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

Abstract

A dual-channel switching system and operation method for a sewage treatment plant, including an inlet culvert, the inlet culvert is connected to a dry season treatment system and a rainy season treatment system respectively; the dry season treatment system includes a coarse and fine combination grid, the coarse and fine combination grid is connected to a sand settling tank, a membrane grid device, an AAO combination tank, a MER reaction tank and a first ultraviolet disinfection channel in sequence according to a process sequence; the rainy season treatment system includes a self-cleaning grid, the self-cleaning grid is connected to a flow regulating valve, a combined flow storage tank, a magnetic precipitation system, a fiber rotary filter tank and a second ultraviolet disinfection channel in sequence according to a process sequence; the inlet culvert is provided with a liquid level sensor, a sludge concentration sensor and a flow rate sensor, the process front end of the self-cleaning grid is provided with a switching valve, and the liquid level sensor, the sludge concentration sensor and the flow rate sensor are electrically connected to a control unit. The present invention can automatically adjust the sewage treatment path according to the season and water volume changes, and effectively respond to the sewage treatment needs in the dry season and the rainy season.

Description

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 operation method for a sewage treatment plant. Background Art

[0002] In the field of sewage treatment, it is crucial to design and implement effective treatment strategies based on the characteristics of sewage under different seasons and climatic conditions. Especially in the rainy season, a large amount of rainwater flows into the sewage treatment system, bringing challenges of high flow and high suspended solids concentration, which puts higher requirements on the normal operation of sewage treatment plants. Traditional sewage treatment systems often lack the ability to automatically adjust the treatment path according to seasonal changes. In the rainy season, due to the large influx of rainwater, the concentration of suspended solids and impurities in sewage increases sharply. A single treatment process is difficult to cope with this high load condition, which may lead to a decrease in treatment efficiency or even exceed the treatment capacity, causing environmental pollution. In the dry season, the amount of sewage is relatively small, but the concentration of pollutants is high, requiring more sophisticated treatment methods. Therefore, the existing system has limitations in flexibility and adaptability. For this reason, there is an urgent need for a dual-channel switching system for sewage treatment plants, which aims to automatically select the most suitable treatment path according to the characteristics of sewage in different seasons to optimize treatment efficiency and cost.

[0003] In addition, during the rainy season, a large amount of rainwater carries floating objects such as leaves, plastic bags, and foam into the treatment system, which may block the water inlet, self-cleaning grilles, and other key equipment, seriously affecting water treatment efficiency and water quality. At present, the main methods for dealing with floating objects include manual cleaning and the use of simple salvage tools such as net bags or long-handled scoop nets. However, these traditional methods have obvious limitations, such as low efficiency, high labor intensity, poor safety, and difficulty in responding and handling quickly when floating objects are dense. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a dual-channel switching system and operation method for a sewage treatment plant, including a dry season treatment system and a rainy season treatment system, which automatically selects the most suitable treatment path by real-time monitoring of the liquid level, sludge concentration and flow rate in the water inlet culvert, combined with intelligent control; it realizes automatic adaptation to the characteristics of sewage in different seasons, greatly improving the operation efficiency and environmental adaptability of the sewage treatment plant. The system not only solves the limitations of traditional sewage treatment processes, but also provides an innovative solution for achieving more economical and environmentally friendly sewage treatment.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A dual-channel switching system for a sewage treatment plant includes an inlet culvert, wherein the inlet culvert is connected to a dry season treatment system and a rainy season treatment system respectively;

[0007] The dry season treatment system comprises a coarse and fine combined grid, which is connected to a grit chamber, a membrane grid device, an AAO combined tank, a MER reaction tank and a first ultraviolet disinfection channel in sequence according to the process sequence;

[0008] The rainy season treatment system includes a self-cleaning grille, which is connected to a flow regulating valve, a combined flow regulating reservoir, a magnetic precipitation system, a fiber rotary filter tank and a second ultraviolet disinfection channel in sequence according to the process sequence;

[0009] The water inlet culvert is provided with a liquid level sensor, a sludge concentration sensor and a flow rate sensor. The process front end of the self-cleaning grille is provided with a switching valve. The liquid level sensor, the sludge concentration sensor and the flow rate sensor are electrically connected to the control unit, and the control unit is used to control the action of the switching valve.

