A precise phosphorus removal and dosing system for sewage treatment plants

Abstract

The invention discloses a precise phosphorus removal and dosing system for a sewage treatment plant. The system comprises a sewage treatment facility, a reagent dosing facility, a water quality and water quantity monitoring instrument and a control device. The sewage treatment facility comprises an inlet pump room, an anaerobic tank, an anoxic tank, an aerobic tank, a secondary sedimentation tank, an intermediate lifting pump room, a reaction tank, a sedimentation tank, a filter tank and an outlet channel which are connected in sequence. The reagent dosing facility comprises an anaerobic tank carbon source dosing facility, an aerobic tank phosphorus removal agent dosing facility and a reaction tank phosphorus removal agent dosing facility. The water quality and water quantity monitoring instrument comprises an inlet total phosphorus online monitoring instrument, an inlet electromagnetic flowmeter, a secondary sedimentation tank outlet orthophosphate online monitoring instrument, a deep inlet electromagnetic flowmeter and an outlet total phosphorus online monitoring instrument. The system's lifting pump, reagent dosing facility and water quality and water quantity monitoring instrument are all connected to the control device. The system organically combines biological phosphorus removal, synchronous chemical phosphorus removal and post-chemical phosphorus removal to achieve precise dosing of phosphorus removal agents, improve the phosphorus removal effect of sewage, reduce phosphorus removal costs, and at the same time improve the automation level of the sewage plant and reduce manual operation intensity.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, and in particular to a precise phosphorus removal and dosing system for a sewage treatment plant. Background Art

[0002] Phosphorus is one of the key factors causing eutrophication of water bodies. In recent years, as the problem of eutrophication of water bodies has become increasingly prominent, reducing phosphorus emissions in urban sewage treatment has become a key link in controlling eutrophication of water bodies, and efficient phosphorus removal in urban sewage treatment plants has become an important research topic in the field of sewage treatment.

[0003] There are two methods for phosphorus removal in sewage treatment plants: biological phosphorus removal and chemical phosphorus removal. Biological phosphorus removal is widely used as an economical and effective phosphorus removal technology, but biological phosphorus removal alone cannot meet the increasingly stringent emission standards. Most sewage treatment plants adopt phosphorus removal measures that are mainly chemical phosphorus removal or mainly biological phosphorus removal and supplemented by chemical phosphorus removal, and achieve the purpose of deep phosphorus removal by supplementing chemical phosphorus removal.

[0004] At present, sewage treatment plants generally adopt an operation mode of manually adjusting the dosage of chemicals according to the effluent quality. However, due to the increased fluctuations in the quality and quantity of the sewage treatment plant's influent and the long residence time, there are problems such as untimely adjustment, large dosage of chemicals, unstable water quality, high manual operation intensity and high operating costs in manually adjusting the dosage of chemicals. Although some sewage treatment plants have begun to try and apply automatic dosing systems for chemical phosphorus removal, they mostly use a single factor control method, which makes it difficult to achieve precise dosing control of phosphorus removal chemicals. Therefore, it is necessary to establish a comprehensive sewage treatment plant precise phosphorus removal and dosing system to solve the above problems. Summary of the invention

[0005] The present invention aims to provide a precise phosphorus removal and dosing system for a sewage treatment plant, which can achieve precise dosing of phosphorus removal agents, improve the phosphorus removal effect of sewage, reduce the phosphorus removal cost, and at the same time improve the automation level of the sewage plant and reduce the intensity of manual operation.

[0006] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present invention is as follows: it comprises an inlet pump room, an anaerobic tank, an anoxic tank, an aerobic tank, a secondary sedimentation tank, an intermediate lift pump room, a reaction tank, a sedimentation tank, a filter tank and an outlet channel connected in sequence; the aerobic tank is connected to a dephosphorization agent dosing device through a biochemical tank dephosphorization agent dosing diaphragm pump; the reaction tank is connected to the dephosphorization agent dosing device through a deep dephosphorization agent dosing diaphragm pump; the anaerobic tank is connected to a carbon source dosing device through a carbon source dosing diaphragm pump; the inlet pump room is connected to the anaerobic tank through an inlet lift pump; the bottom of the secondary sedimentation tank is connected to the anaerobic tank through an external reflux pump; the intermediate lift pump room is connected to the reaction tank through an intermediate lift pump.

