Dual-channel switching system for wastewater treatment plant, and operation method

Abstract

A dual-channel switching system for a wastewater treatment plant, and an operation method. The double-channel switching system comprises a water intake box culvert in communication with both a dry-season treatment system and a rainy-season treatment system, wherein the dry-season treatment system comprises a coarse-fine combined screen connected to a grit chamber, a membrane screen device, an AAO combined tank, an MER reaction tank and a first ultraviolet disinfection channel in sequence; the rainy-season treatment system comprises a self-cleaning screen connected to a flow control valve, a combined storage tank, a magnetic precipitation system, a fiber rotary disc filter and a second ultraviolet disinfection channel in sequence; the water intake box culvert is provided with a liquid level sensor, a sludge concentration sensor, and a flow rate sensor; a switching valve is provided at the front end of the self-cleaning screen; and the liquid level sensor, the sludge concentration sensor and the flow rate sensor are connected to a control unit In the present invention, a wastewater treatment path can be automatically adjusted on the basis of changes in seasons and water volumes, thereby effectively meeting wastewater treatment requirements in a dry season and a rainy season.

Description

A dual-channel switching system and operation method for a sewage treatment plant Technical Field

[0001] The present invention belongs to the technical field of sewage treatment, and in particular relates to a dual-channel switching system and an operating method for a sewage treatment plant. Background Art

[0002] In the field of wastewater treatment, designing and implementing effective treatment strategies tailored to the characteristics of wastewater under different seasonal and climatic conditions is crucial. This is especially true during the rainy season, when large amounts of rainwater enter the wastewater treatment system, creating challenges with high flow rates and suspended solids concentrations, placing higher demands on the normal operation of wastewater treatment plants. Traditional wastewater treatment systems often lack the ability to automatically adjust treatment pathways based on seasonal variations. During the rainy season, the influx of rainwater causes a sharp increase in suspended solids and impurity concentrations in wastewater. A single treatment process is unable to cope with this high load, potentially leading to reduced treatment efficiency or even exceeding treatment capacity, causing environmental pollution. In the dry season, wastewater volumes are relatively low, but pollutant concentrations are higher, requiring more sophisticated treatment methods. Consequently, existing systems are limited in flexibility and adaptability. Therefore, a dual-channel switching system for wastewater treatment plants is urgently needed. This system can automatically select the most appropriate treatment pathway based on seasonal wastewater characteristics to optimize treatment efficiency and costs.

[0003] Furthermore, during the rainy season, large amounts of rainwater carry floating debris such as leaves, plastic bags, and foam into the treatment system, potentially clogging water inlets, self-cleaning screens, and other key equipment, seriously impacting water treatment efficiency and quality. Currently, the main methods for dealing with floating debris include manual cleaning and the use of simple salvage tools such as nets or long-handled scoops. However, these traditional methods have significant limitations, such as low efficiency, high labor intensity, poor safety, and difficulty in quickly responding to and handling dense floating debris.

[0004] Summary of the Invention

[0005] The technical problem to be solved by this invention is to provide a dual-channel switching system and operating method for sewage treatment plants. This system, comprising a dry season treatment system and a rainy season treatment system, automatically selects the most appropriate treatment path by real-time monitoring of the liquid level, sludge concentration, and flow rate in the inlet culvert, combined with intelligent control. This system automatically adapts to seasonal sewage characteristics, significantly improving the sewage treatment plant's operating efficiency and environmental adaptability. This system not only addresses the limitations of traditional sewage treatment processes but also provides an innovative solution for more economical and environmentally friendly sewage treatment.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A dual-channel switching system for a sewage treatment plant includes an inlet culvert connected to a dry season treatment system and a rainy season treatment system;

[0008] The dry season treatment system includes a coarse and fine combined grid, which is sequentially connected to a grit chamber, a membrane grid device, an AAO combined tank, a MER reaction tank and a first ultraviolet disinfection channel;

[0009] The rainy season treatment system includes a self-cleaning grille, which is sequentially connected to a flow regulating valve, a combined flow storage tank, a magnetic precipitation system, a fiber rotary disc filter and a second ultraviolet disinfection channel;

[0010] The water inlet culvert is equipped with a liquid level sensor, a sludge concentration sensor and a flow rate sensor. The front end of the self-cleaning grille is provided with a switching valve. The liquid level sensor, sludge concentration sensor and flow rate sensor are connected to the control unit, which is used to control the action of the switching valve.

[0011] Preferably, it also includes a sludge treatment system, which includes a sludge pool. The sludge pool is dehydrated by a centrifugal dehydrator, and the sludge outlet of the centrifugal dehydrator is provided with a sludge transport device; the sludge in the MER reaction tank is transported to the sludge pool through the sludge transport device.

[0012] Preferably, the MER reaction tank is connected to the AAO combination tank through a sludge return pipe; a phosphating liquid return pipe is provided between the MER reaction tank and the AAO combination tank.

[0013] Preferably, the sludge from the magnetic precipitation system and the fiber disc filter is processed by a centrifugal dewatering machine.