[0010] Preferably, it also includes a sludge treatment system, which includes a sludge pool. The sludge pool is dehydrated by a centrifugal dehydrator, and a sludge transport device is provided at the sludge outlet of the centrifugal dehydrator; the sludge in the MER reaction tank is transported to the sludge pool through the sludge transport device.

[0011] 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.

[0012] Preferably, the sludge from the magnetic sedimentation system and the fiber disc filter is treated by a centrifugal dewatering machine.

[0013] 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.

[0014] 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.

[0015] Preferably, it includes a bent guide rod, a salvage net is provided between the two bent guide rods, a sliding buckle is provided on the salvage net, and the sliding buckle is used to slide along the bent guide rod; both ends of the salvage net are used to install a traction rope; the bent 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.

[0016] Preferably, the sliding buckle comprises 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 four corners of the fishing net, and the semi-annular sliding sleeve is used to slide on the curved guide rod;

[0017] The arc of the semi-annular sliding sleeve exceeds 180 degrees. The two ends of the semi-annular sliding sleeve are respectively provided with inner buckle rods. The ends of the inner buckle rods are provided with balls. The balls are used for rolling cooperation with the curved guide rod.

[0018] Preferably, a suspension rod is provided on the side of the curved guide rod, 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 the support frame;

[0019] 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. Enclosed in a rectangular structure, the four main load-bearing belts. Net bags are woven on them; the length of the salvage net is greater than the opening width of the U-shaped guide rod.

[0020] A method for operating a dual-channel switching system for a sewage treatment plant comprises the following steps:

[0021] 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, flow rate in real time. V ;

[0022] The unit of liquid level height is meter (m);

[0023] The unit of sludge concentration is milligrams per liter (mg / L);

[0024] The unit of flow velocity is meter per second (m / s);

[0025] Step 2: Take time t as the scanning period and calculate the average liquid level height in one period H avg , average sludge concentration C s,avg , average flow rate V avg ;

[0026] Step 3: Set the rainy season threshold:

[0027] ① Warning values ​​include: Liquid level height warning value H 0. Sludge concentration warning value Cs 0. Flow rate warning value V 0;

[0028] ②Liquid level height is the main indicator for judging the rainy season, while sludge concentration and flow rate are secondary indicators;

[0029] ③ Average liquid level height H avg , average sludge concentration Cs ,avg , average flow rate V avg Perform weight analysis, the formula is:

[0030] ;

[0031] wxya , wxya , wxya are the weight coefficients of liquid level, sludge concentration and flow rate, respectively, and wxya + wxya + wxya =1; X is a comprehensive indicator;

[0032] Step 4: Set thresholds for composite indicators X 0, used to judge the current working condition:

[0033] if X > X 0, it is judged as rainy season condition and switched to rainy season processing system;

[0034] if X ≤ X 0, it is judged as non-rainy season condition and switched to dry season processing system;

[0035] 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;

[0036] If it is determined to be the rainy season, the control unit sends a command to the switching valve to adjust it to a position pointing to the rainy season treatment system.

[0037] Preferably, when there are too many floating objects at the entrance 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:

[0038] All the sliding buckles are uniformly sleeved on the bending guide rod from one end of the bending guide rod;

[0039] 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 cooperatively by the traction rope;

[0040] 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;

[0041] 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;

[0042] After one salvage is completed, the salvage net is laid under the floating object in the same way, and the laying process of the salvage net will not be disturbed by the floating object.

[0043] The present invention can achieve the following beneficial effects:

[0044] The dry season treatment system and the rainy season treatment system of the present invention automatically select the most suitable treatment path by real-time monitoring of the liquid level, sludge concentration and flow rate in the water inlet culvert and combining intelligent control. It realizes automatic adaptation to the characteristics of sewage in different seasons and greatly improves the operating efficiency and environmental adaptability of the sewage treatment plant. The system not only solves the limitations of traditional sewage treatment technology, but also provides an innovative solution for achieving more economical and environmentally friendly sewage treatment.