[0007] The water inlet pump room is provided with inlet water quality and water quantity monitoring instruments, the intermediate lifting pump room is provided with secondary sedimentation tank effluent water quality monitoring instruments and deep inlet water quantity monitoring instruments, and the outlet channel is provided with effluent water quality monitoring instruments.

[0008] It also includes a control device, which is respectively connected to the inlet water quality and water quantity monitoring instrument, the secondary sedimentation tank effluent water quality monitoring instrument and the deep inlet water quantity monitoring instrument, and the effluent water quality monitoring instrument, and reads the data of the above-mentioned monitoring instruments; the control device is respectively connected to the inlet lift pump, the intermediate lift pump, the carbon source dosing diaphragm pump, the deep phosphorus removal agent dosing diaphragm pump and the biochemical pool phosphorus removal agent dosing diaphragm pump, and reads their flow data, and controls the start and stop of each of the above-mentioned pumps and the flow rate.

[0009] Furthermore, the inlet water quality and water quantity monitoring instruments of the inlet pump room include an inlet water quality monitoring instrument and an inlet water quantity monitoring instrument respectively connected to the inlet pump room.

[0010] Furthermore, the inlet water quality monitoring instrument is an inlet total phosphorus online monitoring instrument, and the inlet water quantity monitoring instrument is an inlet electromagnetic flowmeter.

[0011] Furthermore, the secondary sedimentation tank effluent water quality monitoring instrument is an online monitoring instrument for orthophosphate in the secondary sedimentation tank effluent, and the deep water inlet water volume monitoring instrument is a deep water inlet electromagnetic flowmeter.

[0012] Furthermore, the effluent water quality monitoring instrument of the effluent channel is an effluent total phosphorus online monitoring instrument.

[0013] Furthermore, the dephosphorization agent dosing device includes a dephosphorization agent storage tank, a dephosphorization agent storage tank level gauge, a biochemical pool dephosphorization agent dosing electromagnetic flowmeter and a deep dephosphorization agent dosing electromagnetic flowmeter; the dephosphorization agent storage tank level gauge is located on the dephosphorization agent storage tank and is connected to the control device; further, the inlet ends of the biochemical pool dephosphorization agent dosing diaphragm pump and the deep dephosphorization agent dosing diaphragm pump are respectively connected to the dephosphorization agent storage tank, the outlet end of the biochemical pool dephosphorization agent dosing diaphragm pump is connected to the biochemical pool dephosphorization agent dosing electromagnetic flowmeter, and the outlet end of the deep dephosphorization agent dosing diaphragm pump is connected to the deep dephosphorization agent dosing electromagnetic flowmeter; the outlet end pipeline of the biochemical pool dephosphorization agent dosing electromagnetic flowmeter is laid to the water outlet end of the aerobic pool, and the outlet end pipeline of the deep dephosphorization agent dosing electromagnetic flowmeter is laid to the water inlet end of the reaction tank; the biochemical pool dephosphorization agent dosing electromagnetic flowmeter and the deep dephosphorization agent dosing electromagnetic flowmeter are both connected to the control device.

[0014] Furthermore, the carbon source dosing device includes a carbon source storage tank, a carbon source storage tank level meter, and an anaerobic tank carbon source dosing electromagnetic flowmeter; the carbon source storage tank is provided with a carbon source storage tank level meter, and the carbon source storage tank level meter is connected to the control device.

[0015] Furthermore, the inlet end of the carbon source dosing diaphragm pump is connected to the carbon source storage tank, the outlet end of the carbon source dosing diaphragm pump is connected to the anaerobic tank carbon source dosing electromagnetic flowmeter, and the outlet end pipeline of the anaerobic tank carbon source dosing electromagnetic flowmeter is laid to the anaerobic tank; the anaerobic tank carbon source dosing electromagnetic flowmeter is connected to the control device.

[0016] Furthermore, the control device includes a controller.

