereby achieving in-situ expansion of the treatment capacity of the activated sludge process.

[0011] The present invention adopts the following technical solution:

[0012] A system for the graded resource utilization of waste sludge from an activated sludge process, comprising, in sequence along the sludge flow direction:

[0013] Spiral slag removers are distributed above the sludge inlet storage tank;

[0014] The scale-type sand remover is arranged obliquely below the spiral slag remover, and has a slag and sand discharge port at the top, which is located on the side away from the hydrocyclone group.

[0015] The hydrocyclone assembly is connected to the sludge inlet pump and the sludge inlet storage tank. The overflow outlet extends into the excess sludge tank, and the bottom outlet discharges high-quality, dense activated sludge rich in organic matter into the heavy sludge storage tank.

[0016] The waste sludge tank is equipped with a buffer zone, a water collection zone and a sedimentation zone. The overflow outlet is located in the buffer zone, the water collection zone is located on one side of the buffer zone, and the water collection zone is equipped with inclined pipes and a water collection trough. The sedimentation zone is located below the water collection zone and the buffer zone and is connected to the waste sludge pump and sludge dewatering equipment.

[0017] The heavy sludge storage tank contains a conditioning and mixing box. From top to bottom, the conditioning and mixing box is divided into a water distribution zone, a chemical mixing zone, and a stable effluent zone. The water distribution zone contains a sludge feed pipe and a water distributor. The sludge feed pipe is connected to the bottom outlet of the hydrocyclone assembly. The chemical mixing zone contains a chemical replenishment device, which is connected to a dosing pump. The bottom of the heavy sludge storage tank is returned to the front end of the anaerobic or anoxic tank of the activated sludge process via a high-quality sludge pump.

[0018] In the activated sludge process waste sludge classification and resource utilization system, the spiral sludge remover is equipped with a spiral bar screen. The spiral bar screen includes a bar screen, a sludge discharge channel, a support roller group, and a drive motor. The bar screen is rolled on the support roller group. The drive motor is independently arranged on the side of the support roller group and a drive wheel is installed at the output end. The drive wheel and the end of the bar screen are driven together. The sludge discharge channel is set inside the bar screen and a scraper is set at the top. A sludge discharge port is set at the tail of the sludge discharge channel.

[0019] In the activated sludge process waste sludge classification and resource utilization system, a guide plate is provided between the apron sand remover and the spiral slag remover, and the slag and sand discharge port of the apron sand remover is equipped with a flushing pipe connected to the water collection tank.

[0020] In the activated sludge process waste sludge classification and resource utilization system, the hydrocyclone group consists of multiple hydrocyclones connected in parallel. Each hydrocyclone includes an upper cylindrical body and a lower conical body. The cylindrical body has a tangential feed inlet on its side wall and an overflow pipe at the top center. The feed inlets of each hydrocyclone are connected to the outlet of the pump group via a water distributor. The overflow ports of each hydrocyclone are connected to the overflow manifold and lead to the waste sludge tank. The bottom of the conical body has an underflow port, and the underflow ports of each hydrocyclone are connected to the underflow manifold and the sludge feed pipe.

[0021] In the activated sludge process waste sludge classification and resource utilization system, the overflow pipe is inserted into the cylindrical body to a depth of 0.65 to 0.75 times the height of the cylindrical body, and the ratio of the overflow pipe diameter to the inner diameter of the cylindrical body is 0.25 to 0.35.

[0022] In the activated sludge process waste sludge classification and resource utilization system, the supplementary components include a spray pipe network and a turbulence plate arranged sequentially from top to bottom. Spray heads are evenly distributed on the spray pipe network, and the spray pipe network is connected to a booster pump.

[0023] In the activated sludge process waste sludge classification and resource utilization system, the spray head includes a pipe body connected to the spray pipe network. A pressure-bearing movable body is fixedly installed inside the pipe body. One end of the pressure-bearing movable body extends to the outside of the pipe body, and multiple rotating strips are rotatably installed on the outside of this end and distributed circumferentially. A linkage rod is rotatably installed on the body of the rotating strip. A movable ring is connected to the free end of the linkage rod. The movable ring is movably fitted on the outside of the pressure-bearing movable body. A limit ring is installed on the outside of the body of the pressure-bearing movable body. A spring is provided between the limit ring and the movable ring and is fitted on the outside of the pressure-bearing movable body. Flexible sheets are installed on the multiple rotating strips.