[0045] 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 handling capability and maintenance efficiency, and overall improves the operating efficiency and flexibility of the sewage treatment plant.

[0046] The floating object 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 clean floating objects on the water surface without interrupting the water treatment process, significantly improving the operating efficiency and safety of the sewage treatment plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0048] Figure 1 It is a process flow chart of the present invention;

[0049] Figure 2 It is a three-dimensional structural diagram of the floating object emergency salvage device;

[0050] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0051] Figure 4 This is a side view of the floating object emergency salvage device (in use state one);

[0052] Figure 5 This is a side view of the floating object emergency salvage device (in use status 2);

[0053] Figure 6 This is a structural diagram of the connection between the salvage net and the sliding buckle of the floating object emergency salvage device;

[0054] Figure 7 This is a top view of the emergency salvage device for floating objects;

[0055] Figure 8 This is the installation location diagram of the floating object emergency salvage device.

[0056] In the figure: water inlet culvert 1, coarse and fine combination grille 2, sand settling tank 3, membrane grille device 4, AAO combination tank 5, MER reaction tank 6, first ultraviolet 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 903.4, traction rope 904, suspension rod 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 grid 13, flow regulating valve 14, combined flow regulating tank 15, magnetic sedimentation 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

[0057] The preferred solution is Figures 1 to 8 As shown, a dual-channel switching system for a sewage treatment plant includes an inlet culvert 1, and the inlet culvert 1 is connected to a dry season treatment system and a rainy season treatment system respectively;

[0058] The dry season treatment system includes a coarse and fine combined grid 2, which is 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 in sequence according to the process sequence; the waste residue of the coarse and fine combined grid 2 is discharged by a waste residue discharge device 20, which is a auger conveyor or the like.

[0059] The rainy season treatment system includes a self-cleaning grille 13, which is connected to a flow regulating valve 14, a combined flow storage tank 15, a magnetic precipitation system 16, a fiber rotary filter tank 17 and a second ultraviolet disinfection channel 18 in sequence according to the process sequence;

[0060] The water inlet culvert 1 is provided with a liquid level sensor, a sludge concentration sensor and a flow rate sensor. The process 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 electrically connected to the control unit, and the control unit is used to control the action of the switching valve 24.

[0061] The water inlet culvert 1 is used as the water inlet point to connect the dry season treatment system and the rainy season treatment system. The dry season treatment system includes a coarse and fine combination screen 2, a sand settling tank 3, a membrane screen device 4, an AAO combination tank 5, a MER reaction tank 6 and a first ultraviolet disinfection channel 7. The rainy season treatment system includes a self-cleaning screen 13, a flow regulating valve 14, a combined flow storage tank 15, a magnetic precipitation system 16, a fiber rotary filter 17 and a second ultraviolet disinfection channel 18. The dry season treatment system and the rainy season treatment system are switched by a switching valve 24. The switching valve 24 is located at the process front end of the self-cleaning screen 13. It is used to automatically control the opening or closing of the control unit according to the liquid level, sludge concentration and flow rate sensor signals in the water inlet culvert 1, so as to realize the switching of the dry season and rainy season treatment paths. The control unit can select Siemens SIMATIC S7 series PLC, which is suitable for small to large automation tasks.

[0062] 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 discharge port of the centrifugal dehydrator 11; the sludge in the MER reaction tank 6 is transported to the sludge tank 12 through a sludge transport device.

[0063] The sludge treatment system includes a sludge tank 12, which is dehydrated by a centrifugal dehydrator 11, and a sludge transport device 10 is provided at the sludge outlet. The sludge from the MER reaction tank 6 is transported to the sludge tank 12 by a sludge transport device. The sludge produced by the magnetic precipitation system 16 and the fiber rotary filter tank 17 is also treated by the centrifugal dehydrator 11.

[0064] 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.

[0065] 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.

[0066] Furthermore, the sludge from the magnetic sedimentation system 16 and the fiber disc filter 17 is processed by a centrifugal dewatering machine 11 .

[0067] 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 .

[0068] 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 .

[0069] Furthermore, 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.