[0017] Furthermore, the control device also includes a touch screen, an industrial switch and a host computer. The touch screen and the controller are electrically connected via a communication cable. The host computer and the controller are communicatively connected via an industrial switch networking. The controller is respectively connected to the water inlet lift pump, the intermediate lift pump, the carbon source dosing diaphragm pump, the deep dephosphorus agent dosing diaphragm pump and the biochemical pool dephosphorus agent dosing diaphragm pump via a frequency converter.

[0018] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: the present invention fully collects data from inlet water quality and water quantity monitoring instruments, secondary sedimentation tank effluent water quality monitoring instruments, deep inlet water quantity monitoring instruments and effluent water quality monitoring instruments, realizes continuous determination of inlet and effluent total phosphorus and intermediate process orthophosphate, can timely grasp the inlet total phosphorus load and phosphorus concentration in each link, provides comprehensive data support for phosphorus removal agent addition, and simultaneously sets synchronous precipitation and post-precipitation phosphorus removal agent addition points, constructs a set of chemical phosphorus removal precise dosing control system, can effectively improve the accuracy of phosphorus removal agent addition and the stability of effluent water quality, can effectively reduce the phosphorus removal cost of sewage treatment plants, and effectively improve the automation level of sewage treatment plants.

[0019] The present invention also adds a carbon source dosing device for the anaerobic tank. When the dephosphorization agent dosing system fails, the carbon source dosing pump of the anaerobic tank can be opened in time to improve the biological phosphorus removal efficiency and achieve stable compliance of total phosphorus.

[0020] The biochemical pool dephosphorization agent dosing system provided by the present invention not only plays a role in accurate phosphorus removal, but also has the function of improving sludge settling properties. When the sludge settling properties are poor in winter, adding the dephosphorization agent can improve the sludge settling properties and prevent sludge leakage in the secondary sedimentation tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Attached Figure 1 Schematic diagram of the system structure of Embodiment 2 of the present invention; Figure 2 Attached is a connection diagram of the control device of Example 2 of the present invention; Figure 3 It is a schematic diagram of the pipeline connection of the dephosphorization agent storage tank, the dephosphorization agent dosing electromagnetic flowmeter for the biochemical pool and the deep dephosphorization agent dosing electromagnetic flowmeter in the present invention.

[0022] In the attached drawings: 1 inlet total phosphorus online monitor, 2 secondary sedimentation tank effluent orthophosphate online monitor, 3 effluent total phosphorus online monitor, 4 inlet electromagnetic flowmeter, 5 deep inlet electromagnetic flowmeter, 6 anaerobic tank carbon source dosing electromagnetic flowmeter, 7 biochemical tank dephosphorization agent dosing electromagnetic flowmeter, 8 deep dephosphorization agent dosing electromagnetic flowmeter, 9 carbon source storage tank, 10 dephosphorization agent storage tank, 11 carbon source storage tank level gauge, 12 dephosphorization agent storage tank level gauge, 13 carbon source dosing diaphragm pump, 14 biochemical tank dephosphorization agent dosing diaphragm pump, 15 deep dephosphorization agent dosing diaphragm pump, 16 inlet lift pump, 17 external reflux pump, 18 intermediate lift pump, 19 inlet pump room, 20 anaerobic tank, 21 anoxic tank, 22 aerobic tank, 23 secondary sedimentation tank, 24 intermediate lift pump room, 25 reaction tank, 26 sedimentation tank, 27 filter tank, 28 outlet channel, 29 control device. DETAILED DESCRIPTION

[0023] The present invention is described in further detail below with reference to the accompanying drawings.