[0014] Preferably, the MER reaction tank is equipped with an acid adding device; the AAO combination tank is equipped with an aeration device and a carbon supply device.

[0015] Preferably, a transition channel is provided between the self-cleaning grille and the switching valve, and a floating object emergency salvage device is provided in the transition channel; the floating object emergency salvage device is used to salvage excess floating objects.

[0016] Preferably, it includes a curved guide rod, a salvage net is provided between the two curved guide rods, and a sliding buckle is provided on the salvage net, which is used to slide along the curved guide rod; both ends of the salvage net are used to install a traction rope; the curved guide rod is a U-shaped guide rod, and the planes where the two U-shaped guide rods are located are parallel to each other; the lower half of the U-shaped guide rod is used to sink underwater.

[0017] Preferably, the sliding buckle includes a rotating seat, which is rotatably connected to a semi-annular sliding sleeve; there are at least four rotating seats, which are respectively installed at the four corners of the fishing net, and the semi-annular sliding sleeve is used to slide on the curved guide rod;

[0018] The arc range of the semi-annular sliding sleeve is 180°-360°. The two ends of the semi-annular sliding sleeve are respectively provided with inner rods. The ends of the inner rods are provided with balls. The balls are used for rolling cooperation with the curved guide rod.

[0019] Preferably, a suspension rod is provided on the side of the curved guide rod, wherein the diameter of the suspension rod is smaller than the diameter of the curved guide rod, and the diameter of the suspension rod is smaller than the distance between the two balls. The semi-annular sliding sleeve is used to slide along the curved guide rod, and the opening of the semi-annular sliding sleeve can pass through the suspension rod. The suspension rod is used to connect to the support frame.

[0020] A counterweight pendant is provided at one end of the salvage net; the salvage net is provided with at least four pull rings, which are connected to the traction rope, and the traction rope is pulled by mechanical equipment or manually; the salvage net includes four main load-bearing belts. The four main load-bearing belts form a rectangular structure, and the four main load-bearing belts are woven with net bags; the length of the salvage net is greater than the opening width of the U-shaped guide rod.

[0021] A method for operating a dual-channel switching system for a sewage treatment plant comprises the following steps:

[0022] Step 1: Use the liquid level sensor, sludge concentration sensor and flow rate sensor in the water inlet culvert to monitor and collect the liquid level height H, sludge concentration Cs and flow rate V in real time;

[0023] The unit of liquid level height is meter (m);

[0024] The unit of sludge concentration is milligrams per liter (mg / L);

[0025] The unit of flow velocity is meter per second (m / s);

[0026] Step 2: Take time t as the scanning period and calculate the average liquid level H in one period avg , average sludge concentration C s,avg , average flow velocity V avg ;

[0027] Step 3: Set the rainy season threshold:

[0028] ① Warning values ​​include: liquid level warning value H0, sludge concentration warning value Cs0, flow rate warning value V0;

[0029] ② Liquid level height is the main indicator for judging the rainy season, while sludge concentration and flow rate are secondary indicators;

[0030] ③ Average liquid level H avg , average sludge concentration Cs ,avg , average flow velocity V avg Perform weight analysis, the formula is:

[0031]

[0032] wH, wCs, and wV are weight coefficients of liquid level, sludge concentration, and flow rate, respectively, and wH+wCs+wV=1; X is a comprehensive index;

[0033] Step 4: Set the threshold value X0 of the comprehensive index to judge the current working condition:

[0034] If X>X0, it is judged as rainy season condition and switched to rainy season processing system;

[0035] If X≤X0, it is judged as a non-rainy season condition and switched to the dry season processing system;

[0036] Step 5: If it is determined to be a dry season, the control unit sends an instruction to the switching valve to adjust it to a position pointing to the dry season treatment system;

[0037] If it is determined to be the rainy season, the control unit sends an instruction to the switching valve to adjust it to a position pointing to the rainy season treatment system.

[0038] Preferably, when there are too many floating objects at the inlet of the self-cleaning grille, the floating object emergency salvage device is activated to salvage the floating objects in batches; the salvage process is as follows:

[0039] All the sliding buckles are uniformly sleeved on the bending guide rod from one end;

[0040] Then one end of the salvage net is pulled and slid by the traction rope, and the other end of the salvage net is pulled in coordination with the traction rope;

[0041] When the sliding buckle at one end of the salvage net is pulled to the other end of the curved guide rod, the salvage net is fully deployed;

[0042] At the same time, lift the traction ropes at both ends of the salvage net to salvage the floating objects on the surface of the sewage;

[0043] After one salvage operation is completed, the salvage net is laid out under the floating object using the same method, and the laying of the salvage net will not be disturbed by the floating object.

[0044] The present invention can achieve the following beneficial effects:

[0045] The dry season and rainy season treatment systems of this invention automatically select the most appropriate treatment path by real-time monitoring of the liquid level, sludge concentration, and flow rate in the inlet culvert, combined with intelligent control. This system automatically adapts to seasonal sewage characteristics, significantly improving the operational efficiency and environmental adaptability of the sewage treatment plant. This system not only overcomes the limitations of traditional sewage treatment processes but also provides an innovative solution for more economical and environmentally friendly sewage treatment.

