Dual-route switching system and its operating method in a sewage treatment plant

Abstract

The two-way switching system and its operating method for a sewage treatment plant includes an inlet basin connected to a dry season treatment system and a wet season treatment system, respectively. The dry season treatment system includes a fine-coarse mixing grate connected in series to a settling basin, a membrane grate device, an AAO combined basin, an MER reaction basin, and a first UV disinfection tank. The wet season treatment system includes a self-cleaning grate connected in series to a flow control valve, a combined flow regulation reservoir, a magnetic sedimentation system, a fiber rotary disk filter, and a second UV disinfection tank. The inlet basin is equipped with a liquid level sensor, a sludge concentration sensor, and a flow rate sensor. A selector valve is installed in front of the self-cleaning grate, and the liquid level sensor, sludge concentration sensor, and flow rate sensor are connected to a control unit.

Description

[Technical Field]

[0001] The present invention relates to the technical field of wastewater treatment, and more particularly to a two-way switching system and its operating method in a wastewater treatment plant. [Background technology]

[0002] In the field of wastewater treatment, it is extremely important to design and implement an effective treatment plan that takes into account the characteristics of wastewater under different seasons and climatic conditions. Especially during the rainy season, when large amounts of rainwater enter a wastewater treatment system, high flow rates and high concentrations of suspended solids create challenges, placing greater demands on the normal operation of wastewater treatment plants. Conventional wastewater treatment systems often lack the ability to automatically adjust treatment routes according to seasonal changes. During the rainy season, large amounts of rainwater flow into the wastewater, causing a rapid increase in the concentration of suspended solids and impurities in the wastewater. A single treatment process cannot cope with this high load, leading to reduced treatment efficiency and even exceeding treatment capacity, potentially causing environmental pollution. Furthermore, during the dry season, the amount of wastewater is relatively small, but the concentration of pollutants is high, requiring more precise treatment measures. Therefore, existing systems have limited flexibility and adaptability. Therefore, a dual-route switching system is urgently needed in wastewater treatment plants, which automatically selects the optimal treatment route based on the characteristics of wastewater in different seasons, thereby optimizing treatment efficiency and costs.

[0003] Furthermore, during the rainy season, large amounts of rainwater entering the treatment system along with suspended matter such as leaves, plastic bags, and foam can clog inlets, self-cleaning grates, and other important equipment, seriously affecting the efficiency and quality of water treatment. Currently, the main methods for treating suspended matter involve manual removal and the use of simple hauling tools such as net bags and long-handled hauling nets. However, these traditional methods have obvious limitations, such as reduced efficiency, high labor intensity, and poor safety, and they also make it difficult to respond and treat quickly when suspended matter is concentrated. Summary of the Invention [Problem to be solved by the invention]

[0004] The technical problem to be solved by this invention is to propose a dual-route switching system and its operating method for a sewage treatment plant equipped with a dry season treatment system and a rainy season treatment system, which automatically selects the optimal treatment route by monitoring the liquid level, sludge concentration, and flow rate in the inlet basin in real time and combining it with intelligent control, and achieves automatic adaptation to the characteristics of sewage in different seasons, thereby significantly improving the operating efficiency and environmental adaptability of the sewage treatment plant. This system not only overcomes the limitations of conventional sewage treatment technology, but also provides an innovative solution for realizing more economical sewage treatment with a low environmental impact. [Means for solving the problem]

[0005] In order to solve the above technical problems, the technical means adopted in the present invention are: The inlet ditch tank is connected to the dry season treatment system and the wet season treatment system, respectively; The dry season treatment system has a fine and coarse mixing grid, which is sequentially connected to a sedimentation tank, a membrane grid device, an AAO combined tank, an MER reaction tank and a first ultraviolet disinfection tank; The rainy season treatment system has a self-cleaning grid, which is sequentially connected to a flow control valve, a combined flow regulation reservoir, a magnetic sedimentation system, a fiber rotating disk filter, and a second ultraviolet disinfection tank; A two-way switching system for a wastewater treatment plant, in which a liquid level sensor, a sludge concentration sensor and a flow rate sensor are provided in an inlet trough tank, a switching valve is provided in front of a self-cleaning grate, the liquid level sensor, the sludge concentration sensor and the flow rate sensor are connected to a control unit, and the control unit is used to control the operation of the switching valve.

[0006] Preferably, the system further comprises a sludge treatment system having a sludge pond, in which dewatering is performed using a centrifugal dehydrator, a sludge transport device is provided at the sludge discharge outlet of the centrifugal dehydrator, and sludge from the MER reaction pond is transported to the sludge pond via a sludge transport device.

[0007] Preferably, the MER reaction tank is connected to the AAO combined tank via a sludge circulation pipe, and a phosphorus solution circulation pipe is provided between the MER reaction tank and the AAO combined tank.

[0008] Preferably, the sludge from the magnetic settling system and the fiber rotating disc filter basin is treated by a centrifugal dewatering machine.

[0009] Preferably, the MER reaction pond is equipped with an acid addition device, and the AAO combined pond is equipped with an aeration device and a carbon supply device.

[0010] Preferably, a transition passage is provided between the self-cleaning grate and the switching valve, and an emergency floating matter lifting device is provided in the transition passage, and the emergency floating matter lifting device is used to lift up excess floating matter.

[0011] Preferably, the emergency floating object salvage device has a curved guide rod, a salvage net is arranged between two curved guide rods, a sliding fastener is arranged on the salvage net, the sliding fastener is arranged to slide along the curved guide rods, both ends of the salvage net are used to attach to the towing rope, the curved guide rods are U-shaped guide rods, the planes on which the two U-shaped guide rods are located are parallel to each other, and the lower half of the U-shaped guide rod is arranged to be submerged in water.

[0012] Preferably, the sliding fastener has a rotating seat, the rotating seat is rotatably connected to the semi-annular sliding sleeve, at least four rotating seats are arranged, the four rotating seats are respectively attached to four corners of the hauling net, and the semi-annular sliding sleeve is arranged to slide on the bending guide rod.

