Sewage treatment device and treatment method for water pollution control

Abstract

The invention relates to the technical field of sewage treatment, in particular to a sewage treatment device for water pollution control and a treatment method.The sewage treatment device for water pollution control comprises a box body, a primary filtering device, a microfiltering device, a backwashing device and a collecting box, and the primary filtering device for primarily filtering sewage is fixedly installed on one side in the box body; a microfiltration device is mounted on one side of the primary filtration device and is used for filtering sewage through a reverse osmosis membrane and periodically cleaning the interior of the microfiltration device; the backwashing assembly is fixedly mounted on one side of the box body, water produced after filtration of the microfiltration device is used as a backwashing water source, the outer wall of a filter cartridge is periodically washed through a high-pressure spray head, and internal and external collaborative cleaning is formed with internal mechanical cleaning; the backwashing assembly is used for washing the outside of the microfiltration device by using water filtered by the microfiltration device; a collecting box for collecting treated water is mounted on one side of the box body.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a wastewater treatment device and method for water pollution control. Background Technology

[0002] With increasingly stringent requirements for water pollution control, microfiltration technology has gained widespread application in areas such as advanced municipal wastewater treatment, industrial wastewater reuse, and reverse osmosis pretreatment due to its ability to effectively remove suspended solids, colloids, and some microorganisms. The core of a microfiltration device lies in the filtration performance and antifouling capabilities of the microfiltration membrane, which directly affect the effluent quality and system operational stability.

[0003] Most existing microfiltration devices employ fixed membrane module structures, where wastewater is filtered by passing through the membrane surface under pressure. However, in actual operation, membrane fouling remains a key bottleneck restricting the development of microfiltration technology: pollutants continuously deposit on the membrane surface and within the membrane pores, forming filter cake and gel layers, leading to a continuous increase in transmembrane pressure and a sharp decline in membrane flux. Traditional fouling control mainly relies on periodic backwashing or chemical cleaning, which uses clean water or chemical agents to backwash from the outside of the membrane to remove pollutants.

[0004] This single external backwashing mode has significant limitations: First, backwashing only cleans the outer surface of the membrane, and its effectiveness in removing contaminants deep within the membrane pores or firmly attached to the inner wall is limited, resulting in incomplete cleaning and low membrane performance recovery rates. Second, when contaminants form a dense filter cake layer on the inner side of the membrane, simple external backwashing cannot generate effective shear force, making deep cleaning difficult. Third, frequent backwashing and chemical cleaning require interruptions to the filtration process, causing frequent system start-ups and shutdowns, affecting continuous operation, and increasing operating costs and the risk of secondary contamination due to increased chemical consumption. Furthermore, existing technologies rarely include structural designs for simultaneous mechanical cleaning of the filter cartridge interior, leading to internal contamination accumulation becoming a major factor reducing membrane lifespan.

[0005] Therefore, the present invention provides a wastewater treatment device and treatment method for water pollution control, in order to solve the above-mentioned problems. Summary of the Invention

[0006] The technical problem this invention aims to solve is that the single external flushing mode has obvious limitations: First, backflushing can only clean the outer surface of the membrane, and its effect on removing pollutants that are deep inside the membrane pores or firmly attached to the inner wall of the membrane is limited, resulting in incomplete cleaning and low membrane performance recovery rate; Second, when pollutants form a dense filter cake layer on the inner side of the membrane, simple external flushing cannot generate effective shear force, making it difficult to achieve deep cleaning; Third, frequent backflushing and chemical cleaning require interruption of the filtration process, causing frequent system start-ups and shutdowns, affecting continuous operation capability, and increasing operating costs and the risk of secondary pollution due to the consumption of chemical agents.

[0007] This invention provides the following technical solution: a wastewater treatment device for water pollution control, comprising a tank, a primary filter, a microfiltration device, a backwashing device, and a collection tank. A primary filter for preliminary filtration of wastewater is fixedly installed on one side of the tank, serving as the supporting base for the entire device. The tank is internally divided into a primary filtration zone, a microfiltration zone, a product water zone, and a discharge zone. It is constructed of carbon steel or stainless steel and has an anti-corrosion coating on its inner wall. A stainless steel filter screen or wedge-shaped screen with a pore size of 50-100 μm is fixedly installed on one side of the tank to remove suspended solids and fibers with a particle size greater than 100 μm. The primary filtration unit removes impurities such as sand and gravel, protecting the subsequent microfiltration membrane. A microfiltration unit is installed on one side of the primary filtration unit, which is used to filter wastewater through the reverse osmosis membrane while periodically cleaning the inside of the microfiltration unit. The backwashing assembly is fixedly installed on one side of the tank, using the product water filtered by the microfiltration unit as the backwash water source, and periodically rinsing the outer wall of the filter cartridge through a high-pressure nozzle, forming a coordinated internal and external cleaning with the internal mechanical cleaning. The backwashing assembly uses the water filtered by the microfiltration unit to rinse the outside of the microfiltration unit. A collection tank for collecting the treated water is installed on one side of the tank.

[0008] Preferably, the microfiltration device includes a feed pipe, a limiting frame, a filter cartridge, a drive assembly, a transmission assembly, and a cleaning assembly. The feed pipe is fixedly installed on the limiting frame and connected to the primary filtration device. One end of the feed pipe is connected to the outlet flange of the primary filtration device, and the other end is inserted into the filter cartridge. It is made of UPVC or stainless steel with a pipe diameter of DN50-DN150. The limiting frame is symmetrically fixedly installed in the housing. The limiting frame adopts a bearing seat structure to support the filter cartridge and ensure its coaxiality of rotation. The bearing is selected from corrosion-resistant ceramic bearings or polytetrafluoroethylene bearings. The filter cartridge is rotatably installed on the limiting frame and connected to the feed pipe. The filter cartridge consists of two parts: a support frame and a microfiltration membrane. The support frame is a cylindrical frame made of 304 / 316L stainless steel or ABS engineering plastic with a diameter of Φ300-800mm, a length of 1500-3000mm, a wall thickness of 5-10mm, and permeable holes with a diameter of Φ5-10mm evenly distributed on the surface, with an opening rate of 30-50%. Microfiltration membrane: The membrane is coated onto the outer surface of the support frame via hot-melt welding or adhesive bonding. It is made of hydrophilic polyvinylidene fluoride (PVDF) or polyethersulfone (PES), with a pore size of 0.1-0.5 μm and a membrane thickness of 100-200 μm. It achieves cross-flow filtration under an operating pressure of 0.05-0.15 MPa. The drive assembly is installed in the middle of the filter cartridge and fixed to the top of the housing. The drive assembly drives the filter cartridge to rotate. The transmission assembly is installed inside the filter cartridge. While the filter cartridge rotates, the transmission assembly drives the cleaning assembly to periodically move within the filter cartridge to clean it. The cleaning assembly is also installed inside the filter cartridge.

[0009] Preferably, the drive assembly includes a fixed frame, a rectangular through slot, a drive motor, a drive pulley, a driven pulley, and a drive belt. The fixed frame is fixedly installed above the housing, either welded or bolted to the housing, and uses a welded structure of channel steel or angle steel to ensure the drive motor is securely installed. The drive motor, an IP55 protection-rated three-phase asynchronous motor, is fixedly installed on the fixed frame and equipped with a frequency converter for stepless speed regulation. The drive pulley, made of HT200 cast iron or aluminum alloy, is fixedly installed at the output end of the drive motor and connected by a key. Fixed to the motor output shaft, the pulley has 2-3 grooves. One end of the drive belt is clamped onto the drive pulley. A driven pulley is fixedly installed in the middle of the filter cartridge. The driven pulley is annularly fixed to the filter cartridge and is fixed to the outer wall of the middle position of the filter cartridge by clamping or welding. The driven pulley is made of the same material as the drive pulley, and its diameter is designed according to the transmission ratio, usually 2-3 times larger than the diameter of the drive pulley to reduce the rotational speed of the filter cartridge. The other end of the drive belt is clamped onto the driven pulley. A B-type or C-type V-belt is used, which has good water resistance and corrosion resistance. The drive belt passes through a rectangular slot on the fixing frame to transmit the motor power to the filter cartridge. The fixing frame has a rectangular slot for the drive belt to pass through. The width of the slot is 5-10 mm greater than the thickness of the drive belt, and the length meets the belt tension adjustment requirements.