[0046] The present invention can automatically adjust the sewage treatment path according to seasonal and water volume changes, effectively responding to sewage treatment needs in dry and rainy seasons. At the same time, the integrated floating object emergency salvage device improves the system's emergency treatment capabilities and maintenance efficiency, and overall enhances the operating efficiency and flexibility of the sewage treatment plant.

[0047] The floating debris emergency salvage device combines a flexible curved guide rod, an expandable salvage net and an adaptive sliding buckle design. It can quickly and effectively collect and clear floating debris on the water surface without interrupting the water treatment process, significantly improving the operating efficiency and safety of sewage treatment plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The present invention will be further described below with reference to the accompanying drawings and examples:

[0049] FIG1 is a process flow chart of the present invention;

[0050] Figure 2 is a three-dimensional structural diagram of the floating object emergency salvage device;

[0051] Figure 3 is an enlarged view of point A in Figure 2;

[0052] FIG4 is a side view of the floating object emergency salvage device (in use state 1);

[0053] Figure 5 is a side view of the floating object emergency salvage device (use status 2);

[0054] Figure 6 is a structural diagram of the connection between the salvage net and the sliding buckle of the floating object emergency salvage device;

[0055] Figure 7 is a top view of the floating object emergency salvage device;

[0056] Figure 8 is a diagram showing the installation location of the floating object emergency salvage device.

[0057] Figure: Inlet culvert 1, coarse and fine combination screen 2, grit chamber 3, membrane screen device 4, AAO combination tank 5, MER reaction tank 6, first UV disinfection channel 7, first metering pump 8, curved guide rod 901, fishing net 902, main load-bearing belt 902.1, sliding buckle 903, rotating seat 903.1, semi-annular sliding sleeve 903.2, inner buckle rod 903.3, ball bearing 903.4, traction rope 904, boom 905, counterweight Pendant 906, pull ring 907, floating object emergency salvage device 9, sludge transport device 10, centrifugal dewatering machine 11, sludge tank 12, self-cleaning screen 13, flow regulating valve 14, combined flow storage tank 15, magnetic precipitation system 16, fiber rotary disc filter 17, second ultraviolet disinfection channel 18, second metering pump 19, waste residue discharge device 20, acid adding device 21, aeration device 22, carbon supply device 23, control switching valve 24. DETAILED DESCRIPTION

[0058] The preferred solution is shown in Figures 1 to 8 , which is a dual-channel switching system for a sewage treatment plant, including an inlet culvert 1 , which is connected to a dry season treatment system and a rainy season treatment system respectively;

[0059] The dry season treatment system includes a coarse and fine combination grid 2, which is connected in sequence to a grit chamber 3, a membrane grid device 4, an AAO combination tank 5, a MER reaction tank 6 and a first ultraviolet disinfection channel 7; the waste residue of the coarse and fine combination grid 2 is discharged by a waste residue discharge device 20, which is an auger conveyor or the like.

[0060] The rainy season treatment system includes a self-cleaning grille 13, which is sequentially connected to a flow regulating valve 14, a combined flow storage tank 15, a magnetic precipitation system 16, a fiber rotary disk filter 17 and a second ultraviolet disinfection channel 18;

[0061] The water inlet culvert 1 is provided with a liquid level sensor, a sludge concentration sensor and a flow rate sensor. The front end of the self-cleaning grille 13 is provided with a switching valve 24. The liquid level sensor, sludge concentration sensor and flow rate sensor are connected to the control unit, which is used to control the action of the switching valve 24.

[0062] The inlet culvert 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 coarse-fine combination screen 2, a grit chamber 3, a membrane screen device 4, an AAO combination tank 5, a MER reaction tank 6, and a first UV disinfection channel 7. The wet season treatment system includes a self-cleaning screen 13, a flow regulating valve 14, a combined sewer storage tank 15, a magnetic precipitation system 16, a fiber rotary disc filter 17, and a second UV disinfection channel 18. The dry season treatment system and the wet season treatment system are switched via a switching valve 24, located at the front end of the self-cleaning screen 13. The control unit automatically opens or closes the valve based on the liquid level, sludge concentration, and flow rate sensor signals within the inlet culvert 1, switching between the dry and wet season treatment paths. The control unit can be a Siemens SIMATIC S7 series PLC, suitable for automation tasks ranging from small to large.

[0063] Furthermore, the system also includes a sludge treatment system, which includes a sludge tank 12. The sludge tank 12 is dehydrated by a centrifugal dehydrator 11, and a sludge transport device 10 is provided at the sludge outlet of the centrifugal dehydrator 11; the sludge in the MER reaction tank 6 is transported to the sludge tank 12 through the sludge transport device.