[0013] The arc angle of the semi-annular sliding sleeve is in the range of 180 to 360 degrees, and an internal retaining rod is provided at each of the two ends of the semi-annular sliding sleeve, and a rolling ball is provided at the end of the internal retaining rod, and the rolling ball is arranged to roll and engage with the bending guide rod.

[0014] Preferably, a hanging rod is provided at the side of the bending guide rod, the diameter of the hanging rod is smaller than that of the bending guide rod and is smaller than the distance between the two rolling balls, the semi-annular sliding sleeve is provided to slide along the bending guide rod, and the hanging rod can pass through the curved opening of the semi-annular sliding sleeve, and the hanging rod is provided to connect with the support frame.

[0015] A counterweight is provided at one end of the hauling net, and at least four pull rings are provided on the hauling net, and the pull rings are connected to a towing rope, which is towed by mechanical equipment or by human power. The hauling net has four main load belts, which are surrounded by each other to form a rectangular structure, and mesh bags are woven around the four main load belts, and the length of the hauling net is greater than the distance between the curved mouths of the U-shaped guide rod.

[0016] A method for operating a dual-path switching system in a wastewater treatment plant includes the steps of: The liquid level sensor, sludge concentration sensor, and flow rate sensor installed in the inflow channel tank are used to measure the liquid level H and sludge concentration C. s Step 1: monitoring and collecting the flow velocity V and The liquid level elevation is in meters (m), the sludge concentration is in milligrams per liter (mg / L), and the flow rate is in meters per second (m / s). The time t is the scanning period, and the average liquid level H avg , average sludge concentration C s,avg , and the mean flow velocity V avg Step 2: Calculate Liquid level warning value H0, sludge concentration warning value C s0 The warning values ​​including the warning value V0 of the flow rate are preset, and the liquid level is used as the main indicator for determining the rainy season, and the sludge concentration and flow rate are used as secondary indicators. The average liquid level H is calculated based on the following formula: avg , average sludge concentration C s,avg , and the mean flow velocity V avg Step 3: setting the threshold for the rainy season working conditions by performing a weight analysis on X=w H ·(H avg-H0)+w Cs ·(C s,avg -C s,0 )+w V ·(V avg -V0) (where wH, wCs, and wV are the weighting coefficients for the liquid level, sludge concentration, and flow velocity, respectively, and satisfy the equation wH+wCs+wV=1, and X is the overall index.) Step 4: setting a threshold X0 of the comprehensive index for determining the current working conditions; if X>X0, determining that the working conditions are in the rainy season and switching to the rainy season processing system; if X≦X0, determining that the working conditions are not in the rainy season and switching to the dry season processing system; If it is determined that it is the dry season, the control unit sends a command to the switching valve to adjust the switching valve to a set position that directs it to the dry season treatment system, and if it is determined that it is the rainy season, the control unit sends a command to the switching valve to adjust the switching valve to a set position that directs it to the rainy season treatment system.

[0017] Preferably, when there is too much floating matter at the entrance of the self-cleaning grate, an emergency floating matter lifting device is activated to lift the floating matter in batches; The salvage process, All the sliding fasteners are fitted onto one end of the bending guide rod, and one end of the hauling net is pulled and slid by the towing rope, and the other end of the hauling net is pulled in cooperation with the towing rope. When the sliding fasteners at one end of the hauling net reach the other side of the bending guide rod and are pulled, the hauling net is fully deployed, and the towing ropes connected to both ends of the hauling net are simultaneously lifted to haul up the floating objects on the surface of the wastewater. After one hauling is completed, the hauling net is similarly positioned below the floating objects, so that the process of positioning the hauling net is not interfered with by the floating objects. [Effects of the Invention]

[0018] The present invention has the following beneficial effects:

[0019] The system of the present invention, which comprises a dry season treatment system and a rainy season treatment system, automatically selects the optimal treatment path by combining real-time monitoring of the liquid level, sludge concentration, and flow rate in the inlet basin and intelligent control, and achieves automatic adaptation to the characteristics of wastewater in different seasons, greatly improving the operating efficiency and environmental adaptability of the wastewater treatment plant. This system not only overcomes the limitations of conventional wastewater treatment technologies, but also provides an innovative solution for achieving more economical wastewater treatment with a low environmental impact.

[0020] The system and method of the present invention can automatically adjust the wastewater treatment route according to changes in season and water volume, effectively meeting the demands of wastewater treatment in both dry and rainy seasons. In addition, the integrated emergency floating debris recovery device improves the system's emergency treatment capacity and maintenance work efficiency, and as a whole improves the operational efficiency and flexibility of the wastewater treatment plant.

[0021] The emergency floating object recovery device is designed by combining a flexible bending guide rod, a deployable recovery net, and a self-adaptive sliding fastener, which can quickly and effectively collect and remove floating objects on the water surface without interrupting the water treatment process, greatly improving the operating efficiency and safety of wastewater treatment plants. [Brief explanation of the drawings]

[0022] The present invention will now be further described in conjunction with the accompanying drawings and examples.

[0023] [Figure 1] 1 is a process flow diagram of the present invention. [Figure 2] FIG. 2 is a three-dimensional structural diagram of an emergency floating object lifting device. [Figure 3] FIG. 3 is an enlarged view of part A in FIG. 2. [Figure 4] FIG. 1 is a side view of an emergency floating object recovery device (in use state 1). [Figure 5] FIG. 2 is a side view of an emergency floating object salvage device (in use state 2). [Figure 6] FIG. 10 is a structural diagram showing the connection between the lifting net and the sliding fastener of the emergency floating object lifting device. [Figure 7] FIG. 2 is a top view of the emergency floating object lifting device. [Figure 8] FIG. 10 is a diagram showing the position where an emergency floating object recovery device is installed. DETAILED DESCRIPTION OF THE INVENTION

[0024] As shown in FIG. 1-8, in a preferred embodiment, the two-way switching system in the sewage treatment plant has an inlet basin 1, which is connected to the dry season treatment system and the wet season treatment system respectively.

[0025] The dry season treatment system has a fine and coarse mixing grate 2, which is sequentially connected to a settling tank 3, a membrane grate device 4, an AAO combined tank 5, an MER reaction tank 6, and a first ultraviolet disinfection tank 7. The residue in the fine and coarse mixing grate 2 is discharged by a residue discharge device 20, which is a spiral conveyor or the like.