[0070] A transition channel 25 is provided between the self-cleaning grille 13 and the switching valve 24, and a floating object emergency salvage device 9 is built in, including a bent guide rod 901, a salvage net 902, a sliding buckle 903, a traction rope 904 and other components, which are used to deal with the situation where there are too many floating objects.

[0071] It 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 ; and traction ropes 904 are installed at both ends of the salvage net 902 .

[0072] The curved guide rod 901 can be selected from an arc rod, a semicircular rod, etc. The lower half of the curved guide rod 901 is used to sink into the water, and the sliding buckle 903 is used to be sleeved on the curved guide rod 901. When in use, all the sliding buckles 903 are uniformly sleeved on the curved guide rod 901 from one end of the curved guide rod 901, and 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. 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 completely unfolded. When there are too many floating objects on the surface of the sewage, the traction ropes 904 at both ends of the salvage net 902 are lifted at the same time to salvage the floating objects on the surface of the sewage. After salvaging once, the salvage net 902 is laid below the floating objects in the same way, and the laying process of the salvage net 902 will not be disturbed by the floating objects.

[0073] 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.

[0074] The salvage net 902 is located between the two U-shaped guide rods. The length of the salvage net 902 is greater than the opening width of the U-shaped guide rods, and the width of the salvage net 902 is slightly greater than the distance between the two U-shaped guide rods. Figure 1 The salvage net 902 is shown to be in a taut state, but in actual use, the salvage net 902 is preferably provided with a concave structure net bag, so as to facilitate the salvage of more floating objects at one time.

[0075] 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, which are respectively installed at 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.

[0076] The semi-annular sleeve 903.2 and the rotating seat 903.1 are in rotational cooperation, and the semi-annular sleeve 903.2 is used to be sleeved on the curved guide rod 901; the semi-annular sleeve 903.2 can rotate adaptively with the change of the orientation of the salvage net 902. The rotating seat 903.1 and the salvage net 902 can be connected by a buckle or a tether.

[0077] Furthermore, the arc of the semi-annular sleeve 903.2 exceeds one hundred and eighty degrees, and the two ends of the semi-annular sleeve 903.2 are respectively provided with inner buckle rods 903.3, and the ends of the inner buckle rods 903.3 are provided with balls 903.4, and the balls 903.4 are used for rolling cooperation with the curved guide rod 901.

[0078] The ball bearing 903.4 is 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.

[0079] Furthermore, a suspension rod 905 is provided on the side of the curved guide rod 901, the diameter of the suspension rod 905 is smaller than the diameter of the curved guide rod 901, and the diameter of the suspension rod 905 is smaller than the distance between the two balls 903.4; the semi-annular sleeve 903.2 is used to slide along the curved guide rod 901, and the opening of the semi-annular sleeve 903.2 can pass through the suspension rod 905; the suspension rod 905 is used to connect the support frame.

[0080] The support frame suspends two curved guide rods 901 in the water through the suspension rod 905. The curved guide rod 901 is not completely sunk to the bottom of the water, which can facilitate the sliding buckle 903 to run smoothly from one end of the curved guide rod 901 to the other end. The suspension rod 905 will affect the operation of the sliding buckle 903. In order to avoid the conflict between the sliding buckle 903 and the suspension rod 905, the floating object emergency salvage device refines the structure of the sliding buckle 903. The specific structure is: the semi-annular sliding sleeve 903.2 is not completely closed, and the two balls 903.4 are kept at a sufficient distance to pass through the suspension rod 905. The diameter of the suspension rod 905 is smaller than the diameter of the curved guide rod 901, and the suspension rod 905 is L-shaped, so that the sliding buckle 903 can pass through the suspension rod 905 and will not detach 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.

[0081] Furthermore, a counterweight pendant 906 is provided at one end of the salvage net 902 .

[0082] When the salvage net 902 is installed on the curved guide rod 901, the counterweight pendant 906 can provide a downward pulling force, so that one end of the salvage net 902 can be smoothly pulled downward.

[0083] 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.

[0084] This device is an emergency device and is used less frequently. If there are too many floating objects and the self-cleaning grille cannot handle a large amount of floating objects in a short time, this device can be put into use. The traction method can be manual traction. If the manpower is insufficient to clean the floating objects, the traction rope 904 can be pulled by a winch.