[0064] The sludge treatment system includes a sludge tank 12, which is dehydrated by a centrifugal dewatering machine 11. A sludge transport device 10 is installed at the sludge discharge port. Sludge from the MER reaction tank 6 is transported to the sludge tank 12 via a sludge conveyor. Sludge from the magnetic precipitation system 16 and the fiber rotary disc filter 17 is also treated by the centrifugal dewatering machine 11.

[0065] Furthermore, the MER reaction tank 6 is connected to the AAO combination tank 5 through a sludge return pipe; a phosphating liquid return pipe is provided between the MER reaction tank 6 and the AAO combination tank 5.

[0066] The MER reaction tank 6 is connected to the AAO combination tank 5 through a sludge return pipe, and a phosphating liquid return pipe is additionally provided.

[0067] Furthermore, the sludge from the magnetic precipitation system 16 and the fiber rotary disc filter 17 is processed by the centrifugal dewatering machine 11 .

[0068] Furthermore, the MER reaction tank 6 is equipped with an acid adding device 21 ; the AAO combination tank 5 is equipped with an aeration device 22 and a carbon supply device 23 .

[0069] The MER reaction tank 6 is equipped with an acid adding device 21 , and the AAO combination tank 5 is equipped with an aeration device 22 and a carbon supply device 23 .

[0070] Furthermore, a transition channel 25 is provided between the self-cleaning grid 13 and the switching valve 24 , and a floating object emergency salvaging device 9 is provided in the transition channel 25 ; the floating object emergency salvaging device 9 is used to salvage excess floating objects.

[0071] A transition channel 25 is provided between the self-cleaning grille 13 and the switching valve 24, with a built-in floating object emergency salvage device 9, including components such as a bent guide rod 901, a salvage net 902, a sliding buckle 903, and a traction rope 904, for dealing with situations where there are too many floating objects.

[0072] It includes a curved guide rod 901, a salvage net 902 is provided between the two curved guide rods 901, and a sliding buckle 903 is provided on the salvage net 902. The sliding buckle 903 is used to slide along the curved guide rod 901; the two ends of the salvage net 902 are used to install a traction rope 904.

[0073] The curved guide rod 901 can be shaped like an arc or a semicircular rod. The lower half of the curved guide rod 901 is designed to sink into the water, and the sliding buckles 903 are designed to be attached to the curved guide rod 901. During use, all the sliding buckles 903 are uniformly attached to the curved guide rod 901 from one end. Then, one end of the salvage net 902 is pulled and slid by the traction rope 904, while the other end of the salvage net 902 is pulled in tandem by the traction rope 904. When the sliding buckle 903 at one end of the salvage net 902 is pulled to the other end of the curved guide rod 901, the salvage net 902 is fully deployed. If there are too many floating objects on the sewage surface, the traction ropes 904 at both ends of the salvage net 902 are simultaneously lifted to salvage the floating objects. After salvaging is complete, the salvage net 902 is deployed again using the same method below the floating objects, and the deployment of the salvage net 902 is not disturbed by the floating objects.

[0074] Furthermore, the bent guide rod 901 in this embodiment is a U-shaped guide rod, and the planes where the two U-shaped guide rods are located are parallel to each other; the lower half of the U-shaped guide rod is used to sink underwater.

[0075] The salvage net 902 is positioned between the two U-shaped guide rods. Its length is greater than the width of the openings of the U-shaped guide rods, and its width is slightly greater than the distance between the two U-shaped guide rods. FIG1 shows the salvage net 902 in a taut state. However, in actual use, the salvage net 902 is preferably equipped with a concave net bag to facilitate the salvage of more floating objects at a time.

[0076] Furthermore, the sliding buckle 903 includes a rotating seat 903.1, which is rotatably connected to a semi-annular sliding sleeve 903.2; there are at least four rotating seats 903.1, and the four rotating seats 903.1 are respectively installed at the four corners of the salvage net 902, and the semi-annular sliding sleeve 903.2 is used to slide on the curved guide rod 901.

[0077] The semi-annular sliding sleeve 903.2 is rotatably coupled to the rotating base 903.1 and is configured to be sleeved onto the curved guide rod 901. The semi-annular sliding sleeve 903.2 can adaptively rotate as the orientation of the salvage net 902 changes. The rotating base 903.1 and the salvage net 902 can be connected using a snap-fit ​​connection or a tethered connection.

[0078] Furthermore, the arc range of the semi-annular sleeve 903.2 is 180°-360°, and the two ends of the semi-annular sleeve 903.2 are respectively provided with inner rods 903.3, and the ends of the inner rods 903.3 are provided with balls 903.4, which are used to roll with the curved guide rod 901.

[0079] The ball bearings 903.4 are used to reduce the resistance between the sliding buckle 903 and the curved guide rod 901, so as to facilitate the sliding buckle 903 to slide smoothly on the curved guide rod 901.