[0026] The rainy season treatment system has a self-cleaning grate 13, which is connected in series with a flow control valve 14, a combined flow regulation reservoir 15, a magnetic sedimentation system 16, a fiber rotating disk filter 17 and a second ultraviolet disinfection tank 18.

[0027] The inlet groove tank 1 is provided with a liquid level sensor, a sludge concentration sensor and a flow rate sensor, and a switching valve 24 is provided in front of the self-cleaning grate 13. The liquid level sensor, the sludge concentration sensor and the flow rate sensor are connected to a control unit, and the control unit is used to control the operation of the switching valve 24.

[0028] The inlet basin 1 serves as the water inlet point connecting the dry-season treatment system and the wet-season treatment system. The dry-season treatment system includes a fine-coarse mixing grate 2, a grit chamber 3, a membrane grate device 4, an AAO combined basin 5, a MER reaction basin 6, and a first UV disinfection tank 7. The wet-season treatment system includes a self-cleaning grate 13, a flow control valve 14, a combined flow regulation reservoir 15, a magnetic sedimentation system 16, a fiber turntable filter 17, and a second UV disinfection tank 18. The dry-season treatment system and the wet-season treatment system are switched via a selector valve 24. The selector valve 24 is located in front of the self-cleaning grate 13 and is automatically opened and closed by the control unit in response to signals from the liquid level sensor, sludge concentration sensor, and flow rate sensor in the inlet basin 1, achieving switching between the dry-season treatment path and the wet-season treatment path. The control unit can be a Siemens SIMATIC S7 series PLC, suitable for a variety of large and small automation tasks.

[0029] Furthermore, the system of the present invention further includes a sludge treatment system, which has a sludge tank 12, in which dewatering is performed using a centrifugal dehydrator 11, a sludge discharge device 10 is provided at the sludge discharge outlet of the centrifugal dehydrator 11, and the sludge in the MER reaction tank 6 is transported to the sludge tank 12 via a sludge transport device.

[0030] The sludge treatment system has a sludge tank 12, in which dewatering is performed using a centrifugal dehydrator 11, and a sludge discharge outlet is provided with a sludge discharge device 10. Sludge from the MER reaction tank 6 is transported to the sludge tank 12 via a sludge transport device. Sludge generated in the magnetic settling system 16 and the fiber rotating disk filter tank 17 is also treated by the centrifugal dehydrator 11.

[0031] Furthermore, the MER reaction tank 6 is connected to the AAO combined tank 5 via a sludge circulation pipe, and a phosphorus solution circulation pipe is provided between the MER reaction tank 6 and the AAO combined tank 5.

[0032] The MER reaction tank 6 is connected to the AAO combined tank 5 via a sludge circulation pipe, and an additional phosphorus solution circulation pipe is installed.

[0033] Furthermore, the sludge from the magnetic settling system 16 and the fiber rotating disk filter 17 is treated by the centrifugal dewatering machine 11.

[0034] Furthermore, the MER reaction tank 6 is equipped with an acid addition device 21, and the AAO combined tank 5 is equipped with an aeration device 22 and a carbon supply device 23.

[0035] An acid addition device 21 is installed in the MER reaction pond 6, and an aeration device 22 and a carbon supply device 23 are installed in the AAO combined pond 5.

[0036] Furthermore, a transition passage 25 is provided between the self-cleaning grate 13 and the switching valve 24, and an emergency floating matter lifting device 9 is provided in the transition passage 25, which is used to lift up excess floating matter.

[0037] A transition passage 25 is provided between the self-cleaning grate 13 and the switching valve 24, and the built-in emergency floating object retrieval device 9 includes components such as a bent guide rod 901, a retrieval net 902, a sliding fastener 903, and a towing rope 904, and is used to deal with situations where there is too much floating object.

[0038] The emergency floating object salvage device 9 has a curved guide rod 901, a salvage net 902 is arranged between two curved guide rods 901, a sliding fastener 903 is arranged on the salvage net 902, the sliding fastener 903 is arranged so as to slide along the curved guide rod 901, and both ends of the salvage net 902 are used to attach a towing rope 904.

[0039] The bending guide rods 901 may be arc-shaped rods or semicircular rods, etc., and the lower halves of the bending guide rods 901 are submerged in water, and the sliding fasteners 903 are fitted to the bending guide rods 901. In use, all of the sliding fasteners 903 are fitted to one end of the bending guide rods 901, and one end of the hauling net 902 is pulled and slid by the towing rope 904, and the other end of the hauling net 902 is pulled in cooperation with the towing rope 904. When the sliding fastener 903 at one end of the hauling net 902 is pulled to the other side of the bending guide rod 901, the hauling net 902 is fully unfolded. When there are too many floating objects on the surface of the wastewater, the towing ropes 904 connected to both ends of the hauling net 902 are simultaneously pulled up to haul up the floating objects on the surface of the wastewater. After one lifting is completed, the lifting net 902 is similarly placed below the floating object so that the placement process of the lifting net 902 is not interfered with by the floating object.

[0040] Furthermore, the curved guide rod 901 in this embodiment is a U-shaped guide rod, the planes of the two U-shaped guide rods are parallel to each other, and the lower half of the U-shaped guide rod is submerged in water.

[0041] The hauling net 902 is located between the two U-shaped guide rods, and the length of the hauling net 902 is greater than the distance between the curved mouths of the U-shaped guide rods, and the width of the hauling net 902 is slightly greater than the distance between the two U-shaped guide rods. The hauling net 902 shown in Figure 1 is in a taut state, but it is preferable that the hauling net 902 actually used is a net bag with a concave structure, which helps to haul up more floating objects at one time.

[0042] Furthermore, the sliding fastener 903 has a rotating seat 903.1, which is rotatably connected to a semi-annular sliding sleeve 903.2. At least four rotating seats 903.1 are arranged, and the four rotating seats 903.1 are respectively attached to the four corners of the hauling net 902, and the semi-annular sliding sleeves 903.2 are arranged to slide on the bending guide rod 901.