[0024] In the activated sludge process waste sludge classification and resource utilization system, the pressurized moving body has a moving head at one end of the pipe body. The moving head has multiple reagent ports around its circumference. The body of the pressurized moving body is equipped with an inner section. The outer wall of the inner section and the inner wall of the pipe body form a dosing area. The thickness of the dosing area is greater than or equal to the radial depth of the reagent ports on the moving head.

[0025] In the activated sludge process waste sludge classification and resource utilization system, the multiple reagent ports are all arranged at an angle and in the same direction. The movable ring is provided with a cone head at one end opposite the spring. The cone head can enter the inner side of the pipe body to open and close the dosing area.

[0026] A method for using a system for the graded resource utilization of waste sludge from an activated sludge process includes the following steps:

[0027] Step 1: The excess sludge discharged from the secondary sedimentation tank of the activated sludge process is pumped into the spiral sludge separator by the sludge pump, where the slag and sand are removed by the scale plate sand remover, and then flows by gravity into the sludge storage tank.

[0028] Step 2: The sludge after removing slag and sand is sent to the hydrocyclone group for grading and sorting by the sludge pump. The overflow port of the hydrocyclone group discharges the aged sludge and sends it to the residual sludge tank. The underflow outlet discharges high-quality dense activated sludge rich in organic matter and sends it to the water distribution area through the sludge feed pipe.

[0029] Step 3: The aged and finely broken sludge enters the buffer zone through the overflow main pipe, and then flows into the sedimentation zone. The clear water after sedimentation is collected by the water collection tank and sent into the flushing pipe as flushing water for the slag and sand discharge port of the abrasive plate sand remover. The sludge in the sedimentation zone is pumped out by the excess sludge pump and sent to the sludge dewatering equipment for treatment. A portion of the excess sludge after dewatering is returned to the sludge storage tank, with a return amount of 5-15%.

[0030] Step 4: High-quality dense activated sludge is evenly dispersed by the water distributor in the water distribution zone and flows into the mixing zone. In the mixing zone, the sludge falling into the mixing zone fully convects and collides with the sprayed medium and liquid, and forms a low-speed turbulent sludge mixture through the turbulence plate. The medium and sludge flocs react fully, promoting the aggregation of high-quality sludge flocs to form activated sludge flocs.

[0031] The activated sludge flocs enter the bottom of the heavy sludge tank from the steady flow effluent zone and are then returned to the front end of the anaerobic or anoxic tank of the activated sludge process via a high-quality sludge pump.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. This application uses hydrocyclone grading to divide the excess sludge into two parts: high-quality activated sludge and aged sludge. The high-quality part is returned to the biological treatment system to continue to play a role, while only the aged part is discharged for disposal. This can reduce the amount of sludge discharged by 20% to 35% and significantly reduce the cost of sludge treatment and disposal.

[0034] 2. This application can effectively increase the MLSS concentration in the biological treatment tank by recirculating high-quality activated sludge. Without increasing the volume of the biological treatment tank, the wastewater treatment capacity of the activated sludge system can be increased by 15% to 25%. It is suitable for upgrading and expanding existing wastewater treatment plants, with low civil engineering investment and short renovation cycle.

[0035] 3. This application integrates the bar screen and grit removal function into the same tank, which enhances the pretreatment effect and removes a large amount of fibrous and inert inorganic matter in the sludge; at the same time, the equipment has a high degree of factory prefabrication, small footprint, and convenient on-site installation.

[0036] 4. This application incorporates a conditioning and mixing zone within the heavy sludge tank. Utilizing the inherent energy of hydraulic pressure, it achieves highly efficient mixing of the reagents and sludge, replacing the traditional single-point mixing method. This significantly increases the contact area between the reagents and sludge, preventing reagent clumping and uneven mixing in certain areas. Simultaneously, multiple sets of guide plates are arranged within the zone, forming a reciprocating flow channel. The sludge mixture enters a low-speed turbulent state within the channel, ensuring both sufficient reaction between the sorting medium and sludge flocs, promoting the aggregation of high-quality sludge flocs, and preventing high-speed shearing from damaging the activated sludge flocs.