[0080] Furthermore, a hanger 905 is provided on the side of the bent guide rod 901, the diameter of the hanger 905 is smaller than the diameter of the bent guide rod 901, and the diameter of the hanger 905 is smaller than the distance between the two balls 903.4; the semi-annular sleeve 903.2 is used to slide along the bent guide rod 901, and the opening of the semi-annular sleeve 903.2 can pass through the hanger 905; the hanger 905 is used to connect the support frame.

[0081] The support frame suspends the two curved guide rods 901 in the water via a boom 905. The curved guide rods 901 are not completely submerged, allowing the sliding buckle 903 to smoothly move from one end of the curved guide rod 901 to the other. To prevent interference between the boom 905 and the sliding buckle 903, the floating object emergency salvage device refines the structure of the sliding buckle 903. Specifically, the semi-annular sliding sleeve 903.2 is not fully closed, and the two ball bearings 903.4 maintain sufficient spacing to pass through the boom 905. The boom 905 has a smaller diameter than the curved guide rod 901 and is L-shaped. This allows the sliding buckle 903 to pass through the boom 905 without detaching from the curved guide rod 901. When it is necessary to salvage floating objects, the salvage net 902 can be completely removed from the curved guide rod 901.

[0082] Furthermore, a counterweight pendant 906 is provided at one end of the salvage net 902 .

[0083] When the salvage net 902 is installed on the curved guide rod 901, the counterweight pendant 906 can provide a downward pulling force, which can smoothly pull one end of the salvage net 902 downward.

[0084] Furthermore, the salvage net 902 is provided with at least four pull rings 907 , and the pull rings 907 are connected to the traction rope 904 , and the traction rope 904 is pulled by mechanical equipment or manually.

[0085] This device is an emergency device and is used less frequently. It can be used when there are too many floating objects and the self-cleaning grille cannot handle the large amount of floating objects in a short time. The traction method can be manual traction. If manpower is insufficient to clear the floating objects, a winch can be used to pull the traction rope 904.

[0086] Furthermore, the salvage net 902 includes four main load-bearing belts 902.1, which form a rectangular structure. Net bags are woven on the four main load-bearing belts 902.1; the length of the salvage net 902 is greater than the opening width of the U-shaped guide rod.

[0087] The four main load-bearing belts 902.1 can be made of nylon belts to ensure sufficient mechanical strength while also having a certain degree of flexibility.

[0088] This device is used in front of a self-cleaning screen. Some wastewater treatment plants utilize two treatment processes: dry season and rainy season. The rainy season refers to the period of abundant rainfall. During the rainy season, when water levels rise, a large amount of floating debris is generated. The entrance to the rainy season treatment process passes through the self-cleaning screen. When the self-cleaning screen is unable to quickly clear a large amount of floating debris, this device can be used as an emergency measure.

[0089] The functions of other devices in this system are as follows:

[0090] The self-cleaning screen is a pre-treatment equipment used at the front end of the water treatment system. Its main function is to intercept and remove larger suspended matter, floating matter and solid particles in the water to protect subsequent water treatment equipment from damage. The design of the self-cleaning screen enables it to automatically remove dirt accumulated on the screen during operation without downtime or manual intervention, thereby ensuring continuous and stable water flow and system operation efficiency. The following is the working principle of the self-cleaning screen: including a screen frame: used to support and fix the screen plate, usually made of corrosion-resistant materials such as stainless steel or fiberglass. Screen plate: composed of a series of parallel bars, and the gap between the bars is designed according to the size of the solid particles that need to be intercepted. Cleaning device: including a drive mechanism, cleaning brushes or rake teeth, control device, etc., used to remove dirt from the screen plate.

[0091] The AAO (Anaerobic-Anoxic-Oxic) combined tank, also known as the A2O (Anaerobic-Anoxic-Oxic) tank, is a biological treatment process widely used in wastewater treatment, primarily for nitrogen and phosphorus removal. This process combines anaerobic, anoxic, and aerobic environments to efficiently remove organic matter, nitrogen, and phosphorus from wastewater. The detailed working principle and components of the AAO combined tank are as follows: 1. Anaerobic stage: Releases phosphorus and ammonifies some organic matter. Under anaerobic conditions, phosphate-accumulating bacteria release stored phosphates and decompose some organic matter, facilitating phosphorus absorption in the subsequent aerobic stage. 2. Anoxic stage: Denitrification reduces nitrates to nitrogen gas. In anoxic conditions, denitrifying bacteria use organic matter as electron donors to reduce nitrates to nitrogen gas, thereby removing nitrogen. 3. Aerobic stage: Oxidation of organic matter, nitrification, and phosphorus absorption. In an aerobic environment, aerobic microorganisms oxidize organic matter into carbon dioxide and water, while nitrifying bacteria convert ammonia nitrogen into nitrite and nitrate. During this stage, phosphate-accumulating bacteria reabsorb phosphorus and store it within their cells.