[0010] Preferably, the transmission assembly includes a baffle, a waterproof plate, a driving gear ring, a transmission gear, a driven gear, a fixed plate, and a fixed rod. The baffle is fixedly mounted on the limiting frame, the waterproof plate is fixedly mounted on the fixed rod, and the filter cartridge is fixedly mounted with a driving gear ring. The driving gear ring rotates with the rotation of the filter cartridge and has helical or spur teeth machined on its inner ring, with a module of 2-4 and 60-120 teeth. When the filter cartridge rotates, the driving gear ring rotates synchronously, providing a power source. One end of the fixed rod is fixedly mounted on the baffle, and the other end of the fixed rod passes through the waterproof plate and is fixedly mounted on the fixed plate. The fixed plate is fixedly mounted on the feed pipe, and the coverage area of ​​the fixed plate is less than one-third of the cross-sectional area of ​​the feed pipe. The coverage area of ​​the fixed plate is less than one-third of the cross-sectional area of ​​the feed pipe (usually 1 / 4-1 / 3) to ensure that the flow of sewage is not affected. A bearing seat is machined on the fixed plate for mounting the reciprocating lead screw; the transmission gear is rotatably mounted on the fixed rod, and the fixed rod limits the axial movement of the transmission gear; three stainless steel round bars of Φ20-30mm are welded to the baffle plate at one end and to the fixed plate at the other end, with their length extending through the entire interior of the filter cartridge, and are evenly distributed along the circumference; the driven gear is rotatably mounted on the fixed plate; the driving gear ring, the transmission gear, and the driven gear mesh.

[0011] Preferably, the cleaning assembly includes a reciprocating lead screw, a fixed bushing, a guide groove, meshing teeth, a cleaning disc, and a cleaning scraper. One end of the reciprocating lead screw is fixedly mounted on the driven gear, and the other end is fixedly connected to the driven gear via a coupling. The other end is supported on a fixed plate via the fixed bushing. The reciprocating lead screw uses a trapezoidal or rectangular thread with a pitch of 10-20 mm, and its length is consistent with the effective length of the filter cartridge (1500-3000 mm). The rod body surface is milled with two guide grooves of opposite directions, each groove being 5-8 mm wide and 3-5 mm deep. The two guide grooves are connected at both ends by an arc transition, forming a closed loop. A fixed bushing is rotatably mounted on the other end of the reciprocating screw. The fixed bushing is welded to a fixed plate and has a copper alloy or polytetrafluoroethylene bearing embedded inside to provide support for the reciprocating screw and reduce friction. The fixed bushing is fixedly mounted on the fixed plate. The reciprocating screw has staggered guide grooves, and the length of the guide groove on the reciprocating screw is the same as the length of the filter cartridge at its maximum diameter. The guide grooves have meshing teeth, and a cleaning disc is fixedly mounted on the meshing teeth. The cleaning disc has an array of limit holes, and the fixed rod passes through the limit holes to limit the cleaning disc. A cleaning scraper is mounted on the cleaning disc.

[0012] Preferably, the cleaning disc has a rectangular cavity, a movable block is fixedly installed inside the rectangular cavity, a rotating column is fixedly installed on the top of the meshing teeth, a limit groove is formed on the movable block, and the rotating column is rotatably installed on the limit groove; when the meshing teeth move to the end position along the guide groove, the meshing teeth and the rotating column rotate under the guidance of the guide groove, thereby changing the direction of the meshing teeth and causing the meshing teeth to drive the movable block and the cleaning disc to move in the opposite direction; except for the rectangular cavity, the cleaning disc has an array of water permeable holes, and a one-way valve is fixedly installed in the water permeable holes, the flow direction of the one-way valve is from the side of the cleaning disc closest to the water inlet pipe to the other side.

[0013] Preferably, a hinge rod is fixedly installed on the cleaning disc, and a hinge sleeve is fixedly installed on the cleaning scraper; a limiting protrusion is provided on one side of the cleaning disc, the limiting protrusion limits the rotation of one side of the cleaning scraper, and the end of the cleaning scraper is made of deformable rubber material.

[0014] Preferably, a collection bucket is fixedly installed on one side of the filter cartridge, and the collection bucket rotates with the rotation of the filter cartridge. The collection bucket has an outlet, and a stop block is movably installed on the outlet. A scraper is fixedly installed on the fixed rod. The scraper is fixed so that the dirt adhering to the inner wall of the collection bucket can be cleaned by the relative movement between the movable collection bucket and the scraper.

[0015] Preferably, the backwashing device includes an overflow trough, a filter box, a filter plate, a water guide pipe, a pressurized water pump, a water supply pipe, a support frame, and a high-pressure nozzle. The overflow trough is located on one side of the box body. The filter box is fixedly installed on the box body and communicates with the box body through the overflow trough. A filter plate is fixedly installed inside the filter box. One end of the water guide pipe is fixedly installed on the top of the filter box. The other end of the water guide pipe is fixedly installed at the inlet of the pressurized water pump. The pressurized water pump is fixedly installed on the box body. A water supply pipe is fixedly connected to the outlet of the pressurized water pump. The array of water supply pipes is fixedly installed on the box body, and a high-pressure nozzle is fixedly installed at the end of the water supply pipe. A support frame is provided on the high-pressure nozzle to support it, and the support frame is fixedly installed inside the box body.

[0016] A wastewater treatment method for water pollution control, the method is as follows: S1: Introduce the wastewater to be treated into the tank inlet, controlling the influent flow rate to be 5-10 m³ / h, with influent turbidity <200 NTU and COD <500 mg / L; the wastewater first enters the primary filtration device, which has a built-in 50-100 μm stainless steel filter screen. Under the action of gravity, the primary filtration is completed, removing suspended solids and impurities with a particle size >100 μm. The primary filtration time is controlled at 3-5 minutes, and the turbidity of the primary filtration effluent is reduced to <50 NTU; S2: The pre-filtered water enters the filter cartridge of the microfiltration device through the feed pipe. The drive motor of the drive assembly is started and the speed is set to 30-60 r / min. The drive pulley and drive belt drive the driven pulley, so that the filter cartridge rotates continuously and uniformly on the limit frame. The wastewater is filtered by cross-flow through the built-in microfiltration membrane (polyvinylidene fluoride or polyethersulfone material) with a pore size of 0.1-0.5μm inside the filter cartridge. The operating pressure is controlled at 0.05-0.15MPa and the membrane flux is maintained at 60-120L / (m²·h). The filtrate flows through the membrane wall into the product water area at the bottom of the tank and enters the collection tank through the overflow tank. The turbidity of the product water is <0.2NTU and SS is <5mg / L. S3: During the rotation of the filter cartridge, the transmission components start synchronously: the active gear ring fixed to the inner wall of the filter cartridge rotates with the filter cartridge, driving the transmission gear to rotate. The transmission gear meshes with the driven gear, driving the reciprocating screw to rotate at a speed of 10-20 r / min; the cleaning disc, through the meshing teeth and the guide groove of the reciprocating screw, moves reciprocally along the axial direction of the filter cartridge at a speed of 0.05-0.1 m / s under the limiting action of the fixed rod, with a travel distance equal to the effective length of the filter cartridge (1.5-2.0 m); the cleaning scraper... Under the action of the limiting protrusion, the filter cake layer attached to the inner wall of the membrane is scraped off by the rubber material at its end with a contact pressure of 0.5-1.0 kPa when moving towards the water outlet pipe. When moving towards the water outlet pipe, the cleaning scraper rotates inward along the hinge rod under the push of the water flow. At this time, the rubber material at the end of the cleaning scraper does not contact the inner wall of the membrane. The detached pollutants enter the collection bucket at the end of the filter cartridge under the push of the cleaning disc. The reciprocating cleaning cycle is synchronized with the rotation cycle of the filter cartridge. Each reciprocating motion takes 2-3 minutes to complete. S4: When the filter cartridge reaches the preset cycle (2 hours of continuous operation or the transmembrane pressure difference rises to 0.18MPa), the backwashing program is automatically started: the permeate in the collection tank enters the filter box through the overflow trough, and after secondary filtration through the filter plate (50μm), it is delivered by the pressurized water pump at a pressure of 0.3-0.5MPa to the high-pressure nozzle, with a spray angle of 120° and a flow rate of 5-10m / s, to perform pulse-type rinsing on the outer wall of the filter cartridge, with each rinsing lasting 30-60s; the backwashing frequency is set to once every 2 hours, or automatically adjusted according to the feedback from the online turbidity meter; S5: The collection bucket rotates synchronously with the filter cartridge. The concentrated sludge adhering to its inner wall is continuously scraped off by the scraper on the fixed rod. The gap between the scraper and the inner wall of the collection bucket is maintained at 1-2 mm. When the sludge concentration in the collection bucket reaches 3-5% (solid content) or after 8 hours of operation, the staff opens the outlet baffle to collect the sludge inside and prevent sludge accumulation. S6: Throughout the entire treatment process, the PLC control system monitors the inlet water pressure, product water flow rate, transmembrane pressure difference, filter cartridge speed, and cleaning disc position in real time. When the product water turbidity > 0.5 NTU or TMP > 0.2 MPa, the system automatically alarms and extends the backwashing time to 90 seconds; when TMP > 0.25 MPa or the filtration flux decreases by > 20%, the system triggers a shutdown protection and starts a chemical cleaning program (1% citric acid circulating cleaning for 30 minutes); finally, the product water stays in the collection tank for > 30 minutes, and after testing for COD < 50 mg / L, ammonia nitrogen < 5 mg / L, and total phosphorus < 0.5 mg / L, it meets the standards for discharge or reuse.