[0043] The semi-annular sliding sleeve 903.2 is rotatably coupled with the rotating seat 903.1, and the semi-annular sliding sleeve 903.2 is adapted to fit the bending guide rod 901, and the semi-annular sliding sleeve 903.2 can rotate self-adaptively according to the change in the direction of the hauling net 902. The rotating seat 903.1 and the hauling net 902 can be connected by a fastening member or by a knotting thread.

[0044] Furthermore, the arc angle of the semi-annular sliding sleeve 903.2 is in the range of 180 to 360 degrees, and the two ends of the semi-annular sliding sleeve 903.2 are respectively provided with retaining rods 903.3, and the ends of the retaining rods 903.3 are provided with rolling balls 903.4, which are arranged to roll and engage with the bending guide rod 901.

[0045] The rolling balls 903.4 are used to reduce the resistance between the sliding fastener 903 and the bending guide rod 901, and help the sliding fastener 903 to slide smoothly on the bending guide rod 901.

[0046] Furthermore, a hanging rod 905 is provided on the side of the bending guide rod 901, and the diameter of the hanging rod 905 is smaller than that of the bending guide rod 901 and is also smaller than the distance between the two rolling balls 903.4. A semi-annular sliding sleeve 903.2 is provided to slide along the bending guide rod 901, and the hanging rod 905 can pass through the curved opening of the semi-annular sliding sleeve 903.2, and the hanging rod 905 is provided to connect with the support frame.

[0047] The support frame suspends the two bending guide rods 901 in the water via the hanging rods 905, and the bending guide rods 901 are not completely submerged in the water, which makes it easy for the sliding fasteners 903 to move smoothly from one end to the other of the bending guide rods 901. Since the hanging rods 905 affect the operation of the sliding fasteners 903, in order to avoid collision between the sliding fasteners 903 and the hanging rods 905, the structure of the sliding fasteners 903 is detailed for the emergency floating object salvage device 9. The specific structure is as follows: The semi-annular sliding sleeve 903.2 is not completely closed, and there is a sufficient gap between the two rolling balls 903.4 to allow the suspension rod 905 to pass through, and the diameter of the suspension rod 905 is smaller than that of the bending guide rod 901, so that the suspension rod 905 has an L-shape, which not only allows the suspension rod 905 to pass through the sliding fastener 903 but also prevents it from slipping out of the bending guide rod 901. When it is necessary to lift up the floating object, the lifting net 902 can be completely detached from the bending guide rod 901.

[0048] Furthermore, a counterweight 906 is provided at one end of the hauling net 902 .

[0049] When the hauling net 902 is attached to the bent guide rod 901, a downward pulling force is generated in the counterweight 906, and one end of the hauling net 902 is smoothly pulled downward.

[0050] Furthermore, the hauling net 902 is provided with at least four pulling rings 907, which are connected to a towing rope 904, and the towing rope 904 is pulled by mechanical equipment or by human power.

[0051] This device is sometimes used as an emergency device, and can be started when there is too much floating material and the self-cleaning grate 13 cannot process a large amount of floating material in a short time. The towing method can be manual towing, but if there is not enough manpower to remove the floating material, a winch can be used to pull the towing rope 904.

[0052] Furthermore, the hauling net 902 has four main load straps 902.1, which are surrounded by a rectangular structure and have mesh bags attached to them, and the length of the hauling net 902 is greater than the distance between the curved openings of the U-shaped guide rods.

[0053] The four main load straps 902.1 may be made of nylon, which is used to ensure sufficient mechanical strength while still providing some flexibility.

[0054] This device is used in front of the self-cleaning grate 13. Some sewage treatment plants have adopted dry season and rainy season treatment processes, with the rainy season referring to the period when rainwater is sufficient. When the water level rises in the rainy season, a lot of suspended matter is generated, and these suspended matter can pass through the self-cleaning grate 13 before entering the rainy season treatment process. When the self-cleaning grate 13 cannot quickly clean up a large amount of suspended matter, this device can be used for emergency treatment.

[0055] The functions of other equipment in this system are as follows:

[0056] The self-cleaning grate 13 is a pre-treatment device used at the front of a water treatment system. Its primary function is to trap and remove large suspended solids, floating debris, and solid particles from the water, protecting downstream water treatment devices from damage. The design of the self-cleaning grate 13 allows sludge accumulated on the grate to be automatically removed during operation, ensuring continuous, stable water flow and system operating efficiency without the need for interruptions or manual intervention. The operating principle of the self-cleaning grate 13 is as follows: The grate frame is used to support and secure the grate and is usually made of a corrosion-resistant material such as stainless steel or glass fiber reinforced plastic. The grate plate consists of a series of parallel grate strips, with the gaps between the strips designed according to the size of the solid particles required to be blocked. The cleaning device, which includes a drive mechanism, cleaning brushes or rake teeth, and a control device, is used to remove dirt from the grate plate.

[0057] AAO (Anaerobic-Anoxic-Oxic) combined ponds, also known as A2O (Anaerobic-Anoxic-Oxic) ponds, are a widely used biological treatment method in wastewater treatment, primarily used for denitrification and phosphorus removal. This method combines anaerobic, anoxic, and aerobic environments to achieve highly efficient removal of organic matter, nitrogen, and phosphorus from wastewater. The detailed working principles and components of AAO combined ponds are as follows: 1. The anaerobic stage (anaerobic) releases phosphorus and amminates some of the organic matter. Under anaerobic conditions, phosphate-accumulating bacteria release the phosphate stored in their bodies and may also decompose some of the organic matter, providing conditions for phosphorus absorption in the subsequent aerobic stage. 2. The anoxic stage (anoxic) reduces nitrate to nitrogen gas through denitrification. In an oxygen-deficient environment, denitrifying bacteria achieve nitrogen removal by using organic matter as electron carriers to reduce nitrates to nitrogen gas. 3. The aerobic stage (Oxic) oxidizes and nitrifies organic matter and absorbs phosphorus. In an aerobic environment, aerobic microorganisms oxidize organic matter to carbon dioxide and water, and nitrifying bacteria may convert amino nitrogen to nitrite and nitrate. Phosphate-accumulating bacteria reabsorb phosphorus in this stage and store it within their cells.