[0092] The MBR (Membrane Bioreactor) reactor, or membrane bioreactor, is a highly efficient wastewater treatment system that combines biological treatment technology with membrane separation technology. The core of the MBR system lies in the use of membrane modules for solid-liquid separation, replacing traditional secondary sedimentation tanks. This allows the activated sludge concentration in the biological treatment unit to be maintained at a high level, thereby improving biochemical treatment efficiency and effluent quality. The activated sludge (microorganisms) in the MBR reactor decompose organic matter and some inorganic matter in the water under aerobic or anaerobic conditions, undergoing biodegradation and conversion, producing carbon dioxide, water, and new biomass. Microbial growth and metabolic activity continue continuously within the MBR, forming high concentrations of biofilm and suspended activated sludge. Submerged or external membrane modules are used in MBR reactors. These modules can be flat sheet membranes, tubular membranes, or hollow fiber membranes. Through filtration, the membrane modules retain activated sludge and suspended solids, allowing only clear water to pass through, thus achieving solid-liquid separation. After membrane filtration, the clear water (permeate) is clear and has extremely low suspended solids content, allowing it to be directly discharged or reused.

[0093] A fiber disc filter is a highly efficient water treatment device commonly used in the advanced treatment stage of sewage treatment plants. It removes suspended solids, microorganisms, and some dissolved organic matter from water to meet discharge standards or reuse water quality requirements. Its primary functions include filtration, biodegradation, and disinfection. It is particularly suitable for removing suspended solids, turbidity, color, and some pathogens from wastewater. The core component of a fiber disc filter is the fiber disc, typically composed of a large number of elongated fiber bundles. These bundles are affixed to the disc, which is mounted in the filter tank via a central axis and can rotate slowly. When wastewater to be treated enters the filter, the water flows through the gaps between the fiber bundles. The fiber bundles have a very large surface area, which can capture suspended solids and colloids in the water, achieving a filtering effect. Due to the unique structure of the fiber bundles, turbulence forms as the water flows through, helping to improve filtration efficiency and prevent clogging of the fiber bundles.

[0094] Magnetic precipitation is a highly effective water treatment technology used to remove suspended solids, colloids, certain soluble substances, and microorganisms from water. It enhances the sedimentation effect by adding magnetic particles (usually magnetic powder) to the conventional coagulation and flocculation processes, resulting in faster and more thorough water purification. The basic working principle of a magnetic precipitation system is that magnetic particles are added during the coagulation and flocculation processes. These magnetic particles bind to suspended solids and flocs in the water, forming so-called "magnetic flocs." Because the specific gravity of the magnetic particles is much higher than that of water, the settling rate of the magnetic flocs is significantly accelerated. The system works as follows: First, a coagulant (such as polyaluminum chloride (PAC)) and a flocculant (such as polyacrylamide (PAM)) are added to the water to be treated to promote the aggregation of suspended solids and colloids into larger flocs. During the flocculation process, magnetic particles (magnetic powder) are added and bind to the flocs, forming magnetic flocs. Due to their increased specific gravity, the magnetic flocs settle in the sedimentation tank at a much faster rate than conventional flocs, typically within a few hours, while conventional sedimentation may take several days. After settling, the magnetic flocs are separated by magnetic separation technology (e.g., a magnetic drum) to recover the magnetic powder, which can be recycled, reducing reagent consumption. The supernatant (water from which most suspended matter has been removed) is collected and sent to the next stage of treatment, such as disinfection or advanced treatment.

[0095] Combined sewerage storage tanks are primarily used to treat and control the mixed flow of rainwater and sewage from combined sewer systems. In a combined sewer system, stormwater runoff and domestic or industrial wastewater share a common piping system. This system works well on sunny days, but during heavy rainfall, the combined flow of rainwater and sewage can exceed the sewage treatment plant's processing capacity, leading to the discharge of untreated sewage into water bodies and environmental pollution. To address this issue, combined sewerage storage tanks are designed to store this excess mixed flow until the weather improves, at which time it can be gradually treated and discharged. The operating principle is as follows: When rainfall begins, stormwater runoff and sewage flow through the combined sewer system into the storage tank. During the initial rainfall, the rainwater in the mixed flow (primary rainwater) contains higher concentrations of pollutants, and this water is collected first. When the volume of the mixed flow exceeds the sewage treatment plant's processing capacity, the storage tank begins to store the excess water. The storage tank's capacity is generally designed to be sufficient to handle rainfall events of a certain intensity, preventing the mixed flow from being discharged untreated. After the rainfall ends, the mixed flow in the storage tank is gradually transferred to the sewage treatment plant for treatment through pumping stations or gravity. This process is usually controlled to ensure that the sewage treatment plant is not overloaded again.