[0017] The beneficial effects of this invention are as follows: 1. This invention utilizes the linkage design of the rotating filter cartridge and the built-in transmission-cleaning assembly of the microfiltration device. The filter cartridge's rotational power drives the reciprocating screw to rotate via the active gear ring, transmission gear, and driven gear. This causes the meshing teeth to slide within the interlaced guide grooves, driving the cleaning disc to reciprocate along the fixed rod. This precisely converts the filter cartridge's rotational motion into the axial mechanical scraping action of the cleaning scraper, achieving continuous online cleaning of the microfiltration membrane's inner wall during filtration. Simultaneously, a one-way limiting mechanism formed by the hinge rod, hinge sleeve, and limiting protrusion ensures that when the cleaning disc moves towards the drive assembly, the wastewater pressure pushes the scraper. At the limiting protrusion, the deformable rubber strip at the end scrapes off the filter cake layer with a pressure of 0.5-1.0 kPa. When moving in the reverse direction, the water flow pushes the scraper to rotate inward and detach from the membrane wall, avoiding backflow of pollutants. This achieves the dual functions of unidirectional high-efficiency scraping and sewage flow. This structure works in conjunction with the overflow tank, filter plate, pressurized water pump, and high-pressure nozzle of the external backwashing device to form a bidirectional cleaning mechanism, which makes the transmembrane pressure difference recovery rate >90%, extends the cleaning cycle to 2-4 hours, and reduces the frequency of chemical cleaning by 60-70%. This significantly extends the service life of the microfiltration membrane and improves the stability of continuous system operation.

[0018] 2. This invention utilizes a drive motor-drive pulley-driven pulley belt transmission structure in the drive assembly to precisely control the filter cartridge speed within the range of 30-60 r / min, providing a stable power source for the internal cleaning assembly. The transmission assembly employs a support system consisting of a baffle-waterproof plate-fixed rod-fixed plate, integrating the active gear ring, transmission gear, and driven gear inside the filter cartridge. Utilizing the filter cartridge's rotation as the sole power source, it eliminates the need for additional drive devices, achieving zero-cost power conversion and 100% internal transmission. Simultaneously, the fixed plate covers an area less than one-third the cross-sectional area of ​​the feed pipe. Combined with the array of permeable holes and one-way valve structure on the cleaning disc, this ensures a wastewater flow area >60%, minimizing the structural impact on filtration throughput.

[0019] 3. The treatment method of this invention uses a PLC control system to monitor the transmembrane pressure difference, permeate turbidity, filter cartridge speed, and cleaning disc position in real time. When TMP > 0.18MPa or the system has been running for 2 hours, a backwashing program is automatically triggered. The permeate water itself is used to perform a 30-60s pulse flush on the outer wall of the filter cartridge through the overflow tank, filter box, pressurized water pump, and high-pressure nozzle. The flushing water consumption is only 5-8% of the permeate water volume. When the sludge concentration in the collection tank reaches 3-5% or the system has been running for 8 hours, the operator is reminded to open the outlet baffle. The scraper continuously scrapes the wall to achieve sludge discharge without clogging. When TMP > 0.25MPa or the flux decreases by > 20%, a shutdown protection and chemical cleaning program are triggered. This intelligent closed-loop control enables the device to achieve a fault response time of < 5s, reduce manual maintenance costs by 80%, and achieve a stable compliance rate of > 98% for effluent COD < 50mg / L, ammonia nitrogen < 5mg / L, and total phosphorus < 0.5mg / L. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is an overall schematic diagram of the present invention; Figure 2 This is a side view of the present invention; Figure 3 This is a schematic diagram of the microfiltration device and backwashing assembly of the present invention; Figure 4 This is a schematic diagram of the filter cartridge and its internal structure according to the present invention; Figure 5 This is a schematic cross-sectional view of the filter cartridge of the present invention; Figure 6 This is a schematic diagram of the drive assembly and transmission assembly of the present invention; Figure 7 This is a schematic diagram of the installation position of the waterproof membrane of the present invention; Figure 8 This is a schematic diagram of the cleaning disk of the present invention; Figure 9 This is a schematic diagram of the installation position of the limiting groove of the present invention; Figure 10 This is a schematic diagram of the installation position of the hinge rod of the present invention; Figure 11 This is a schematic diagram of the cleaning scraper of the present invention; Figure 12 This is a flowchart of the method of the present invention.

[0022] In the diagram: 1. Housing; 2. Pre-filtration device; 3. Microfiltration device; 31. Feed pipe; 32. Limiting frame; 33. Filter cartridge; 331. Collection bucket; 332. Discharge port; 333. Stop block; 334. Scraper; 34. Drive assembly; 341. Fixing frame; 342. Rectangular through slot; 343. Drive motor; 344. Drive pulley; 345. Driven pulley; 346. Drive belt; 35. Transmission assembly; 351. Baffle; 352. Waterproof plate; 353. Drive gear ring; 354. Transmission gear; 355. Driven gear; 356. Fixing plate; 357. Fixing rod; 36. Cleaning assembly 361. Reciprocating lead screw; 362. Fixed bushing; 363. Guide groove; 364. Meshing teeth; 365. Cleaning disc; 3651. Rectangular cavity; 3652. Moving block; 3653. Rotating column; 3654. Limiting groove; 3655. Water permeable hole; 3656. One-way valve; 3657. Hinge rod; 3658. Hinge sleeve; 3659. Limiting protrusion; 366. Cleaning scraper; 4. Backwashing device; 41. Overflow trough; 42. Filter box; 43. Filter plate; 44. Water guide pipe; 45. Pressurized water pump; 46. Water delivery pipe; 47. Support frame; 48. High-pressure nozzle; 5. Collection box. Detailed Implementation

[0023] like Figures 1 to 12 As shown, a wastewater treatment device for water pollution control includes a housing 1, a primary filter 2, a microfiltration device 3, a backwashing device 4, and a collection tank 5. The primary filter 2, used for preliminary filtration of wastewater, is fixedly installed on one side of the housing 1. The microfiltration device 3 is installed on one side of the primary filter 2. The microfiltration device 3 is used to filter wastewater through a reverse osmosis membrane while periodically cleaning its interior. The backwashing assembly is fixedly installed on one side of the housing 1. The backwashing assembly uses the water filtered by the microfiltration device 3 to rinse the exterior of the microfiltration device 3. The collection tank 5, used to collect the treated water, is installed on one side of the housing 1. Through the linkage design of the rotating filter cartridge 33 of the microfiltration device 3 and the built-in transmission-cleaning assembly 357, fixed rod, and fixed rod 36, the rotational power of the filter cartridge 33 drives the reciprocating screw 361 to rotate via the active gear ring 353, transmission gear 354, and driven gear 355. This causes the meshing teeth 364 to slide within the interlaced guide groove 363 and drive the cleaning disc 365 to reciprocate along the fixed rod. This precisely converts the rotational motion of the filter cartridge 33 into the axial mechanical scraping action of the cleaning scraper 366, achieving continuous online cleaning of the inner wall of the microfiltration membrane during the filtration process. Simultaneously, the unidirectional limiting mechanism formed by the hinge rod 3657, hinge sleeve 3658, and limiting protrusion 3659 ensures that when the cleaning disc 365 moves towards... When the drive component 34 moves in one direction, the sewage pressure pushes the scraper to the limiting protrusion 3659, and the deformable rubber strip at the end scrapes off the filter cake layer with a pressure of 0.5-1.0 kPa. When it moves in the opposite direction, the water flow pushes the scraper to rotate inward and detach from the membrane wall, avoiding backflow of pollutants. This achieves the dual functions of unidirectional high-efficiency scraping and sewage flow. This structure works in conjunction with the overflow trough 41, filter plate 43, pressurized water pump 45, and high-pressure nozzle 48 of the external backwashing device 4 to form a bidirectional cleaning mechanism, which makes the transmembrane pressure difference recovery rate >90%, extends the cleaning cycle to 2-4 hours, and reduces the frequency of chemical cleaning by 60-70%. This significantly extends the service life of the microfiltration membrane and improves the continuous operation stability of the system.