[0058] An MBR (Membrane Bioreactor) reactor, also known as a membrane bioreactor, is a highly efficient wastewater treatment system that combines biological treatment technology with membrane separation technology. The core of the MBR system is the use of a membrane assembly for solid-liquid separation, replacing the traditional secondary sedimentation tank. This maintains a relatively high activated sludge concentration within the biological treatment unit, thereby improving biochemical treatment efficiency and wastewater quality. The activated sludge (microorganisms) in the MBR reactor decomposes organic and some inorganic substances in the water under aerobic or anaerobic conditions, biologically decomposing and converting them, producing carbon dioxide, water, and new materials. Microbial growth and metabolic activity continue within the MBR, forming a high-concentration biofilm and suspended activated sludge. Submerged or external membrane assemblies are installed within the MBR reactor, and these membrane assemblies can be flat-plate, tubular, or hollow-fiber membranes. The membrane assembly functions as a filter, blocking activated sludge and suspended solids, allowing only clean water to pass through and separating solids from the liquid. The clean water (permeate) that has passed through the membrane assembly has clean water quality and contains very little suspended matter, so it can be directly discharged or reused.

[0059] Fiber turntable filters are highly efficient water treatment equipment primarily used in the deep treatment stage of wastewater treatment plants to remove suspended solids, microorganisms, and some dissolved organic matter from water to meet discharge standards or reuse water quality requirements. These devices primarily perform functions such as filtration, biodegradation, and disinfection, particularly for the purpose of removing suspended solids, turbidity, color, and some pathogens from wastewater. The fiber turntable, the core component of a fiber turntable filter, is typically made of a large amount of elongated fiber bundles; that is, the fiber bundles are fixed to the turntable, which is attached to the filter via a central shaft and can rotate slowly. When the wastewater to be treated enters the filter, the water flow is able to pass through the gaps in the fiber bundles, and the surface area of ​​the fiber bundles is large enough to capture suspended solids and glue in the water, thereby fulfilling the filtering function. The special structure of the fiber bundles allows the water flow to create turbulence as it passes through, improving the filtration effect and preventing clogging of the fiber bundles.

[0060] The magnetic sedimentation system is a highly efficient water treatment technology used to remove suspended solids, gels, some dissolved substances, and microorganisms from water. This system combines conventional mixed flocculation and flocculation with the addition of magnetic granules to enhance the sedimentation effect, achieving faster and more thorough water purification. The basic operating principle of the magnetic sedimentation system is as follows: When magnetic granules are added to conventional mixed flocculation and flocculation, these magnetic granules bind to suspended solids and gels in the water, forming so-called "magnetic flocs." Because the specific gravity of the magnetic granules is much higher than that of water, the settling rate of the magnetic flocs is significantly higher. The system's operating process is as follows: First, a flocculant (such as polyaluminum chloride (PAC)) and a coagulant (such as polyacrylamide (PAM)) are added to the water to be treated, promoting the coagulation of suspended solids and gels into larger flocs. When magnetic granules (magnetic powder) are added during the flocculation process, the magnetic powder binds to the floc and forms magnetic floc. Because of its increased specific gravity, the magnetic floc can settle in the sedimentation tank at a much faster rate than regular floc, typically over a few hours, whereas conventional sedimentation can require several days. After settling, the magnetic floc can be recovered using magnetic separation technology (e.g., a magnetic drum), allowing the magnetic powder to be reused and reducing chemical consumption. The supernatant (water from which most suspended solids have been removed) is collected and sent to the next treatment stage (disinfection, deep treatment, etc.).

[0061] Combined detention basins are primarily used to treat and control the combined flow of stormwater and sewage in combined drainage systems. In combined systems, stormwater and domestic or industrial wastewater share the same pipeline system. While such systems operate well on sunny days, during heavy rainfall, the combined flow of stormwater and sewage may exceed the treatment capacity of the wastewater treatment plant, leading to the direct discharge of untreated sewage into the water body and causing environmental pollution. To solve this problem, combined detention basins are designed to store this excess combined flow and gradually treat and discharge it after the weather improves. The working process is as follows: When rain begins, stormwater and sewage flow merge into the detention basin through the combined pipeline system. At the beginning of a rainfall, the stormwater in the combined flow contains higher concentrations of pollutants (initial stormwater), and this stormwater may be collected preferentially. When the volume of the combined flow exceeds the treatment capacity of the sewage treatment plant, the detention reservoir begins to store the excess water. The capacity of the detention reservoir is usually designed to handle a certain intensity of rainfall and prevent the combined flow from being directly discharged untreated. After the rainfall ends, the combined flow in the detention reservoir is gradually pumped to the sewage treatment plant via a pumping station or under gravity for treatment. This process is usually controllable, preventing the sewage treatment plant from operating overload again.

[0062] A method for operating a two-way switching system in a wastewater treatment plant includes the following steps:

[0063] Step 1: Using the liquid level sensor, sludge concentration sensor, and flow rate sensor installed in the inflow channel tank 1, the liquid level height H and sludge concentration C s and flow velocity V are monitored and collected.

[0064] The liquid level elevation is in meters (m), the sludge concentration is in milligrams per liter (mg / L), and the flow rate is in meters per second (m / s).

[0065] Step 2: The time t is the scanning period, and the average liquid level H avg , average sludge concentration C s,avg , and the mean flow velocity Vavg Calculate.

[0066] Step 3: Liquid level warning value H0, sludge concentration warning value C s0 The warning values ​​including the warning value V0 of the flow rate are preset, and the liquid level is used as the main indicator for determining the rainy season, and the sludge concentration and flow rate are used as secondary indicators. The average liquid level H is calculated based on the following formula: avg , average sludge concentration C s,avg , and the mean flow velocity V avg The threshold for working conditions in the rainy season is set by performing a weight analysis on the above. X=w H ·(H avg -H0)+w Cs ·(C s,avg -C s,0 )+w V ·(V avg -V0)

[0067] (WH, WCS, and WV are the weighting factors for the liquid level, sludge concentration, and flow velocity, respectively, and WH + WCS + WV = 1, and X is the overall index.)