[0037] 5. This application can flexibly adapt to fluctuations in different water quality, water quantity and sludge properties by adjusting multiple parameters such as feed pressure, underflow opening and media dosage. The SOUR of high-quality sludge after grading is significantly improved, SVI is reduced, and aged sludge is effectively removed, but the VSS / SS ratio is higher. This helps to maintain the sludge activity and settling performance of the activated sludge system and reduce the risk of sludge bulking. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the system structure of this application.

[0039] Figure 2 This is a schematic diagram of the spiral slag remover of this application.

[0040] Figure 3 This is a schematic diagram of the structure of the residual sludge tank in this application.

[0041] Figure 4 This is a schematic diagram of the heavy sludge storage tank of this application.

[0042] Figure 5 This is a top view of the sprinkler network of this application.

[0043] Figure 6 This is a schematic diagram of the structure of the spray head of this application.

[0044] Figure 7 This is a schematic diagram of the structure of the pressure-bearing moving body of this application.

[0045] Figure 8 This is a schematic diagram of the active ring structure of this application.

[0046] In the diagram: 100, Spiral slag remover; 110, Spiral bar screen; 111, Screen cylinder; 112, Slag discharge channel; 113, Support roller assembly; 114, Drive motor; 115, Drive wheel; 116, Scraper; 200, Sludge inlet storage tank; 300, Scale-type sand remover; 310, Slag and sand discharge port; 320, Flushing pipe; 400, Hydrocyclone assembly; 410, Overflow main pipe; 420, Underflow main pipe; 500, Excess sludge tank; 510, Buffer zone; 520, Water collection area; 521, Inclined pipe; 522, Water collection trough; 530, Sedimentation zone. 600. Heavy sludge storage tank; 610. Conditioning and mixing tank; 611. Sludge feed pipe; 612. Water distributor; 620. Mixing zone; 630. Stabilized flow effluent zone; 640. Chemical replenishment component; 641. Spray pipe network; 642. Turbulence plate; 643. Spray head; 6431. Pipe body; 6432. Tilting bar; 6433. Linkage rod; 6434. Spring; 6435. Limiting ring; 6436. Pressurized moving body; 64361. Moving head; 64362. Inward retraction part; 64363. Chemical inlet; 700. Sludge dewatering equipment. Detailed Implementation

[0047] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0048] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0049] Example 1

[0050] like Figure 1 As shown, a system for the graded resource utilization of waste sludge from an activated sludge process includes, in sequence along the sludge flow direction:

[0051] Spiral slag remover 100 is located above sludge inlet storage tank 200;

[0052] The scale-type sand remover 300 is arranged obliquely below the spiral slag remover 100, and the top is provided with a slag and sand discharge port 310, which is located on the side away from the hydrocyclone group 400.

[0053] The hydrocyclone assembly 400 is connected to the sludge inlet pump and the sludge inlet storage tank 200. The overflow outlet extends into the excess sludge tank 500, and the bottom outlet discharges high-quality, dense activated sludge rich in organic matter into the heavy sludge storage tank 600.

[0054] The waste sludge tank 500 includes a buffer zone 510, a water collection zone 520, and a sedimentation zone 530. The overflow outlet is located within the buffer zone 510. The water collection zone 520 is located on one side of the buffer zone 510 and contains an inclined pipe 521 and a water collection trough 522. The sedimentation zone 530 is located below the water collection zone 520 and the buffer zone 510 and is connected to the waste sludge pump and sludge dewatering equipment 700. Aged and finely broken sludge flows into the buffer zone 510 via the overflow main and then into the sedimentation zone 530. After sedimentation, the upper layer of clear water is collected by the water collection trough 520 and used as flushing water for the sludge and sand discharge outlet 310. The lower layer of sludge... The excess sludge is pumped to the sludge dewatering equipment 700 for treatment. A portion of the dry sludge from the sludge dewatering equipment 700 is then returned to the upstream sludge storage tank 200, with a return amount of 5-15%, preferably 10%. Under the action of hydraulic shear force in subsequent processes, the dewatered excess sludge will decompose into sludge aggregates and flocculent sludge of varying particle sizes. Larger aggregates serve as carriers for microorganisms, while smaller aggregates act as nuclei, accelerating microbial aggregation. Therefore, returning a portion of the dewatered sludge to the system as a conditioning medium promotes sludge aggregation, thereby improving conditioning efficiency and reducing sludge discharge.