[0024] like Figures 1 to 11 As shown, the microfiltration device 3 includes a feed pipe 31, a limiting frame 32, a filter cartridge 33, a drive assembly 34, a transmission assembly 35, and a cleaning assembly 357; a fixing rod 36; the feed pipe 31 is fixedly installed on the limiting frame 32 and connected to the primary filtration device 2, and the feed pipe 31 is used to transport the pre-filtered water into the filter cartridge 33; the limiting frame 32 is symmetrically fixedly installed in the housing 1, and the limiting frame 32 is used to limit the filter cartridge 33, so that the filter cartridge 33 can move within the limited space. The filter cartridge 33 rotates on the limiting frame 32 and is rotatably mounted on the limiting frame 32 and connected to the feed pipe 31. The filter cartridge 33 is used to cooperate with the microfiltration membrane to filter sewage. It should be noted that the microfiltration membrane is fixedly mounted on the inner wall of the filter cartridge 33. When the flux is <80% or the membrane is damaged, the microfiltration membrane needs to be replaced. At this time, the machine needs to be stopped and emptied, the limiting frames 32 at both ends of the filter cartridge 33 need to be disassembled, the old membrane needs to be cut off, the support frame needs to be cleaned with alcohol, and the new membrane needs to be put on the frame and fixed by welding with a hot melt gun. The drive assembly 34 is installed in the middle of the filter cartridge 33 and fixed to the top of the housing 1. The drive assembly 34 is used to drive the filter cartridge 33 to rotate. The transmission assembly 35 is installed inside the filter cartridge 33. The transmission assembly 35 is used to drive the cleaning assembly 357 and the fixing rod 36 to move periodically inside the filter cartridge 33 to clean the filter cartridge 33. The cleaning assembly 357 and the fixing rod 36 are installed inside the filter cartridge 33. During operation, the staff introduces the wastewater to be treated into the feed inlet of the tank 1. The wastewater first enters the primary filtration device 2 to complete the initial filtration. The effluent from the primary filtration is transported to the inside of the filter cartridge 33 through the feed pipe 31. The drive motor 343 starts and drives the filter cartridge 33 to rotate. The rotating filter cartridge 33 filters the wastewater through the microfiltration membrane. At the same time, the transmission component 35 drives the cleaning component 357 and the fixing rod 36 to periodically clean the inner wall of the microfiltration membrane inside the filter cartridge 33, thereby preventing pollutants from forming a dense filter cake layer on the inside of the membrane, which would affect the filtration efficiency. Through the coordinated operation of the self-rotating filter cartridge 33 and the built-in transmission-cleaning assembly 357 and fixing rod 36, the rotational power of the filter cartridge 33 drives the cleaning assembly 357 and fixing rod 36 to periodically mechanically scrape the inner wall of the microfiltration membrane during the filtration process. This effectively prevents pollutants from forming a dense filter cake layer on the inner side of the membrane, significantly improves membrane flux stability and filtration efficiency, extends the service life of the microfiltration membrane, reduces the frequency of downtime for cleaning and the consumption of chemical agents, thereby achieving continuous, efficient, low-consumption and stable wastewater treatment.

[0025] like Figures 1 to 6 As shown, the drive assembly 34 includes a fixing frame 341, a rectangular through slot 342, a drive motor 343, a drive pulley 344, a driven pulley 345, and a drive belt 346. The fixing frame 341 is fixedly installed above the housing 1 and is used to fix the drive motor 343. The drive motor 343 is fixedly installed on the fixing frame 341 and is used to drive the drive pulley 344 to rotate. The drive pulley 344 is fixedly installed at the output end of the drive motor 343 and is used to drive the drive belt 346. The driving belt 346 drives the driven pulley 345 to rotate; one end of the driving belt 346 is engaged with the driving pulley 344; the driven pulley 345 is fixedly installed in the middle of the filter cylinder 33; the rotation of the driven pulley 345 drives the filter cylinder 33 to rotate on the limiting frame 32; the driven pulley 345 is fixed to the filter cylinder 33 in a ring shape; the other end of the driving belt 346 is engaged with the driven pulley 345; the fixing frame 341 has a rectangular through groove 342 for the driving belt 346 to pass through; the through groove is used for the driving belt 346 to rotate. During operation, when the pre-filtered water enters the filter cartridge 33 of the microfiltration device 3 through the feed pipe 31, the drive motor 343 starts and drives the drive pulley 344 to rotate. The rotating drive pulley 344 drives the drive belt 346 to rotate in the rectangular through groove 342, which in turn drives the driven pulley 345 to rotate. The driven pulley 345 drives the filter cartridge 33 to rotate on the limit frame 32, thereby achieving the filtration of sewage. The aforementioned drive assembly 34 uses a belt drive to transmit power from the drive motor 343 to the driven pulley 345, which is fixed in the middle of the filter cartridge 33. The through-slot design on the fixing frame 341 achieves a reasonable layout of the transmission path. This not only makes the structure simple and compact and easy to install and maintain, but also ensures smooth transmission and low noise. It also allows for flexible adjustment of the speed of the filter cartridge 33 by changing the pulley, effectively improving the operational reliability of the device and its adaptability to different working conditions.

[0026] like Figures 4 to 7 As shown, the transmission assembly 35 includes a baffle 351, a waterproof plate 352, a driving gear ring 353, a transmission gear 354, a driven gear 355, a fixed plate 356, and a fixed rod. The baffle 351 is fixedly installed on the limiting frame 32 and is used to seal one side of the filter cartridge 33. The waterproof plate 352 is fixedly installed on the fixed rod and is used to protect the gear set. The driving gear ring 353 is fixedly installed on the filter cartridge 33 and rotates with the rotation of the filter cartridge 33. The driving gear ring 353 is used to drive the transmission gear 354 to rotate. One end of the fixed rod is fixedly installed on the baffle 351, and the other end of the fixed rod passes through the waterproof plate 352 and is fixedly installed on the fixed plate 356. The rod is used to limit the transmission gear 354, allowing it to rotate only around the fixed rod; the fixed plate 356 is fixedly installed on the feed pipe 31, and the coverage area of ​​the fixed plate 356 is less than one-third of the cross-sectional area of ​​the feed pipe 31, thereby minimizing the impact of the fixed plate 356 on the water inlet pipe; the transmission gear 354 is rotatably installed on the fixed rod, and the fixed rod limits the axial movement of the transmission gear 354; the transmission gear 354 rotates and the driven gear 355 rotates; the driven gear 355 is rotatably installed on the fixed plate 356; the driving gear ring 353, the transmission gear 354, and the driven gear 355 mesh, and the driven gear 355 rotates to drive the cleaning assembly 357; the fixed rod 36 reciprocates within the filter cartridge 33 to complete the cleaning of the filter cartridge 33; Regarding the above design, it is important to emphasize that during installation, the baffle 351 is first fixedly installed on the limiting frame 32. The baffle 351 has a positioning block at the installation position of the transmission gear 354, which only provides initial positioning for the transmission gear 354. Then, the filter cartridge 33 is inserted into the baffle 351. At this time, the driving gear ring 353 meshes with the transmission gear 354 on the baffle 351. Simultaneously, an annular sleeve integrated with the brake gear ring is also provided inside the filter cartridge 33. The height of the annular sleeve is higher than that of the driving gear ring 353, and it rotates together with the filter cartridge 33. At this time, both the transmission gear 354 and the driven gear 355 are inside the annular sleeve. Then, the feed pipe... 31 drives the fixing plate 356 and the fixing rod to be inserted into the filter cylinder 33, so that the fixing rod is inserted into the positioning block. The fixing rod and the positioning block are engaged in a snap-fit ​​manner (such as the snap-fit ​​of a protrusion and a groove). When the fixing rod and the positioning block are engaged, the waterproof plate 352 fixed on the fixing rod is in contact with the annular sleeve, thereby forming a preliminary sealing environment between the annular sleeve and the waterproof plate 352 to protect the transmission component 35. When the filter cylinder 33 rotates, the active gear ring 353 and the annular sleeve rotate, while the waterproof plate 352 remains stationary. The above design only provides preliminary waterproofing for the transmission component 35. The entire design of the transmission component 35 needs to use waterproof materials. During operation, the filter cartridge 33 drives the active gear ring 353 to rotate, the rotating gear ring drives the transmission gear 354 to rotate, the rotating transmission gear 354 drives the driven gear 355 to rotate, and the driven gear 355 drives the cleaning component 357 and the fixed rod 36 to move periodically within the filter cartridge 33. The aforementioned transmission component 35 adopts a built-in gear transmission structure, cleverly utilizing the rotation of the filter cartridge 33 as a power source. The gear set is double-sealed and protected by the baffle 351 and the waterproof plate 352. The axial limit of the transmission gear 354 by the fixed rod ensures transmission stability. The small-area design of the fixed plate 356 minimizes the impact on the incoming water, realizing the precise conversion of the rotational motion of the filter cartridge 33 to the reciprocating linear motion of the cleaning component 357 and the fixed rod 36. This not only eliminates the need for an additional drive device, saving energy and reducing consumption, but also ensures smooth and reliable transmission, compact structure, and resistance to sewage erosion, effectively guaranteeing the stability of the periodic movement of the cleaning component 357 and the fixed rod 36 and the long-term efficient operation of the device.