[0068] Step 4: Set the threshold X0 of the comprehensive index to determine the current working conditions. If X>X0, it is determined that the working conditions are those of the rainy season and switch to the rainy season processing system; if X≦X0, it is determined that the working conditions are not those of the rainy season and switch to the dry season processing system.

[0069] Step 5: If it is determined that it is the dry season, the control unit sends a command to the switching valve 24 to adjust the switching valve 24 to a set position that directs it to the dry season treatment system, and if it is determined that it is the rainy season, the control unit sends a command to the switching valve 24 to adjust the switching valve 24 to a set position that directs it to the rainy season treatment system.

[0070] If there is too much floating matter at the entrance of the self-cleaning grate 13, the emergency floating matter lifting device 9 is activated to lift the floating matter batchwise. The lifting process is as follows:

[0071] All the sliding fasteners 903 are fitted onto the bending guide rods 901 from one end of the bending guide rods 901 .

[0072] One end of the hauling net 902 is pulled by the towing rope 904 and slides, and the other end of the hauling net 902 is pulled in cooperation with the towing rope 904.

[0073] When the sliding catch 903 at one end of the lifting net 902 is pulled to the other side of the bending guide rod 901, the lifting net 902 is fully deployed.

[0074] The towing ropes 904 connected to both ends of the hauling net 902 are simultaneously lifted up to pull up any floating matter on the surface of the wastewater.

[0075] After one lifting is completed, the lifting net 902 is similarly placed below the floating object so that the placement process of the lifting net 902 is not interfered with by the floating object.

[0076] The above embodiments are merely preferred technical means of the present invention, and should not be regarded as limitations on the present invention. The technical means described in the claims, including equivalents of the technical features in the technical means described in the claims, are the protection scope of the present invention. That is, equivalent replacements and improvements made within this scope also fall within the protection scope of the present invention.

[0077] (Addendum) (Appendix 1) The inlet ditch tank (1) is connected to the dry season treatment system and the rainy season treatment system, respectively; The dry season treatment system has a fine-coarse mixing grate (2), which is connected in series to a settling tank (3), a membrane grate device (4), an AAO combined tank (5), an MER reaction tank (6) and a first ultraviolet disinfection tank (7); The rainy season treatment system has a self-cleaning grate (13), which is connected in series with a flow control valve (14), a combined flow regulation reservoir (15), a magnetic sedimentation system (16), a fiber rotating disk filter (17) and a second ultraviolet disinfection tank (18); The inlet trough tank (1) is provided with a liquid level sensor, a sludge concentration sensor and a flow rate sensor, and a switching valve (24) is provided in front of the self-cleaning grate (13), and the liquid level sensor, the sludge concentration sensor and the flow rate sensor are connected to a control unit, and the control unit is used to control the operation of the switching valve (24). A two-way switching system for a sewage treatment plant.

[0078] (Appendix 2) The system further includes a sludge treatment system, the sludge treatment system having a sludge tank (12), dewatering the sludge tank (12) using a centrifugal dehydrator (11), a sludge discharge device (10) provided at a sludge discharge outlet of the centrifugal dehydrator (11), and sludge from the MER reaction tank (6) being transported to the sludge tank (12) via the sludge transport device (10). 2. A two-way switching system for a sewage treatment plant according to claim 1.

[0079] (Appendix 3) The MER reaction tank (6) is connected to the AAO combined tank (5) through a sludge circulation pipe, and a phosphorus solution circulation pipe is provided between the MER reaction tank (6) and the AAO combined tank (5). 2. A two-way switching system for a sewage treatment plant according to claim 1.

[0080] (Appendix 4) The sludge from the magnetic settling system (16) and the fiber rotating disk filter (17) is treated by the centrifugal dewatering machine (11). 3. A two-way switching system for a sewage treatment plant according to claim 2.

[0081] (Appendix 5) The MER reaction tank (6) is equipped with an acid addition device (21), and the AAO combined tank (5) is equipped with an aeration device (22) and a carbon supply device (23). 2. A two-way switching system for a sewage treatment plant according to claim 1.

[0082] (Appendix 6) A transition passage (25) is provided between the self-cleaning grate (13) and the switching valve (24), and an emergency floating matter lifting device (9) is provided in the transition passage (25), and the emergency floating matter lifting device (9) is used to lift excess floating matter. 2. A two-way switching system for a sewage treatment plant according to claim 1.

[0083] (Appendix 7) The emergency floating object salvage device (9) has a curved guide rod (901), a salvage net (902) is arranged between two curved guide rods (901), a sliding fastener (903) is arranged on the salvage net (902), the sliding fastener (903) is arranged to slide along the curved guide rod (901), both ends of the salvage net (902) are used to attach tow ropes (904), the curved guide rods (901) are U-shaped guide rods, the planes of the two U-shaped guide rods are parallel to each other, and the lower half of the U-shaped guide rod is arranged to be submerged in water. 7. A two-way switching system for a sewage treatment plant according to claim 6.

[0084] (Appendix 8) The sliding fastener (903) has a rotating seat (903.1), the rotating seat (903.1) is rotatably connected to a semi-annular sliding sleeve (903.2), at least four rotating seats (903.1) are arranged, the four rotating seats (903.1) are respectively attached to the four corners of the hauling net (902), and the semi-annular sliding sleeve (903.2) is arranged to slide on the bending guide rod (901). 8. A two-way switching system for a sewage treatment plant according to claim 7.

[0085] (Appendix 9) The arc angle of the semi-annular sliding sleeve (903.2) is in the range of 180-360°, and two ends of the semi-annular sliding sleeve (903.2) are respectively provided with retaining rods (903.3), and rolling balls (903.4) are provided at the ends of the retaining rods (903.3), and the rolling balls (903.4) are arranged to roll and engage with the bending guide rods (901). 9. A two-way switching system for a sewage treatment plant according to claim 8.