[0055] The heavy sludge storage tank 600 has a conditioning and mixing tank 650 installed inside. The conditioning and mixing tank 650 is arranged from top to bottom as follows: water distribution zone 610, chemical mixing zone 620, and stable flow effluent zone 630. The water distribution zone 610 is equipped with a sludge feed pipe 611 and a water distributor 612. The sludge feed pipe 611 is connected to the bottom outlet of the hydrocyclone group 400. The chemical mixing zone 620 is equipped with a chemical replenishment device 640, which is connected to a chemical dosing pump. The bottom of the heavy sludge storage tank 600 is returned to the front end of the anaerobic or anoxic tank of the activated sludge process via a high-quality sludge pump.

[0056] In the system described, such as Figure 2As shown, the spiral slag remover 100 is equipped with a spiral bar screen 110. The spiral bar screen 110 includes a bar screen 111, a slag discharge channel 112, a support roller group 113, and a drive motor 114. The bar screen 111 has a screen gap of 1-3 mm. The bar screen 111 is rolled on the support roller group 113. The drive motor 114 is independently arranged on the side of the support roller group 113 and a drive wheel 115 is installed at the output end. The drive wheel 115 and the end of the bar screen 111 form a transmission cooperation. The slag discharge channel 112 is set inside the bar screen 111 and a scraper 116 is set at the top. The surface of the scraper 116 is covered with a wear-resistant polyurethane layer. The tail end of the slag discharge channel 112 is provided with a slag discharge port, which scrapes off the fibers, hair, and large suspended solids intercepted by the bar screen and discharges them axially through the slag discharge port.

[0057] In the system described, such as Figure 1 As shown, a guide plate 320 is provided between the scale-type sand remover 300 and the spiral slag remover 100. The slag and sand discharge port 310 of the scale-type sand remover 300 is equipped with a flushing pipe connected to the water collection tank 522. When muddy water containing sand and gravel passes through, it is intercepted and retained on the scale plates, while the lighter sand and sludge are carried away with the water flow, achieving rapid enrichment and separation of sand and gravel. At the same time, the recycled water from the residual sludge tank 500 can effectively and quickly flush the surface of the scale plates through the flushing pipe.

[0058] In the system described, such as Figure 1 As shown, the hydrocyclone group 400 is composed of multiple hydrocyclones connected in parallel. Each hydrocyclone includes a cylindrical body at the top and a conical body at the bottom. The cylindrical body has a tangential feed inlet on its side wall and an overflow pipe at the top center. The feed inlets of each hydrocyclone are connected to the outlet of the pump group via a water distributor. The overflow ports of each hydrocyclone are connected to the overflow manifold 410 and lead to the residual sludge tank 500. The bottom of the conical body has an underflow port. The underflow ports of each hydrocyclone are connected to the underflow manifold 420 and the sludge feed pipe 611.

[0059] In the system described above, the overflow pipe is inserted into the cylindrical body to a depth of 0.65 to 0.75 times the height of the cylindrical body, and the ratio of the overflow pipe diameter to the inner diameter of the cylindrical body is 0.25 to 0.35.

[0060] In the system described above, the supplementary medicine component 640 includes a spray pipe network 641 and a turbulence plate 642 arranged sequentially from top to bottom. Spray heads 643 are evenly distributed on the spray pipe network 641, and the spray pipe network 641 is connected to a pressure pump.

[0061] The system operates according to the following steps:

[0062] Step 1: The excess sludge discharged from the secondary sedimentation tank of the activated sludge process is pumped into the spiral sludge separator 100 by the sludge pump, where the slag and sand are removed by the scale plate sand remover 300, and then flows by gravity into the sludge storage tank 200.