[0027] like Figures 1 to 11As shown, the cleaning assembly 357 and the fixed rod 36 include a reciprocating screw 361, a fixed bushing 362, a guide groove 363, meshing teeth 364, a cleaning disc 365, and a cleaning scraper 366. One end of the reciprocating screw 361 is fixedly mounted on the driven gear 355, and the reciprocating screw 361 is used to drive the cleaning disc 365 to reciprocate within the filter cartridge 33. The other end of the reciprocating screw 361 is rotatably mounted with the fixed bushing 362, which is used to limit the movement of the reciprocating screw 361. The fixed bushing 362 is fixedly mounted on the fixed plate 356. The reciprocating screw 361 is provided with staggered guide grooves 363, which are used to engage the meshing teeth 364. The movement is guided by the guide groove 363 located on the reciprocating screw 361; the length of the guide groove 363 is the same as the length of the maximum diameter part of the filter cartridge 33; the guide groove 363 is engaged with meshing teeth 364, which are used to slide in the guide groove 363 and drive the cleaning disc 365 to reciprocate on the fixed rod; the cleaning disc 365 is fixedly installed on the meshing teeth 364, and the cleaning disc 365 is used to drive the cleaning scraper 366 to reciprocate; the cleaning disc 365 is provided with an array of limit holes, and the fixed rod passes through the limit holes to limit the cleaning disc 365; the cleaning disc 365 is equipped with a cleaning scraper 366, which is used to reciprocate and thus clean the surface of the microfiltration membrane fixed inside the filter cartridge 33. During operation, the driven gear 355 rotates, driving the reciprocating screw 361 to rotate under the support of the fixed bushing 362. The staggered guide grooves 363 rotate accordingly, and the meshing teeth 364 slide in the guide grooves 363, driving the cleaning disc 365 to move back and forth along the fixed rod. The fixed rod passes through the limiting hole of the cleaning disc 365 to ensure its linear movement. The cleaning scraper 366 on the cleaning disc 365 scrapes and cleans the microfiltration membrane on the inner wall of the filter cartridge 33 with a pressure of 0.5-1.0 kPa. The scraped-off contaminants pass through the water permeable holes 3655 of the cleaning disc 365 and enter the end of the filter cartridge 33. When the meshing teeth 364 move to the end of the guide groove 363, they automatically reverse direction under the forced guidance of the staggered guide grooves 363, driving the cleaning disc 365 to move in the opposite direction. At this time, the cleaning scraper 366 is pushed by the water flow and rotates inward along the hinge rod 3657 to disengage from the membrane wall, avoiding pushing the contaminants back. After completing one reciprocating cleaning cycle, the next cycle begins. The aforementioned cleaning components 357, fixing rod, and 36 employ a transmission structure of reciprocating screw 361 and staggered guide groove 363. Through the sliding engagement of meshing teeth 364 and guide groove 363, and the limiting and guiding of cleaning disc 365 by the fixing rod, precise reciprocating linear motion of cleaning disc 365 within filter cartridge 33 is achieved. This drives cleaning scraper 366 to perform unidirectional scraping and cleaning of the inner wall of the microfiltration membrane with constant pressure, avoiding the problem of incomplete removal of deep contaminants by traditional rinsing methods. Simultaneously, the forced reversing design at the end of guide groove 363 enables cleaning disc 365 to automatically move in the opposite direction. Combined with the internal rotation avoidance mechanism of scraper under the action of water flow, contaminants are effectively prevented from being pushed back. This achieves a synergistic effect of online continuous cleaning and efficient sewage discharge, significantly extending the cleaning cycle and service life of the microfiltration membrane, and greatly improving the operational stability and filtration efficiency of the device.

[0028] like Figures 8 to 11 As shown, the cleaning disc 365 has a rectangular cavity 3651 for placing a movable block 3652. The movable block 3652 is fixedly installed inside the rectangular cavity 3651. A rotating column 3653 is fixedly installed on the top of the meshing teeth 364. A limiting groove 3654 is formed on the movable block 3652, and the rotating column 3653 is rotatably mounted on the limiting groove 3654. When the meshing teeth 364 move to the end position along the guide groove 363, the meshing teeth 364 and the rotating column 3652 are guided by the guide groove 363. 3. Rotation changes the direction of the meshing teeth 364, causing the meshing teeth 364 to drive the moving block 3652 and the cleaning disc 365 to move in opposite directions. The cleaning disc 365 has water-permeable holes 3655 arranged in an array except for the rectangular cavity 3651. The water-permeable holes 3655 are used to allow sewage to continue flowing into the filter cartridge 33 through the one-way valve 3656 when the cleaning disc 365 moves towards the water inlet pipe. The one-way valve 3656 is fixedly installed in the water-permeable hole 3655. The flow direction of the one-way valve 3656 is from the side of the cleaning disc 365 closest to the water inlet pipe to the other side. By setting a rectangular cavity 3651 on the cleaning disc 365 and installing a moving block 3652, the rotating column 3653 at the top of the meshing teeth 364 forms a rotational engagement with the limiting groove 3654 on the moving block 3652. When the meshing teeth 364 move to the end of the guide groove 363, the rotating column 3653 is automatically turned by the forced guidance of the guide groove 363, thereby driving the cleaning disc 365 to change direction precisely. No additional reversing drive element is required, resulting in a compact structure and high reliability. At the same time, a one-way valve 3656 is installed in the water permeable hole 3655 of the cleaning disc 365, so that the sewage can only flow unidirectionally from the feed side to the discharge side of the cleaning disc 365. This ensures the continuity of sewage flow during the reciprocating movement of the cleaning disc 365 and effectively prevents the backflow of scraped pollutants. It realizes the non-interference synchronous operation of the mechanical cleaning and filtration processes, significantly improving the system's operational stability, cleaning efficiency, and continuous maintenance of filtration flux.

[0029] like Figures 8 to 11 As shown, a hinge rod 3657 is fixedly installed on the cleaning disc 365, and a hinge sleeve 3658 is fixedly installed on the cleaning scraper 366; the hinge sleeve 3658 rotates on the hinge rod 3657; a limiting protrusion 3659 is provided on one side of the cleaning disc 365, which is used to limit the cleaning scraper 366; the limiting protrusion 3659 limits the rotation of one side of the cleaning scraper 366, and the end of the cleaning scraper 366 is made of deformable rubber material; when the cleaning disc 365 moves along the feed pipe 31 towards the drive assembly 34, at this time, because there is sewage inside the filter cartridge 33... At this time, the sewage will exert pressure on the cleaning scraper 366, causing it to rotate. Due to the limiting action of the limiting protrusion 3659, when the cleaning scraper 366 contacts the microfiltration membrane on the inner wall of the filter cartridge 33, the limiting protrusion 3659 is locked and fixed to the cleaning disc 365, allowing the inner wall of the microfiltration membrane to be cleaned. When the cleaning disc 365 moves along the drive assembly 34 towards the feed pipe 31, the water flow is reversed, thus driving the cleaning scraper 366 to rotate. At this time, the cleaning scraper 366 does not contact the inner wall of the microfiltration membrane, and the gap between the cleaning disc 365 and the cleaning scraper 366 allows sewage to flow. The rotating connection structure between the hinge rod 3657 and the hinge sleeve 3658 enables the cleaning scraper 366 to have adaptive swing capability, and works with the limiting protrusion 3659 to form a one-way mechanical limit. It cleverly uses the sewage flow pressure as a power source to realize the automatic switching of the scraper's working state: when the cleaning disc 365 moves towards the drive component 34, the water flow pressure pushes the scraper to rotate to the limiting protrusion 3659, and the deformable rubber material at the end can make appropriate pressure contact with the inner wall of the microfiltration membrane for efficient scraping; when moving in the opposite direction, the water flow pushes the scraper away from the membrane wall to form a flow gap, which not only avoids pushing the newly filtered pollutants on the microfiltration membrane back, but also ensures smooth sewage flow. The one-way cleaning function can be completed without additional drive components. The structure is simple, reliable, and responsive, which significantly improves the cleaning efficiency and membrane surface protection effect.