[0086] (Appendix 10) A hanging rod (905) is provided at the side of the bending guide rod (901), and the diameter of the hanging rod (905) is smaller than that of the bending guide rod (901) and is also smaller than the distance between the two rolling balls (903.4). A semi-annular sliding sleeve (903.2) is provided to slide along the bending guide rod (901), and the hanging rod (905) can pass through the curved opening of the semi-annular sliding sleeve (903.2), and the hanging rod (905) is provided to connect with the support frame. 10. A two-way switching system for a sewage treatment plant according to claim 9,

[0087] (Appendix 11) A counterweight (906) is provided at one end of the hauling net (902), and the hauling net (902) is provided with at least four pull rings (907), which are connected to a towing rope (904), and the towing rope (904) is pulled by mechanical equipment or by human power. The hauling net (902) has four main load straps (902.1), which are surrounded by a rectangular structure, and the four main load straps (902.1) are woven with mesh bags, and the length of the hauling net (902) is greater than the distance between the curved mouths of the U-shaped guide rods. 11. A two-way switching system for a sewage treatment plant according to claim 10.

[0088] (Appendix 12) The liquid level H and sludge concentration C are measured using the liquid level sensor, sludge concentration sensor, and flow rate sensor installed in the inflow groove tank (1). s Step 1: monitoring and collecting the flow velocity V and The time t is the scanning period, and the average liquid level H avg , average sludge concentration C s,avg , and the mean flow velocity V avg Step 2: Calculate Liquid level warning value H0, sludge concentration warning value C s0The warning values ​​including the warning value V0 of the flow rate are preset, and the liquid level is used as the main indicator for determining the rainy season, and the sludge concentration and flow rate are used as secondary indicators. The average liquid level H is calculated based on the following formula: avg , average sludge concentration C s,avg , and the mean flow velocity V avg Step 3: setting the threshold for the rainy season working conditions by performing a weight analysis on X=w H ·(H avg -H0)+w Cs ·(C s,avg -C s,0 )+w V ·(V avg -V0) (where wH, wCs, and wV are the weighting coefficients for the liquid level, sludge concentration, and flow velocity, respectively, and satisfy the equation wH+wCs+wV=1, and X is the overall index.) Step 4: setting a threshold X0 of the comprehensive index for determining the current working conditions; if X>X0, determining that the working conditions are in the rainy season and switching to the rainy season processing system; if X≦X0, determining that the working conditions are not in the rainy season and switching to the dry season processing system; and step 5, if it is determined that it is the dry season, the control unit sends a command to the switching valve (24) to adjust the switching valve (24) to a set position for directing the switching valve (24) to the dry season treatment system, and if it is determined that it is the rainy season, the control unit sends a command to the switching valve (24) to adjust the switching valve (24) to a set position for directing the switching valve (24) to the rainy season treatment system. A method for operating a two-way switching system in a sewage treatment plant according to any one of appendices 1-11.

[0089] (Appendix 13) When there is too much floating matter at the entrance of the self-cleaning grate (13), the emergency floating matter lifting device (9) is activated to lift the floating matter batchwise; The salvage process, All the sliding fasteners (903) are fitted onto one end of the bending guide rod (901), and one end of the hauling net (902) is pulled by the towing rope (904) and slides, and the other end of the hauling net (902) is pulled together with the towing rope (904). When the sliding fasteners (903) at one end of the hauling net (902) reach the other side of the bending guide rod (901) and are pulled, the hauling net (902) is fully unfolded, and the towing ropes (904) connected to both ends of the hauling net (902) are simultaneously lifted up to haul up the floating objects on the surface of the wastewater. After one hauling is completed, the hauling net (902) is similarly positioned below the floating objects, so that the positioning process of the hauling net (902) is not interfered with by the floating objects. 13. The operating method according to claim 12, [Explanation of symbols]

[0090] 1 - inflow channel tank, 2 - fine and coarse mixing grate, 3 - settling tank, 4 - membrane grate device, 5 - AAO combined tank, 6 - MER reaction tank, 7 - first ultraviolet disinfection tank, 8 - first metering pump, 901 - bending guide rod, 902 - hauling net, 902.1 - main load belt, 903 - sliding fastener, 903.1 - rotating seat, 903.2 - semi-annular sliding sleeve, 903.3 - inner fastener rod, 903.4 - rolling ball, 904 - towing rope, 905 - hanging rod, 906 - fishing rod Counterweight, 907-pulling ring, 9-emergency floating matter lifting device, 10-sludge discharge device, 11-centrifuge dewatering machine, 12-sludge pond, 13-self-cleaning grate, 14-flow control valve, 15-combined regulating reservoir, 16-magnetic settling system, 17-fiber rotating disk filter, 18-second ultraviolet disinfection tank, 19-second metering pump, 20-residue discharge device, 21-acid addition device, 22-air aeration device, 23-carbon supply device, 24-switching valve.

Claims

1. The inlet trough tank (1) is connected to the dry season treatment system and the rainy season treatment system, respectively; The dry season treatment system has a fine-coarse mixing grate (2), which is connected in sequence to a settling tank (3), a membrane grate device (4), an AAO combined tank (5), an MER reaction tank (6) and a first ultraviolet disinfection tank (7); The rainy season treatment system has a self-cleaning grate (13), which is connected in series with a flow control valve (14), a combined flow regulation reservoir (15), a magnetic sedimentation system (16), a fiber rotating disk filter (17) and a second ultraviolet disinfection tank (18); The inlet trough tank (1) is provided with a liquid level sensor, a sludge concentration sensor and a flow rate sensor, and a switching valve (24) is provided in front of the self-cleaning grate (13), the liquid level sensor, the sludge concentration sensor and the flow rate sensor are connected to a control unit, and the control unit is used to control the operation of the switching valve (24). A two-way switching system for a sewage treatment plant.

2. The system further includes a sludge treatment system, the sludge treatment system having a sludge tank (12), dewatering the sludge tank (12) using a centrifugal dehydrator (11), a sludge discharge device (10) provided at a sludge discharge outlet of the centrifugal dehydrator (11), and sludge from the MER reaction tank (6) being transported to the sludge tank (12) via the sludge transport device (10).

2. The two-way switching system for a sewage treatment plant according to claim 1.

3. The MER reaction tank (6) is connected to the AAO combined tank (5) through a sludge circulation pipe, and a phosphorus solution circulation pipe is provided between the MER reaction tank (6) and the AAO combined tank (5).