[0096] A method for operating a dual-channel switching system for a sewage treatment plant, characterized by:

[0097] Step 1: Use the liquid level sensor, sludge concentration sensor and flow rate sensor in the water inlet culvert 1 to monitor and collect the liquid level height H, sludge concentration Cs and flow rate V in real time;

[0098] The unit of liquid level height is meter (m);

[0099] The unit of sludge concentration is milligrams per liter (mg / L);

[0100] The unit of flow velocity is meter per second (m / s);

[0101] Step 2: Take time t as the scanning period and calculate the average liquid level H in one period avg , average sludge concentration C s,avg , average flow velocity V avg ;

[0102] Step 3: Set the rainy season threshold:

[0103] ① Warning values ​​include: liquid level warning value H0, sludge concentration warning value Cs0, flow rate warning value V0;

[0104] ② Liquid level height is the main indicator for judging the rainy season, while sludge concentration and flow rate are secondary indicators;

[0105] ③ Average liquid level H avg , average sludge concentration Cs ,avg , average flow velocity V avg Perform weight analysis, the formula is:

[0106]

[0107] wH, wCs, and wV are weight coefficients of liquid level, sludge concentration, and flow rate, respectively, and wH+wCs+wV=1; X is a comprehensive index;

[0108] Step 4: Set the threshold value X0 of the comprehensive index to judge the current working condition:

[0109] If X>X0, it is judged as rainy season condition and switched to rainy season processing system;

[0110] If X≤X0, it is judged as a non-rainy season condition and switched to the dry season processing system;

[0111] Step 5: If it is determined to be a dry season, the control unit sends an instruction to the switching valve 24 to adjust it to a position pointing to the dry season treatment system;

[0112] If it is determined to be the rainy season, the control unit sends an instruction to the switching valve 24 to adjust it to a position pointing to the rainy season processing system.

[0113] When there are too many floating objects at the entrance of the self-cleaning grid 13, the floating object emergency salvage device 9 is activated to salvage the floating objects in batches; the salvage process is as follows:

[0114] All the sliding buckles 903 are uniformly sleeved on the curved guide rod 901 from one end thereof;

[0115] Then one end of the salvage net 902 is pulled and slid by the traction rope 904, and the other end of the salvage net 902 is pulled cooperatively by the traction rope 904;

[0116] When the sliding buckle 903 at one end of the salvage net 902 is pulled to the other end of the curved guide rod 901, the salvage net 902 is fully deployed;

[0117] At the same time, lift the traction ropes 904 at both ends of the salvage net 902 to salvage floating objects on the surface of the sewage;

[0118] After salvaging is completed once, the salvage net 902 is deployed under the floating object using the same method. The deployment of the salvage net 902 will not be disturbed by the floating object.

[0119] The above embodiments are merely preferred technical solutions of the present invention and should not be construed as limiting the present invention. The scope of protection of the present invention shall be the technical solutions set forth in the claims, including equivalent alternatives to the technical features of the technical solutions set forth in the claims. In other words, equivalent alternatives and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A dual-channel switching system for a sewage treatment plant, characterized in that: It comprises a water inlet culvert (1), and the water inlet culvert (1) is connected to a dry season treatment system and a rainy season treatment system respectively; The dry season treatment system comprises a coarse and fine combined grid (2), wherein the coarse and fine combined grid (2) is sequentially connected to a grit chamber (3), a membrane grid device (4), an AAO combined tank (5), a MER reaction tank (6) and a first ultraviolet disinfection channel (7); The rainy season treatment system comprises a self-cleaning grille (13), which is sequentially connected to a flow regulating valve (14), a combined flow regulating reservoir (15), a magnetic precipitation system (16), a fiber rotary disc filter (17) and a second ultraviolet disinfection channel (18); The water inlet culvert (1) is provided with a liquid level sensor, a sludge concentration sensor and a flow rate sensor, the front end of the self-cleaning grille (13) is provided with a switching valve (24), 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 action of the switching valve (24).

2. The dual-channel switching system for a sewage treatment plant according to claim 1, wherein: The invention also comprises a sludge treatment system, which comprises a sludge pool (12). The sludge pool (12) is dehydrated by a centrifugal dehydrator (11). The sludge discharge port of the centrifugal dehydrator (11) is provided with a sludge transport device (10). The sludge in the MER reaction pool (6) is transported to the sludge pool (12) by the sludge transport device.

3. A dual-channel switching system for a sewage treatment plant according to claim 1, characterized in that: The MER reaction tank (6) is connected to the AAO combination tank (5) via a sludge return pipe; a phosphating liquid return pipe is provided between the MER reaction tank (6) and the AAO combination tank (5).

4. A dual-channel switching system for a sewage treatment plant according to claim 2, characterized in that: The sludge from the magnetic precipitation system (16) and the fiber disc filter (17) is processed by a centrifugal dewatering machine (11).

5. A dual-channel switching system for a sewage treatment plant according to claim 1, characterized in that: The MER reaction tank (6) is equipped with an acid adding device (21); the AAO combination tank (5) is equipped with an air aeration device (22) and a carbon supply device (23).

6. The dual-channel switching system for a sewage treatment plant according to claim 1, wherein: A transition channel (25) is provided between the self-cleaning grid (13) and the switching valve (24), and a floating object emergency salvage device (9) is provided in the transition channel (25); the floating object emergency salvage device (9) is used to salvage excess floating objects.