[0063] Step 2: The sludge after removing slag and sand is sent to the hydrocyclone group 400 by the sludge pump for grading and sorting. The overflow port of the hydrocyclone group 400 discharges the aged sludge and sends it to the residual sludge tank 500. The underflow outlet discharges high-quality dense activated sludge rich in organic matter and sends it to the water distribution area 610 through the sludge feed pipe 611.

[0064] Step 3: The aged and finely broken sludge enters the buffer zone 510 through the overflow main pipe 410, and then flows into the sedimentation zone 530. The clear water after sedimentation is collected by the water collection tank 522 and sent into the flushing pipe as the flushing water for the slag and sand discharge port 310 of the scale sand remover 300. The sludge in the sedimentation zone 530 is pumped out by the residual sludge pump and sent to the sludge dewatering equipment 700 for treatment. A portion of the residual sludge after dewatering is returned to the sludge storage tank 200, with a return amount of approximately 10%.

[0065] Step 4: High-quality dense activated sludge is evenly dispersed in the water distribution zone 610 by the water distributor 612 and flows into the mixing zone 620. In the mixing zone 620, the sludge falling into the mixing zone fully convects and collides with the sprayed medium and liquid, and forms a low-speed turbulent sludge mixture through the turbulence plate 642. The medium and sludge flocs react fully, promoting the aggregation of high-quality sludge flocs to form activated sludge flocs.

[0066] The activated sludge flocs enter the bottom of the heavy sludge tank from the steady flow effluent zone 630, and are then returned to the front end of the anaerobic or anoxic tank of the AAO process by a high-quality sludge pump.

[0067] Example 2

[0068] In the system described, such as Figures 5 to 8As shown, the spray head 643 includes a pipe body 6431 connected to the spray pipe network 641. A pressure-bearing movable body 6436 is fixedly installed inside the pipe body 6431. One end of the pressure-bearing movable body 6436 extends to the outside of the pipe body 6431, and a plurality of rotating bars 6432 are rotatably installed on the outside of this end and distributed circumferentially. A linkage rod 6433 is rotatably installed on the body of the rotating bar 6432. A movable ring 6434 is connected to the free end of the linkage rod 6433. The movable ring 6434 can move. A limit ring 6435 is installed on the outside of the pressure-bearing movable body 6436. A spring 6437 is provided between the limit ring 6435 and the movable ring 6434, and the spring 6437 is fitted on the outside of the pressure-bearing movable body 6436. Flexible plates are installed on the outside of the multiple flip bars 6432 and the outside of the movable ring 6434 to seal the spring 6437, limit ring 6435, linkage rod 6433 and flip bars 6432 inside.

[0069] The pressure-bearing movable body 6436 is fixed to one end of the tube body 6431 and has a movable head 64361. The movable head 64361 has a plurality of medicine ports 64363 arranged circumferentially. The body of the pressure-bearing movable body 6436 is equipped with an inner portion 64362. The outer wall of the inner portion 64362 and the inner wall of the tube body 6431 form a medicine addition area. The thickness of the medicine addition area is greater than or equal to the radial depth of the medicine ports 64363 on the movable head 64361.

[0070] The multiple drug ports 64363 are all arranged at an angle and in the same direction. The end of the movable ring 6436 facing away from the spring is provided with a conical head. The conical head can enter the inside of the tube body 6431 to open and close the drug application area. At the same time, when the top opening of the drug application area is opened, the medium liquid is guided to the outside.

[0071] When using medium pressure for delivery, the medium liquid pushes the movable ring 6434 outward from the dosing area inside the pipe body 6431 when the set delivery pressure overcomes the outward movement resistance of the movable ring 6434. This opens the dosing area and allows the medium liquid to be delivered into the mixing zone. When the medium liquid is delivered from the agent outlet 64343, it enters the mixing zone in a swirling state. The movable ring 6434 moves outward under pressure, opening the top of the dosing area. During the outward movement, it compresses the spring 6437, causing the linkage rod 6433 to push the flip bar 6432 to flip from facing upward. At this time, the top of the dosing area is open, and the medium liquid will form convection with the falling sludge. When the addition of the agent stops, it can be reset under the action of the spring 6437, wrapping the flexible sheet around the top opening of the pipe body 64 to prevent sludge particles from clogging the pipe body 6431.