[0030] like Figures 1 to 2 As shown, a collection bucket 331 is fixedly installed on one side of the filter cartridge 33. The collection bucket 331 rotates with the rotation of the filter cartridge 33. The collection bucket 331 has a discharge port 332, and a stop block 333 is movably installed on the discharge port 332. A scraper 334 is fixedly installed on the fixed rod. The scraper 334 is fixed so that the dirt attached to the inner wall of the collection bucket 331 can be cleaned by the relative movement between the movable collection bucket 331 and the scraper 334. By integrally setting a rotatable collection bucket 331 at the end of the filter cartridge 33 and installing a scraper 334 on a fixed rod, the relative movement between the collection bucket 331 and the scraper 334 generated when the collection bucket 331 rotates with the filter cartridge 33 is cleverly utilized to automatically scrape off the concentrated sludge attached to the inner wall of the bucket. This effectively prevents the sludge from hardening and accumulating in the collection bucket 331, avoids the problems of clogging the discharge port 332 and reducing the effective volume, and realizes the synchronous and continuous operation of sludge collection and bucket wall cleaning.

[0031] like Figures 4 to 7As shown, the backwashing device 4 includes an overflow trough 41, a filter box 42, a filter plate 43, a water guide pipe 44, a pressurized water pump 45, a water delivery pipe 46, a support frame 47, and a high-pressure nozzle 48. The overflow trough 41 is located on one side of the housing 1 and is used to transport the filtered water flow into the filter box 42. The filter box 42 is fixedly installed on the housing 1 and is connected to the housing 1 through the overflow trough 41. The filter box 42 is used to fix the filter plate 43. The filter plate 43 is fixedly installed inside the filter box 42 and is used to further filter the water flow. One end of the water guide pipe 44 is fixedly installed on the top of the filter box 42. The water guide pipe 44 is used to transport the filter box 42... The system includes a liquid pumping filter box 42; the other end of the water guide pipe 44 is fixedly installed at the inlet of the pressurized water pump 45, which is fixedly installed on the box body 1 and is used to transport water to the water delivery pipe 46; the outlet of the pressurized water pump 45 is fixedly connected to the water delivery pipe 46, which is used to transport water to the high-pressure nozzle 48; the array of water delivery pipes 46 is fixedly installed on the box body 1, and the high-pressure nozzle 48 is fixedly installed at the end of the water delivery pipes 46; the high-pressure nozzle 48 is provided with a support frame 47 for supporting it, and the support frame 47 is fixedly installed inside the box body 1; the high-pressure nozzle 48 is used to backwash the filter cartridge 33. During operation, the filtered product water flows naturally into the filter box 42 through the overflow trough 41 on one side of the box 1. The filter plate 43 in the filter box 42 performs secondary fine filtration on the product water to remove small particles. Then, the water guide pipe 44 delivers the finely filtered water to the pressurized water pump 45. After the pressurized water pump 45 starts, it generates a pressure water flow of 0.3-0.5MPa and pumps it into the water delivery pipe 46. The water delivery pipe 46 distributes the high-pressure water flow to each high-pressure nozzle 48 through an array arrangement. The high-pressure nozzles 48 are fixed by the support frame 47 and perform pulse backwashing on the outer wall of the filter cartridge 33. The support frame 47 ensures that the spray angle of the high-pressure nozzles 48 remains stable during the backwashing process. The entire backwashing process does not require manual operation by the operator and is automatically triggered by the PLC based on the transmembrane pressure difference or running time. The backwashing device 4 uses an overflow trough 41 to collect the produced water by self-overflow. After secondary filtration through the filter plate 43, a high-pressure water flow of 0.3-0.5MPa is generated by the pressurized water pump 45. The water is then distributed to each high-pressure nozzle 48 through the water supply pipe 46 array. The support frame 47 ensures that the nozzle spray angle is stable. The entire backwashing process is automatically triggered and executed by the PLC without manual intervention. This design not only achieves uniform and efficient rinsing of the outer wall of the filter cartridge 33, but also utilizes the device's own produced water as the rinsing water source, eliminating the need for an external cleaning water system. It has a compact structure, a high degree of automation, effectively extends the backwashing cycle, and reduces operation and maintenance.

[0032] like Figure 12 As shown, a wastewater treatment method for water pollution control is as follows: S1: The wastewater to be treated is introduced into the feed inlet of tank 1, and the influent flow rate is controlled at 5-10 m³ / h. The turbidity of the influent is <200 NTU and the COD is <500 mg / L. The wastewater first enters the primary filter device 2, which has a built-in 50-100 μm stainless steel filter screen. Under the action of gravity, the primary filtration is completed to remove suspended solids and impurities with a particle size >100 μm. The primary filtration time is controlled at 3-5 min, and the turbidity of the primary filtration effluent is reduced to <50 NTU. S2: The pre-filtered water enters the filter cartridge 33 of the microfiltration device 3 through the feed pipe 31. The drive motor 343 of the drive assembly 34 is started and the speed is set to 30-60 r / min. The driven pulley 345 is driven by the drive pulley 344 and the drive belt 346, so that the filter cartridge 33 rotates continuously and uniformly on the limit frame 32. The wastewater is filtered by cross-flow through the built-in microfiltration membrane (polyvinylidene fluoride or polyethersulfone material) with a pore size of 0.1-0.5μm in the filter cartridge 33. The operating pressure is controlled at 0.05-0.15MPa and the membrane flux is maintained at 60-120L / (m²·h). The filtrate flows through the membrane wall into the product water area at the bottom of the tank 1 and enters the collection tank 5 through the overflow trough 41. The turbidity of the product water is <0.2NTU and SS is <5mg / L. S3: During the rotation of the filter cartridge 33, the transmission assembly 35 starts synchronously: the active gear ring 353 fixed on the inner wall of the filter cartridge 33 rotates with the filter cartridge 33, driving the transmission gear 354 to rotate. The transmission gear 354 meshes with the driven gear 355, driving the reciprocating screw 361 to rotate at a speed of 10-20 r / min. The cleaning disc 365 cooperates with the guide groove 363 of the reciprocating screw 361 through the meshing teeth 364. Under the limiting action of the fixed rod, it reciprocates along the axial direction of the filter cartridge 33 at a speed of 0.05-0.1 m / s. The travel distance is equal to the effective length of the filter cartridge 33 (1.5-2.0 m). Under the action of the limiting protrusion 3659, the cleaning scraper 366 maintains a unidirectional tilt angle. That is, when it moves towards the transmission component 35, the rubber material at its end scrapes off the filter cake layer attached to the inner wall of the membrane with a contact pressure of 0.5-1.0 kPa. When it moves towards the outlet pipe, the cleaning scraper 366 rotates inward along the hinge rod 3657 under the push of the water flow. At this time, the rubber material at the end of the cleaning scraper 366 does not contact the inner wall of the membrane. The detached pollutants enter the collection bucket 331 at the end of the filter cartridge 33 under the push of the cleaning disc 365. The reciprocating cleaning cycle is synchronized with the rotation cycle of the filter cartridge 33, and each reciprocating motion takes 2-3 minutes to complete. S4: When the filter cartridge 33 reaches the preset cycle (2 hours of continuous operation or the transmembrane pressure difference rises to 0.18 MPa), the backwashing program is automatically started: the product water in the collection tank 5 enters the filter box 42 through the overflow tank 41, and after secondary filtration through the filter plate 43 (50 μm), it is delivered by the pressurized water pump 45 at a pressure of 0.3-0.5 MPa to the high-pressure nozzle 48, with a spray angle of 120° and a flow rate of 5-10 m / s, to perform pulse-type rinsing on the outer wall of the filter cartridge 33, with each rinsing lasting 30-60 seconds; the backwashing frequency is set to once every 2 hours, or automatically adjusted according to the feedback from the online turbidity meter; S5: The collection tank 331 rotates synchronously with the filter cartridge 33. The concentrated sludge adhering to its inner wall is continuously scraped off by the scraper 334 on the fixed rod. The gap between the scraper 334 and the inner wall of the collection tank 331 is maintained at 1-2 mm. When the sludge concentration in the collection tank 331 reaches 3-5% (solid content) or when it has been running for 8 hours, the operator opens the baffle 333 of the discharge port 332 to collect the sludge inside and prevent sludge accumulation. S6: Throughout the entire treatment process, the PLC control system monitors the inlet water pressure, product water flow rate, transmembrane pressure difference, filter cartridge speed (33), and cleaning disc position (365) in real time. When the product water turbidity > 0.5 NTU or TMP > 0.2 MPa, the system automatically alarms and extends the backwashing time to 90 seconds; when TMP > 0.25 MPa or the filtration flux decreases by > 20%, the system triggers a shutdown protection and starts a chemical cleaning program (1% citric acid circulating cleaning for 30 minutes); finally, the product water stays in the collection tank (5) for > 30 minutes, and after testing for COD < 50 mg / L, ammonia nitrogen < 5 mg / L, and total phosphorus < 0.5 mg / L, it meets the standards for discharge or reuse.