[0085] Furthermore, the salvage net 902 includes four main load-bearing belts 902.1, which enclose a rectangular structure, and 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.

[0086] The four main load-bearing belts 902.1 may be made of nylon belts to ensure sufficient mechanical strength while also having a certain degree of softness.

[0087] The location where this device is used is selected at the front end of the self-cleaning grille process. In some sewage treatment plants, two treatment processes are used: dry season and rainy season. The rainy season refers to the period of time when there is sufficient rain. When the water level rises in the rainy season, more floating objects will be generated. The entrance of the rainy season treatment process will pass through the self-cleaning grille. When the self-cleaning grille cannot quickly clean up a large number of floating objects, this device can be put into use for emergency treatment.

[0088] The functions of other devices in this system are as follows:

[0089] The self-cleaning grille is a pre-treatment device used at the front end of the water treatment system. Its main function is to intercept and remove larger suspended solids, floating objects and solid particles in the water to protect subsequent water treatment equipment from damage. The design of the self-cleaning grille enables it to automatically remove dirt accumulated on the grille 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 grille: Including grille frame: used to support and fix the grille plate, usually made of corrosion-resistant materials such as stainless steel or fiberglass. Grille plate: composed of a series of parallel bars, and the gap between the bars is designed according to the size of the solid particles to be intercepted. Cleaning device: including drive mechanism, cleaning brush or rake teeth, control device, etc., used to remove dirt on the grille plate.

[0090] AAO (Anaerobic-Anoxic-Oxic) combined pool, also known as A2O (Anaerobic-Anoxic-Oxic) pool, is a biological treatment process widely used in the field of sewage treatment, mainly for nitrogen and phosphorus removal. This process combines anaerobic, anoxic and aerobic environments to achieve efficient removal of organic matter, nitrogen and phosphorus in sewage. Detailed working principle and components of AAO combined pool: 1. Anaerobic section (Anaerobic): release of phosphorus and ammoniation of some organic matter. Under anaerobic conditions, polyphosphate bacteria will release phosphate stored in the body and decompose some organic matter, providing conditions for the subsequent aerobic section to absorb phosphorus. 2. Anoxic section (Anoxic): denitrification, reducing nitrate to nitrogen gas. In anoxic environment, denitrifying bacteria use organic matter as electron donors to reduce nitrate to nitrogen gas, thereby achieving nitrogen removal. 3. Aerobic section (Oxic): oxidation of organic matter, nitrification and absorption of phosphorus. In an aerobic environment, aerobic microorganisms oxidize organic matter into carbon dioxide and water, while nitrifying bacteria convert ammonia nitrogen into nitrite and nitrate. Polyphosphate bacteria reabsorb phosphorus during this stage and store it in their cells.

[0091] MBR (Membrane Bioreactor) reaction tank, namely membrane bioreactor, is a high-efficiency sewage treatment system that combines biological treatment technology and membrane separation technology. The core of the MBR system is to use membrane components for solid-liquid separation, replacing the traditional secondary sedimentation tank, so that the concentration of activated sludge in the biological treatment unit can be maintained at a high level, thereby improving the biochemical treatment efficiency and effluent water quality. The activated sludge (microorganisms) in the MBR reaction tank decomposes organic matter and some inorganic matter in the water under aerobic or anaerobic conditions, undergoes biodegradation and transformation, and produces carbon dioxide, water and new substances. The growth and metabolic activities of microorganisms continue in the MBR, forming high-concentration biofilms and suspended activated sludge. Submerged or external membrane components are used in the MBR reaction tank. These membrane components can be flat membranes, tubular membranes, hollow fiber membranes, etc. The membrane components intercept activated sludge and suspended solids through filtering, allowing only clean water to pass through, thereby achieving solid-liquid separation. After the clean water (permeate) is filtered through the membrane, the water quality is clear and the suspended solid content is extremely low, and it can be directly discharged or reused.