7. A dual-channel switching system for a sewage treatment plant according to claim 6, characterized in that: The floating object emergency salvage device (9) comprises a curved guide rod (901), a salvage net (902) is arranged between two curved guide rods (901), a sliding buckle (903) is arranged on the salvage net (902), and the sliding buckle (903) is used to slide along the curved guide rod (901); both ends of the salvage net (902) are used to install a traction rope (904); the curved guide rod (901) is a U-shaped guide rod, and the planes where the two U-shaped guide rods are located are parallel to each other; the lower half of the U-shaped guide rod is used to sink underwater.

8. A dual-channel switching system for a sewage treatment plant according to claim 7, characterized in that: The sliding buckle (903) comprises a rotating seat (903.1), and the rotating seat (903.1) is rotatably connected to a semi-annular sliding sleeve (903.2); there are at least four rotating seats (903.1), and the four rotating seats (903.1) are respectively installed at four corners of the fishing net (902), and the semi-annular sliding sleeve (903.2) is used to slide on the curved guide rod (901).

9. A dual-channel switching system for a sewage treatment plant according to claim 8, characterized in that: The arc range of the semi-circular sliding sleeve (903.2) is 180° - 360°. Inner buckling rods (903.3) are respectively arranged at two ends of the semi-circular sliding sleeve (903.2). Ball bearings (903.4) are arranged at the ends of the inner buckling rods (903.3), and the ball bearings (903.4) are used for rolling cooperation with the curved guide rod (901).

10. A dual-channel switching system for a sewage treatment plant according to claim 9, characterized in that: A suspension rod (905) is arranged on the side of the curved guide rod (901). The diameter of the suspension rod (905) is smaller than that of the curved guide rod (901), and the diameter of the suspension rod (905) is smaller than the distance between two ball bearings (903.4). The semi-circular sliding sleeve (903.2) is used for sliding along the curved guide rod (901), and the opening of the semi-circular sliding sleeve (903.2) can pass through the suspension rod (905). The suspension rod (905) is used for connecting the support frame.

11. A dual-channel switching system for a sewage treatment plant according to claim 10, characterized in that: One end of the fishing net (902) is provided with a counterweight pendant (906). The fishing net (902) is provided with at least four pull rings (907). The pull rings (907) are connected with the towing rope (904), and the towing rope (904) is towed by mechanical equipment or manually. The fishing net (902) includes four main load-bearing belts (902.1). The four main load-bearing belts (902.1) enclose a rectangular structure, and a net pocket is woven on the four main load-bearing belts (902.1). The length of the fishing net (902) is greater than the opening width of the U-shaped guide rod.

12. The operating method of a dual-channel switching system for a sewage treatment plant according to any one of claims 1-11, characterized in that It includes the following steps: Step 1: Use the liquid level sensor, sludge concentration sensor, and flow rate sensor in the intake culvert (1) to monitor and collect the liquid level height H, sludge concentration Cs, and flow rate V in real time. Step 2: Taking the time t as the scanning period, calculate the average liquid level height H in one period avg , the average sludge concentration C s,avg , the average flow velocity V avg ; Step 3: Set the working condition threshold for the rainy season: ① Early warning values It includes: liquid level height early warning value H0, sludge concentration early warning value Cs0, and flow rate early warning value V0. ② The liquid level height is the main index for judging the rainy season, and the sludge concentration and flow rate are secondary indexes. ③For the average liquid level height H avg , the average sludge concentration Cs ,avg , and the average flow velocity V avg perform a weight analysis, and the formula is: wH, wCs, and wV are the weight coefficients of the liquid level height, sludge concentration, and flow rate respectively, and wH + wCs + wV = 1. X is the comprehensive index. Step 4: Set the threshold X0 of the comprehensive index to judge the current working condition: If X > X0, it is judged as the rainy season working condition, and switch to the rainy season treatment system. If X ≤ X0, it is judged as the non-rainy season working condition, and switch to the dry season treatment system. Step 5: If it is judged as the dry season, the control unit sends an instruction to the switching valve (24) to adjust it to the position pointing to the dry season treatment system. If it is judged as the rainy season, the control unit sends an instruction to the switching valve (24) to adjust it to the position pointing to the rainy season treatment system.

13. The operating method of a dual-channel switching system for a sewage treatment plant according to claim 12, characterized in that: When there are too many floating objects at the entrance of the self-cleaning grille (13), start the floating object emergency fishing device (9) to fish the floating objects in batches. The fishing process is as follows: All the sliding buckles (903) are uniformly sleeved on the curved guide rod (901) from one end of the curved guide rod (901). Then one end of the fishing net (902) is towed and slid through the towing rope (904), and the other end of the fishing net (902) is pulled cooperatively through the towing rope (904). When the sliding buckle (903) at one end of the fishing net (902) is towed to the other end of the curved guide rod (901), the fishing net (902) is fully unfolded. Simultaneously lift the traction ropes (904) at both ends of the fishing net (902) to fish out the floating objects on the surface of the sewage; After one fishing operation is completed, deploy the fishing net (902) below the floating objects in the same way. The deployment process of the fishing net (902) will not be interfered by the floating objects.

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