[0033] The overall working process is as follows: After the staff starts the device, the wastewater to be treated is introduced into the feed port of the tank 1 at a flow rate of 5-10 m³ / h. The wastewater first enters the primary filtration device 2 with a built-in 50-100 μm stainless steel filter screen. Under the action of gravity, the primary filtration is completed in 3-5 minutes, removing suspended solids and impurities with a particle size >100 μm, so that the turbidity of the effluent is reduced to <50 NTU. The pre-filtered water is conveyed to the inside of the filter cartridge 33 through the feed pipe 31. At this time, the drive motor 343 starts and drives the driven pulley 345, which is fixed in the middle of the filter cartridge 33, through the drive pulley 344 and the drive belt 346. This causes the filter cartridge 33 to rotate continuously and uniformly at a speed of 30-60 r / min on the limit frame 32. While the filter cartridge 33 is rotating, the built-in transmission component 35 starts synchronously: the active gear ring 353, which is fixed on the inner wall of the filter cartridge 33, rotates with the filter cartridge 33, driving the transmission gear 354, which is rotatably mounted on the fixed rod, to rotate. This, in turn, drives the driven gear 355 to rotate. The rotation of the driven gear 355 drives the reciprocating screw 361 to rotate at a speed of 10-20 r / min under the support of the fixed bushing 362. The meshing teeth 364 slide in the guide grooves 363 that are staggered in the reciprocating screw 361, causing the cleaning disc 365 to move back and forth along the fixed rod at a speed of 0.05-0.1 m / s. When the cleaning disc 365 moves toward the transmission box, the cleaning scraper 366 maintains a unidirectional tilt angle under the action of the limiting protrusion 3659 and the sewage pressure. The deformable rubber strip at the end scrapes off the filter cake layer attached to the inner wall of the microfiltration membrane with a pressure of 0.5-1.0 kPa. The scraped-off pollutants pass through the one-way valve 3656 in the water permeation hole 3655 of the cleaning disc 365 and enter the end of the filter cartridge 33. When the cleaning disc 365 moves in the opposite direction, the water flow pushes the cleaning scraper 366 to rotate inward along the hinge rod 3657 and detach it from the membrane wall, avoiding pushing the pollutants back. The entire reciprocating cleaning cycle is synchronized with the rotation cycle of the filter cartridge 33, and is completed once every 2-3 minutes to continuously keep the membrane surface clean. When the system reaches the preset cycle (2 hours of continuous operation or the transmembrane pressure difference rises to 0.18MPa), the PLC automatically triggers the backwashing program: the permeate flows naturally into the filter box 42 through the overflow tank 41, and after the fine particles are removed by the secondary fine filtration through the filter plate 43, it is pumped to the water supply pipe 46 by the pressurized water pump 45 at a pressure of 0.3-0.5MPa. The high-pressure nozzles 48 arranged in an array spray at a 120° spray angle and a flow rate of 5-10m / s to perform a 30-60s pulse flush on the outer wall of the filter cartridge 33. The collection bucket 331 rotates synchronously with the filter cartridge 33, and the concentrated sludge attached to its inner wall is continuously scraped off by the scraper 334 on the fixed rod. When the sludge concentration in the bucket reaches 3-5% or the operation is completed for 8 hours, the staff opens the baffle 333 of the discharge outlet 332 to complete the sewage discharge.

[0034] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A wastewater treatment device for water pollution control, characterized in that, The system includes a housing (1), a primary filter (2), a microfiltration device (3), a backwashing device (4), and a collection tank (5). The housing (1) is fixedly installed on one side for primary filtration of wastewater. The primary filter (2) is installed on one side of the primary filter (2). The microfiltration device (3) is used to filter wastewater through a reverse osmosis membrane and to periodically clean the inside of the microfiltration device (3). The backwashing assembly is fixedly installed on one side of the housing (1). The backwashing assembly uses the water filtered by the microfiltration device (3) to rinse the outside of the microfiltration device (3). The housing (1) is installed on one side for collecting the treated water.

2. The wastewater treatment device for water pollution control according to claim 1, characterized in that: The microfiltration device (3) includes a feed pipe (31), a limiting frame (32), a filter cartridge (33), a drive assembly (34), a transmission assembly (35), and a cleaning assembly (357; fixing rod; 36). The feed pipe (31) is fixedly installed on the limiting frame (32) and connected to the primary filtration device (2). The limiting frame (32) is symmetrically fixedly installed inside the housing (1). The filter cartridge (33) is rotatably installed on the limiting frame (32) and connected to the feed pipe (31). The drive assembly (34) 34) Installed in the middle of the filter cartridge (33) and fixed on the top of the housing (1), the drive assembly (34) is used to drive the filter cartridge (33) to rotate; the transmission assembly (35) is installed inside the filter cartridge (33), and the transmission assembly (35) is used to drive the cleaning assembly (357; fixed rod; 36) to move periodically inside the filter cartridge (33) to clean the filter cartridge (33) while the filter cartridge (33) rotates; the cleaning assembly (357; fixed rod; 36) is installed inside the filter cartridge (33).

3. A wastewater treatment device for water pollution control according to claim 2, characterized in that: The drive assembly (34) includes a fixed frame (341), a rectangular through slot (342), a drive motor (343), a drive pulley (344), a driven pulley (345), and a drive belt (346). The fixed frame (341) is fixedly installed above the housing (1). The drive motor (343) is fixedly installed on the fixed frame (341). The drive pulley (344) is fixedly installed at the output end of the drive motor (343). One end of the drive belt (346) is clamped on the drive pulley (344). The driven pulley (345) is fixedly installed in the middle of the filter cartridge (33). The driven pulley (345) is fixedly fixed in a ring on the filter cartridge (33). The other end of the drive belt (346) is clamped on the driven pulley (345). The fixed frame (341) has a rectangular through slot (342) through which the drive belt (346) passes.

4. A wastewater treatment device for water pollution control according to claim 3, characterized in that: The transmission assembly (35) includes a baffle (351), a waterproof plate (352), a driving gear ring (353), a transmission gear (354), a driven gear (355), a fixed plate (356), and a fixed rod. The baffle (351) is fixedly mounted on the limiting frame (32), the waterproof plate (352) is fixedly mounted on the fixed rod, the filter cartridge (33) is fixedly mounted with the driving gear ring (353), the driving gear ring (353) rotates with the rotation of the filter cartridge (33), one end of the fixed rod is fixedly mounted on the baffle (351), and the other end of the fixed rod is fixedly mounted on the baffle (351). One end passes through the waterproof plate (352) and is fixedly installed on the fixing plate (356). The fixing plate (356) is fixedly installed on the feed pipe (31) and the coverage area of ​​the fixing plate (356) is less than one-third of the cross-sectional area of ​​the feed pipe (31). The transmission gear (354) is rotatably installed on the fixing rod and the fixing rod limits the axial movement of the transmission gear (354). The driven gear (355) is rotatably installed on the fixing plate (356). The driving gear ring (353), the transmission gear (354) and the driven gear (355) mesh.