[0092] The fiber disc filter is a highly efficient water treatment equipment, which is often used in the deep treatment stage of sewage treatment plants to remove suspended solids, microorganisms and some dissolved organic matter in water to meet the discharge standards or reuse water quality requirements. Its main functions include filtration, biodegradation and disinfection, etc. It is particularly suitable for removing suspended solids, turbidity, chromaticity and some pathogens in sewage. The core component of the fiber disc filter is the fiber disc, which is usually composed of a large number of slender fiber bundles. The fiber bundles are fixed on the disc, and the disc is installed in the filter tank through the central axis and can rotate slowly. When the sewage to be treated enters the filter tank, the water flow will pass through the gaps between the fiber bundles. The surface area of ​​the fiber bundles is very large, which can capture suspended solids and colloidal substances in the water to achieve filtering. Due to the special structure of the fiber bundles, turbulence will form when the water flows through, which helps to improve the filtration effect and prevent the fiber bundles from clogging.

[0093] The magnetic precipitation system is a highly efficient water treatment technology used to remove suspended solids, colloidal substances, certain soluble substances and microorganisms from water. It enhances the precipitation effect by adding magnetic particles (usually magnetic powder) during the conventional coagulation and flocculation process, thereby achieving faster and more thorough water purification. The basic working principle of the magnetic precipitation system is to add magnetic particles during the coagulation and flocculation process, which combine with suspended matter and flocs in the water to form so-called "magnetic flocs". Since the specific gravity of magnetic particles is much higher than that of water, the sedimentation rate of magnetic flocs is significantly accelerated. The working principle of the system is as follows: First, coagulants (such as polyaluminium chloride PAC) and coagulants (such as polyacrylamide PAM) are added to the water to be treated to promote the coagulation of suspended matter and colloidal substances into larger flocs. During the flocculation process, magnetic particles (magnetic powder) are added, and the magnetic powder combines with flocs to form magnetic flocs. Due to the increased specific gravity of magnetic flocs, they can settle in the sedimentation tank at a much higher rate than ordinary flocs, usually within a few hours, while conventional sedimentation may take several days. After precipitation, the magnetic flocs are recovered by magnetic separation technology (such as magnetic drum), and the magnetic powder can be recycled, reducing the consumption of reagents. The supernatant (water from which most of the suspended matter has been removed) is collected and sent to the next treatment stage, such as disinfection, deep treatment, etc.

[0094] Combined sewerage reservoirs are mainly used to treat and control the mixed flow of rainwater and sewage in combined sewer systems. In a combined sewer system, rainwater runoff and domestic sewage or industrial wastewater share a set of pipe systems. This system works well on sunny days, but when the rainfall is heavy, the mixed flow of rainwater and sewage may exceed the treatment capacity of the sewage treatment plant, resulting in the direct discharge of untreated sewage into the water body, causing environmental pollution. To solve this problem, combined sewerage reservoirs are designed to store this part of the excess mixed flow until the weather improves, and then gradually treat and discharge it. The working principle is: when the rain starts, rainwater runoff and sewage are collected into the reservoir through the combined sewer pipe system. At the beginning of the rainfall, the rainwater in the mixed flow contains a higher concentration of pollutants (initial rainwater), and this part of water is collected first. When the amount of mixed flow exceeds the treatment capacity of the sewage treatment plant, the reservoir begins to store excess water. The capacity design of the reservoir is usually sufficient to cope with a certain intensity of rainfall events to prevent the mixed flow from being discharged directly without treatment. After the rainfall ends, the mixed flow in the storage tank is gradually transported 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.

[0095] An operating method for a dual-channel switching system for a sewage treatment plant, characterized in that:

[0096] 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, flow rate in real time. V ;

[0097] The unit of liquid level height is meter (m);

[0098] The unit of sludge concentration is milligrams per liter (mg / L);

[0099] The unit of flow velocity is meter per second (m / s);

[0100] Step 2: Take time t as the scanning period and calculate the average liquid level height in one period H avg , average sludge concentration C s,avg , average flow rate V avg ;

[0101] Step 3: Set the rainy season threshold:

[0102] ① Warning values ​​include: Liquid level height warning value H 0. Sludge concentration warning value Cs 0. Flow rate warning value V 0;