2. The two-way switching system for a sewage treatment plant according to claim 1.

4. The sludge from the magnetic settling system (16) and the fiber rotating disc filter (17) is treated by the centrifugal dewatering machine (11).

3. The two-way switching system for a sewage treatment plant according to claim 2.

5. The MER reaction tank (6) is equipped with an acid addition device (21), and the AAO combined tank (5) is equipped with an aeration device (22) and a carbon supply device (23).

2. The two-way switching system for a sewage treatment plant according to claim 1.

6. A transition passage (25) is provided between the self-cleaning grate (13) and the switching valve (24), and an emergency floating matter lifting device (9) is provided in the transition passage (25), and the emergency floating matter lifting device (9) is used to lift excess floating matter.

2. The two-way switching system for a sewage treatment plant according to claim 1.

7. The emergency floating object salvage device (9) has a curved guide rod (901), a salvage net (902) is arranged between two curved guide rods (901), a sliding fastener (903) is arranged on the salvage net (902), the sliding fastener (903) is arranged to slide along the curved guide rod (901), both ends of the salvage net (902) are used to attach tow ropes (904), the curved guide rods (901) are U-shaped guide rods, the planes on which the two U-shaped guide rods are located are parallel to each other, and the lower half of the U-shaped guide rod is arranged to be submerged in water.

7. The two-way switching system for a sewage treatment plant according to claim 6.

8. The sliding fastener (903) has a rotating seat (903.1), the rotating seat (903.1) is rotatably connected to a semi-annular sliding sleeve (903.2), at least four rotating seats (903.1) are arranged, the four rotating seats (903.1) are respectively attached to the four corners of the hauling net (902), and the semi-annular sliding sleeve (903.2) is arranged to slide on the bending guide rod (901). The two-way switching system for a sewage treatment plant according to claim 7.

9. The arc angle of the semi-annular sliding sleeve (903.2) is in the range of 180-360°, and two ends of the semi-annular sliding sleeve (903.2) are respectively provided with internal retaining rods (903.3), and the ends of the internal retaining rods (903.3) are provided with rolling balls (903.4), which are arranged to roll and engage with the bending guide rod (901). The two-way switching system for a sewage treatment plant according to claim 8.

10. A hanging rod (905) is provided on the side of the bending guide rod (901), and the diameter of the hanging rod (905) is smaller than that of the bending guide rod (901) and is also smaller than the distance between the two rolling balls (903.4). A semi-annular sliding sleeve (903.2) is provided to slide along the bending guide rod (901), and the hanging rod (905) can pass through the curved opening of the semi-annular sliding sleeve (903.2), and the hanging rod (905) is provided to connect with the support frame. The two-way switching system for a sewage treatment plant according to claim 9.

11. A counterweight (906) is provided at one end of the hauling net (902), and the hauling net (902) is provided with at least four pull rings (907), which are connected to a towing rope (904), and the towing rope (904) is pulled by mechanical equipment or by human power. The hauling net (902) has four main load straps (902.1), which are surrounded by a rectangular structure, and mesh bags are attached to the four main load straps (902.1), and the length of the hauling net (902) is greater than the distance between the curved openings of the U-shaped guide rods. The two-way switching system for a sewage treatment plant according to claim 10.

12. The liquid level H and sludge concentration C are measured using a liquid level sensor, a sludge concentration sensor, and a flow rate sensor installed in the inflow groove tank (1). ｓ Step 1 of monitoring and collecting the flow rate V; The time t is the scanning period, and the average liquid level H ａｖｇ , average sludge concentration C ｓ，ａｖｇ , and the mean flow velocity V ａｖｇ Step 2: calculating Liquid level warning value H ０ , sludge concentration warning value C ｓ０ and flow velocity warning value V ０ The liquid level is used as the main indicator for determining the rainy season, and the sludge concentration and flow rate are used as secondary indicators. The average liquid level H is calculated based on the following formula: ａｖｇ , average sludge concentration C ｓ，ａｖｇ , and the mean flow velocity V ａｖｇ Step 3: setting a threshold value for the rainy season working conditions by performing a weight analysis on X=w Ｈ ・(H ａｖｇ -H ０ )+w Ｃｓ ・(C ｓ，ａｖｇ -C ｓ，０ )+w Ｖ ・(V ａｖｇ -V ０ ) (WH, WCS, and WV are weighting coefficients for the liquid level, sludge concentration, and flow rate, respectively, and satisfy the equation WH + WCS + WV = 1, and X is the overall index.) Step 4: setting a threshold X0 of a comprehensive index for determining the current working conditions, if X>X0, determining that the working conditions are those of the rainy season and switching to the rainy season processing system, if X≦X0, determining that the working conditions are not those of the rainy season and switching to the dry season processing system; and step 5, if it is determined that it is the dry season, the control unit sends a command to the switching valve (24) to adjust the switching valve (24) to a set position for directing the switching valve (24) to the dry season treatment system, and if it is determined that it is the rainy season, the control unit sends a command to the switching valve (24) to adjust the switching valve (24) to a set position for directing the switching valve (24) to the rainy season treatment system. A method for operating a two-way switching system in a sewage treatment plant according to any one of claims 1 to 11.

13. When there is too much floating matter at the entrance of the self-cleaning grate (13), the emergency floating matter lifting device (9) is activated to lift the floating matter in batches; The salvage process, All the sliding fasteners (903) are fitted onto one end of the bending guide rod (901), and one end of the hauling net (902) is pulled and slid by the towing rope (904), and the other end of the hauling net (902) is pulled together with the towing rope (904). When the sliding fasteners (903) at one end of the hauling net (902) reach the other side of the bending guide rod (901) and are pulled, the hauling net (902) is fully deployed, and the towing ropes (904) connected to both ends of the hauling net (902) are simultaneously lifted up to haul up the floating objects on the surface of the wastewater. After one hauling is completed, the hauling net (902) is similarly positioned below the floating objects, so that the positioning process of the hauling net (902) is not interfered with by the floating objects.

13. The method of claim 12.

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