[0072] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. The substitutions may be replacements of some structures, devices, or method steps, or they may be complete technical solutions. Equivalent substitutions or modifications made to the technical solutions and inventive concepts of the present invention should all be covered within the scope of protection of the present invention.

Claims

1. A system for the graded resource utilization of waste sludge from an activated sludge process, characterized in that, Along the sludge flow direction, the following are included in sequence: Spiral slag remover (100) is located above the sludge inlet storage tank (200); The scale-type sand remover (300) is arranged obliquely below the spiral slag remover (100) and has a slag and sand discharge port (310) at the top. The slag and sand discharge port (310) is located on the side away from the hydrocyclone group (400). The hydrocyclone assembly (400) is connected to the sludge inlet pump and the sludge inlet storage tank (200), and the overflow outlet extends into the excess sludge tank (500). The bottom outlet discharges high-quality, dense activated sludge rich in organic matter into the heavy sludge storage tank (600). The waste sludge tank (500) is equipped with a buffer zone (510), a water collection zone (520) and a sedimentation zone (530). The overflow outlet is located in the buffer zone (510). The water collection zone (520) is located on one side of the buffer zone (510). An inclined pipe (521) and a water collection trough (522) are installed in the water collection zone (520). The sedimentation zone (530) is located below the water collection zone (520) and the buffer zone (510) and is connected to the waste sludge pump and the sludge dewatering equipment (700). The heavy sludge storage tank (600) is equipped with a conditioning and mixing tank (650). The conditioning and mixing tank (650) is arranged from top to bottom as follows: water distribution zone (610), chemical mixing zone (620) and stable flow effluent zone (630). The water distribution zone (610) is equipped with a sludge feed pipe (611) and a water distributor (612). The sludge feed pipe (611) is connected to the bottom outlet of the hydrocyclone group (400). The chemical mixing zone (620) is equipped with a chemical replenishing device (640). The chemical replenishing device (640) is connected to a chemical dosing pump. The bottom of the heavy sludge storage tank (600) is returned to the front end of the anaerobic tank or anoxic tank of the activated sludge process via a high-quality sludge pump.

2. The system for graded resource utilization of waste sludge from activated sludge process according to claim 1, characterized in that, The spiral slag remover (100) is equipped with a spiral bar screen (110). The spiral bar screen (110) includes a bar screen (111), a slag discharge channel (112), a support roller group (113), and a drive motor (114). The bar screen (111) is rolled on the support roller group (113). The drive motor (114) is independently arranged on the side of the support roller group (113) and a drive wheel (115) is installed at the output end. The drive wheel (115) and the end of the bar screen (111) form a transmission cooperation. The slag discharge channel (112) is set inside the bar screen (111) and a scraper (116) is set at the top. A slag discharge port is set at the tail of the slag discharge channel (112).

3. The system for graded resource utilization of waste sludge from activated sludge process according to claim 1, characterized in that, A guide plate (320) is provided between the scale-type sand remover (300) and the spiral slag remover (100), and a flushing pipe connected to the water collection tank (522) is installed at the slag and sand discharge port (310) of the scale-type sand remover (300).

4. The system for graded resource utilization of waste sludge from activated sludge process according to claim 1, characterized in that, The hydrocyclone assembly (400) consists of multiple hydrocyclones connected in parallel. Each hydrocyclone includes a cylindrical body at the top and a conical body at the bottom. The cylindrical body has a tangential feed inlet on its side wall and an overflow pipe at the top center. The feed inlets of each hydrocyclone are connected to the outlet of the pump assembly via a water distributor. The overflow ports of each hydrocyclone are connected to the overflow manifold (410) and lead to the residual sludge tank (500). The bottom of the conical body has an underflow port. The underflow ports of each hydrocyclone are connected to the underflow manifold (420) and the sludge feed pipe (611).

5. A system for graded resource utilization of waste sludge from an activated sludge process according to claim 4, characterized in that, The overflow pipe is inserted into the cylindrical body to a depth of 0.65 to 0.75 times the height of the cylindrical body, and the ratio of the overflow pipe diameter to the inner diameter of the cylindrical body is 0.25 to 0.