[0103] ②Liquid level height is the main indicator for judging the rainy season, while sludge concentration and flow rate are secondary indicators;

[0104] ③ Average liquid level height H avg , average sludge concentration Cs ,avg , average flow rate V avg Perform weight analysis, the formula is:

[0105] ;

[0106] wxya , wxya , wxya are the weight coefficients of liquid level, sludge concentration and flow rate, respectively, and wxya + wxya + wxya =1; X is a comprehensive indicator;

[0107] Step 4: Set thresholds for composite indicators X 0, used to judge the current working condition:

[0108] if X > X 0, it is judged as rainy season condition and switched to rainy season processing system;

[0109] if X ≤ X 0, it is judged as non-rainy season condition and switched to dry season processing system;

[0110] 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;

[0111] 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.

[0112] When there are too many floating objects at the entrance of the self-cleaning grid 13, the floating object emergency salvage device 9 is started to salvage the floating objects in batches; the salvage process is as follows:

[0113] All the sliding buckles 903 are uniformly sleeved on the curved guide rod 901 from one end of the curved guide rod 901;

[0114] 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;

[0115] 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;

[0116] At the same time, lift the traction ropes 904 at both ends of the salvage net 902 to salvage the floating objects on the surface of the sewage;

[0117] After salvaging is completed once, the salvage net 902 is deployed under the floating object in the same manner, and the deployment process of the salvage net 902 will not be disturbed by the floating object.

[0118] The above embodiments are only preferred technical solutions of the present invention and should not be regarded as limiting the present invention. The protection scope of the present invention shall be the technical solutions recorded in the claims, including equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope 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), 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) in a process sequence; The rainy season treatment system comprises a self-cleaning grille (13), which is connected in sequence to a flow regulating valve (14), a combined flow regulating reservoir (15), a magnetic precipitation system (16), a fiber rotary filter (17) and a second ultraviolet disinfection channel (18) according to a process sequence; The water inlet culvert (1) is provided with a liquid level sensor, a sludge concentration sensor and a flow rate sensor, the process front end of the self-cleaning grid (13) is provided with a switching valve (24), the liquid level sensor, the sludge concentration sensor and the flow rate sensor are electrically connected to a control unit, and the control unit is used to control the action of the switching valve (24); 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; 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.

2. A dual-channel switching system for a sewage treatment plant according to claim 1, characterized in that: 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 sedimentation 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 aeration device (22) and a carbon supply device (23).

6. A dual-channel switching system for a sewage treatment plant according to claim 1, characterized in that: The sliding buckle (903) comprises a rotating seat (903.1), and the rotating seat (903.1) is rotatably connected to the 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). The semi-annular sliding sleeve (903.2) is used to slide on the curved guide rod (901).

7. A dual-channel switching system for a sewage treatment plant according to claim 6, characterized in that: The arc of the semi-annular sliding sleeve (903.2) exceeds 180 degrees. The two ends of the semi-annular sliding sleeve (903.2) are respectively provided with inner buckling rods (903.3). The ends of the inner buckling rods (903.3) are provided with balls (903.4). The balls (903.4) are used for rolling cooperation with the curved guide rod (901).

8. A dual-channel switching system for a sewage treatment plant according to claim 7, characterized in that: A suspension rod (905) is provided on the side of the curved guide rod (901); the diameter of the suspension rod (905) is smaller than the diameter of the curved guide rod (901), and the diameter of the suspension rod (905) is smaller than the distance between the two balls (903.4); the semi-annular sliding sleeve (903.2) is used for sliding along the curved guide rod (901), and the opening of the semi-annular sliding sleeve (903.2) can pass through the suspension rod (905); and the suspension rod (905) is used for connecting the support frame.

9. A dual-channel switching system for a sewage treatment plant according to claim 8, characterized in that: A counterweight pendant (906) is provided at one end of the salvage net (902); the salvage net (902) is provided with at least four pull rings (907), the pull rings (907) are connected to a traction rope (904), and the traction rope (904) is pulled by mechanical equipment or manually; the salvage net (902) comprises four main load-bearing belts (902.1), the four main load-bearing belts (902.1) are surrounded by a rectangular structure, and 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.

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