5. A wastewater treatment device for water pollution control according to claim 4, characterized in that: The cleaning assembly (357; fixed rod; 36) includes a reciprocating screw (361), a fixed bushing (362), a guide groove (363), meshing teeth (364), a cleaning disc (365), and a cleaning scraper (366). One end of the reciprocating screw (361) is fixedly mounted on the driven gear (355), and the other end of the reciprocating screw (361) is rotatably mounted with the fixed bushing (362). The fixed bushing (362) is fixedly mounted on the fixed plate (356), and the reciprocating screw (361) extends upwards... A guide groove (363) is provided at an offset, and the length of the guide groove (363) on the reciprocating screw (361) is the same as the length of the filter cartridge (33) at its maximum diameter. A meshing tooth (364) is engaged on the guide groove (363), and a cleaning disc (365) is fixedly installed on the meshing tooth (364). Limiting holes are arrayed on the cleaning disc (365), and a fixing rod passes through the limiting holes to limit the cleaning disc (365). A cleaning scraper (366) is installed on the cleaning disc (365).

6. A wastewater treatment device for water pollution control according to claim 5, characterized in that: The cleaning disc (365) is provided with a rectangular cavity (3651), and a movable block (3652) is fixedly installed inside the rectangular cavity (3651). A rotating column (3653) is fixedly installed on the top of the meshing teeth (364). A limit groove (3654) is opened on the movable block (3652), and the rotating column (3653) is rotatably installed on the limit groove (3654). When the meshing teeth (364) move to the end position along the guide groove (363), under the guidance of the guide groove (363), The meshing teeth (364) and the rotating column (3653) rotate, thereby changing the direction of the meshing teeth (364), causing the meshing teeth (364) to drive the moving block (3652) and the cleaning disc (365) to move in the opposite direction; the cleaning disc (365) is provided with permeable holes (3655) in an array except for the rectangular cavity (3651), and a one-way valve (3656) is fixedly installed in the permeable holes (3655). The flow direction of the one-way valve (3656) is from the side of the cleaning disc (365) closest to the water inlet pipe to the other side.

7. A wastewater treatment device for water pollution control according to claim 6, characterized in that: A hinge rod (3657) is fixedly installed on the cleaning disc (365), and a hinge sleeve (3658) is fixedly installed on the cleaning scraper (366); a limiting protrusion (3659) is provided on one side of the cleaning disc (365), and the limiting protrusion (3659) limits the rotation of one side of the cleaning scraper (366); the end of the cleaning scraper (366) is made of deformable rubber material.

8. A wastewater treatment device for water pollution control according to claim 7, characterized in that: A collection bucket (331) is fixedly installed on one side of the filter cartridge (33). The collection bucket (331) rotates with the rotation of the filter cartridge (33). A discharge port (332) is provided on the collection bucket (331). A stop block (333) is movably installed on the discharge port (332). A scraper (334) is fixedly installed on the fixed rod. The scraper (334) is fixed so that the dirt attached to the inner wall of the collection bucket (331) can be cleaned by the relative movement between the movable collection bucket (331) and the scraper (334).

9. A wastewater treatment device for water pollution control according to claim 8, characterized in that: The backwashing device (4) includes an overflow trough (41), a filter box (42), a filter plate (43), a water guide pipe (44), a pressurized water pump (45), a water delivery pipe (46), a support frame (47), and a high-pressure nozzle (48). The overflow trough (41) is located on one side of the housing (1). The filter box (42) is fixedly installed on the housing (1) and connected to the housing (1) through the overflow trough (41). A filter plate (43) is fixedly installed inside the filter box (42). A water guide pipe (48) is fixedly installed on the top of the filter box (42). 4) At one end, the water guide pipe (44) is fixedly installed at the inlet of the pressurized water pump (45). The pressurized water pump (45) is fixedly installed on the housing (1). The outlet of the pressurized water pump (45) is fixedly connected to a water supply pipe (46). The array of water supply pipes (46) is fixedly installed on the housing (1), and a high-pressure nozzle (48) is fixedly installed at the end of the water supply pipe (46). A support frame (47) is provided on the high-pressure nozzle (48) to support it, and the support frame (47) is fixedly installed inside the housing (1).

10. A wastewater treatment method for water pollution control, characterized in that, A wastewater treatment device for water pollution control, comprising any one of claims 1 to 9, wherein the method is as follows: S1: Introduce the wastewater to be treated into the feed inlet of the tank (1), control the influent flow rate to be 5-10 m³ / h, and the influent turbidity <200 NTU and COD <500 mg / L; the wastewater first enters the primary filter (2), which has a built-in 50-100 μm stainless steel filter screen. Under the action of gravity, it completes the preliminary filtration, removing suspended solids and impurities with a particle size >100 μm. The primary filtration time is controlled at 3-5 min, and the turbidity of the primary filtration effluent drops to <50 NTU; S2: The effluent from the initial filtration enters the filter cartridge (33) of the microfiltration device (3) through the feed pipe (31). The drive motor (343) of the drive assembly (34) is started and the speed is set to 30-60 r / min. The driven pulley (345) is driven by the drive pulley (344) and the drive belt (346), so that the filter cartridge (33) rotates continuously and uniformly on the limit frame (32). The wastewater is filtered by the built-in microfiltration membrane (polyvinylidene fluoride or polyethersulfone material) with a pore size of 0.1-0.5 μm in the filter cartridge (33). The operating pressure is controlled at 0.05-0.15 MPa and the membrane flux is maintained at 60-120 L / (m²·h). The filtrate flows through the membrane wall into the product water area at the bottom of the tank (1) and enters the collection tank (5) through the overflow trough (41). The turbidity of the product water is <0.2 NTU and SS is <5 mg / L. S3: During the rotation of the filter cartridge (33), the transmission assembly (35) starts synchronously: the active gear ring (353) fixed on the inner wall of the filter cartridge (33) rotates with the filter cartridge (33), driving the transmission gear (354) to rotate. The transmission gear (354) meshes with the driven gear (355), driving the reciprocating screw (361) to rotate at a speed of 10-20 r / min. The cleaning disc (365) engages with the guide groove (363) of the reciprocating screw (361) through the meshing teeth (364). Under the limiting action of the fixed rod, it reciprocates along the axial direction of the filter cartridge (33) at a speed of 0.05-0.1 m / s. The travel distance is equal to the effective length of the filter cartridge (33) (1.5-2 m / s). .0m); the cleaning scraper (366) maintains a unidirectional tilt angle under the action of the limiting protrusion (3659). That is, when it moves towards the transmission component (35), the rubber material at its end scrapes off the filter cake layer attached to the inner wall of the membrane with a contact pressure of 0.5-1.0kPa. When it moves towards the outlet pipe, the cleaning scraper (366) rotates inward along the hinge rod (3657) under the push of the water flow. At this time, the rubber material at the end of the cleaning scraper (366) does not contact the inner wall of the membrane. The detached pollutants enter the collection bucket (331) at the end of the filter cartridge (33) under the push of the cleaning disc (365). The reciprocating cleaning cycle is synchronized with the rotation cycle of the filter cartridge (33). Each reciprocating motion takes 2-3 minutes to complete. S4: When the filter cartridge (33) reaches the preset cycle (2 hours of continuous operation or the transmembrane pressure difference rises to 0.18 MPa), the backwashing program is automatically started: the permeate in the collection tank (5) enters the filter box (42) through the overflow tank (41), and after secondary filtration through the filter plate (43) (50 μm), it is delivered to the high-pressure nozzle (48) by the pressurized water pump (45) at a pressure of 0.3-0.5 MPa. The spray angle is 120° and the flow rate is 5-10 m / s to perform pulse flushing on the outer wall of the filter cartridge (33). Each flush lasts for 30-60 seconds. The backwashing frequency is set to once every 2 hours, or automatically adjusted according to the feedback from the online turbidity meter. S5: The collection bucket (331) rotates synchronously with the filter cartridge (33), and the concentrated sludge attached to its inner wall is continuously scraped off by the scraper (334) on the fixed rod. The gap between the scraper (334) and the inner wall of the collection bucket (331) is maintained at 1-2 mm. When the sludge concentration in the collection bucket (331) reaches 3-5% (solid content) or when it has been running for 8 hours, the staff opens the baffle (333) of the discharge port (332) to collect the sludge inside and prevent sludge accumulation. S6: Throughout the entire treatment process, the PLC control system monitors the inlet water pressure, product water flow rate, transmembrane pressure difference, filter cartridge (33) rotation speed, and cleaning disc (365) position in real time. When the product water turbidity > 0.5 NTU or TMP > 0.2 MPa, the system automatically alarms and extends the backwashing time to 90 s; when TMP > 0.25 MPa or the filtration flux decreases by > 20%, the system triggers the shutdown protection and starts the chemical cleaning program (1% citric acid circulation cleaning for 30 min); finally, the product water stays in the collection tank (5) for > 30 min, and after COD < 50 mg / L, ammonia nitrogen < 5 mg / L, and total phosphorus < 0.5 mg / L, it meets the standards for discharge or reuse.

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