35.

6. The system for graded resource utilization of waste sludge from activated sludge process according to claim 1, characterized in that, The supplementary medicine component (640) includes a spray pipe network (641) and a turbulence plate (642) arranged sequentially from top to bottom. Spray heads (643) are evenly distributed on the spray pipe network (641), and the spray pipe network (641) is connected to a pressure pump.

7. The system for graded resource utilization of waste sludge from activated sludge process according to claim 6, characterized in that, The spray head (643) includes a pipe body (6431) connected to the spray pipe network (641). A pressure-bearing movable body (6436) is fixedly installed inside the pipe body (6431). One end of the pressure-bearing movable body (6436) extends to the outside of the pipe body (6431), and multiple rotating bars (6432) are rotatably installed on the outside of this end and distributed circumferentially. A linkage rod (6433) is rotatably installed on the body of the rotating bar (6432). 3) The free end is connected to a movable ring (6434), which is movably fitted on the outside of the pressure-bearing movable body (6436). A limit ring (6435) is installed on the outside of the body of the pressure-bearing movable body (6436). A spring (6437) is provided between the limit ring (6435) and the movable ring (6434), and the spring (6437) is fitted on the outside of the pressure-bearing movable body (6436). Flexible sheets are installed on multiple flip bars (6432).

8. A system for graded resource utilization of waste sludge from activated sludge process according to claim 7, characterized in that, The pressure-bearing movable body (6436) is fixed to one end of the tube body (6431) and has a movable head (64361). The movable head (64361) has a plurality of drug ports (64363) arranged circumferentially. The body of the pressure-bearing movable body (6436) is equipped with an inner section (64362). The outer wall of the inner section (64362) and the inner wall of the tube body (6431) form a drug addition area. The thickness of the drug addition area is greater than or equal to the radial depth of the drug ports (64363) on the movable head (64361).

9. A system for graded resource utilization of waste sludge from an activated sludge process according to claim 8, characterized in that, The multiple drug ports (64363) are all arranged at an angle and in the same direction. The end of the movable ring (6436) facing away from the spring is provided with a cone head, which can enter the inside of the tube body (6431) to open and close the drug application area.

10. A method for using a system for the graded resource utilization of waste sludge from an activated sludge process, characterized in that, Includes the following steps: Step 1: The excess sludge discharged from the secondary sedimentation tank of the activated sludge process is pumped into the spiral sludge remover (100) by the sludge pump, and the sludge and sand are removed by the scale plate sand remover (300) and flow into the sludge storage tank (200) by gravity. Step 2: The sludge after removing slag and sand is sent to the hydrocyclone group (400) by the sludge pump for grading and sorting. The overflow port of the hydrocyclone group (400) discharges the aged sludge and sends it to the residual sludge tank (500). The underflow outlet discharges high-quality dense activated sludge rich in organic matter through the sludge feed pipe (611) and sends it to the water distribution area (610). Step 3: The aged and finely broken sludge enters the buffer zone (510) through the overflow main pipe (410) and then flows into the sedimentation zone (530). The clear water after sedimentation is collected by the water collection tank (522) and sent into the flushing pipe as the flushing water for the slag and sand discharge port (310) of the scale sand remover (300). The sludge in the sedimentation zone (530) is pumped out by the residual sludge pump and sent to the sludge dewatering equipment (700) for treatment. A portion of the residual sludge after dewatering is returned to the sludge storage tank (200), with a return amount of 5-15%. Step 4: High-quality dense activated sludge is evenly dispersed in the water distribution zone (610) by the water distributor (612) and flows into the mixing zone (620). In the mixing zone (620), the sludge falling into the mixing zone (620) fully convects and collides with the sprayed medium and liquid, and forms a low-speed turbulent sludge mixture through the turbulence plate (642). The medium and sludge flocs react fully, promoting the aggregation of high-quality sludge flocs to form activated sludge flocs. The activated sludge flocs enter the bottom of the heavy sludge tank from the steady flow effluent zone (630) and are then returned to the front end of the anaerobic or anoxic tank of the AAO process by a high-quality sludge pump.

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