[0024] Embodiment 1 A precise phosphorus removal and dosing system for a sewage treatment plant, the system comprising sewage treatment facilities, chemical dosing facilities, water quality and quantity monitoring instruments and control devices; the sewage treatment facilities comprise an inlet pump room 19, an anaerobic tank 20, an anoxic tank 21, an aerobic tank 22, a secondary sedimentation tank 23, an intermediate lift pump room 24, a reaction tank 25, a sedimentation tank 26, a filter tank 27 and an outlet channel 28 connected in sequence; the chemical dosing facilities comprise an aerobic tank dephosphorization agent dosing facility and a reaction tank dephosphorization agent dosing facility; the inlet pump room 19 is provided with an inlet total phosphorus online monitor 1 and an inlet electromagnetic flowmeter 4, and the intermediate lift pump room 24 is provided with The effluent from the secondary sedimentation tank is equipped with an online orthophosphate monitor 2 and a deep inlet electromagnetic flowmeter 5, and the effluent total phosphorus online monitor 3 is provided in the effluent channel 28; the system's reagent addition facilities and water quality and quantity monitoring instruments are all connected to the control device 29; the system organically combines biological phosphorus removal, synchronous chemical phosphorus removal and post-chemical phosphorus removal, and can adjust the dosage of phosphorus removal agents in a timely and efficient manner according to changes in the influent water quality and quantity of the sewage treatment plant and the process operation conditions, thereby achieving accurate addition of phosphorus removal agents, making the effluent total phosphorus stably meet the standards, and reducing the phosphorus removal cost. At the same time, the system has a high degree of automation, which can effectively reduce the operating intensity of employees.

[0025] Specifically, the present invention includes an inlet pump room 19, an anaerobic tank 20, an anoxic tank 21, an aerobic tank 22, a secondary sedimentation tank 23, an intermediate lift pump room 24, a reaction tank 25, a sedimentation tank 26, a filter tank 27 and an outlet channel 28, which are connected in sequence; the aerobic tank 22 is connected to a dephosphorization agent dosing device through a biochemical tank dephosphorization agent dosing diaphragm pump 14; the reaction tank 25 is connected to the dephosphorization agent dosing device through a deep dephosphorization agent dosing diaphragm pump 15; the inlet pump room 19 is connected to the anaerobic tank 20 through an inlet lift pump 16; the secondary sedimentation tank 23 is connected to the anaerobic tank 20 through an external reflux pump 17; the intermediate lift pump room 24 is connected to the reaction tank 25 through an intermediate lift pump 18.

[0026] The water inlet pump room 19 is provided with inlet water quality and water quantity monitoring instruments, the intermediate lifting pump room 24 is provided with secondary sedimentation tank effluent water quality monitoring instruments and deep inlet water quantity monitoring instruments, and the outlet channel 28 is provided with effluent water quality monitoring instruments.

[0027] It also includes a control device 29, which is respectively connected to the inlet water quality and water quantity monitoring instrument, the secondary sedimentation tank effluent water quality monitoring instrument, the deep inlet water quantity monitoring instrument and the effluent water quality monitoring instrument and reads the data of the above-mentioned monitoring instruments; the control device 29 is respectively connected to the inlet lift pump 16, the intermediate lift pump 18, the carbon source dosing diaphragm pump 13, the biochemical pool dephosphorization agent dosing diaphragm pump 14 and the deep dephosphorization agent dosing diaphragm pump 15 and reads their flow data, and can control the start and stop of each of the above-mentioned pumps and the flow rate.

[0028] The water quality and water quantity monitoring instruments of the water inlet pump room include a water quality monitoring instrument and a water quantity monitoring instrument connected to the water inlet pump room respectively. The water quality monitoring instrument is an online monitoring instrument for total phosphorus in water 1, and the water quantity monitoring instrument is an electromagnetic flowmeter 4.

[0029] The water quality monitoring instrument for the secondary sedimentation tank effluent of the lift pump room is an online monitoring instrument 2 for orthophosphate in the secondary sedimentation tank effluent, and the deep water inlet water quantity monitoring instrument is a deep water inlet electromagnetic flowmeter 5.

[0030] The effluent water quality monitoring instrument of the effluent channel is an effluent total phosphorus online monitoring instrument 3.

[0031] The dephosphorization agent dosing device comprises a dephosphorization agent storage tank 10, a dephosphorization agent storage tank level meter 12, a biochemical pool dephosphorization agent dosing electromagnetic flowmeter 7 and a deep dephosphorization agent dosing electromagnetic flowmeter 8; the inlet ends of the biochemical pool dephosphorization agent dosing diaphragm pump 14 and the deep dephosphorization agent dosing diaphragm pump 15 are respectively connected to the dephosphorization agent storage tank 10, and the outlet ends of the biochemical pool dephosphorization agent dosing diaphragm pump 14 and the deep dephosphorization agent dosing diaphragm pump 15 are respectively connected to the biochemical pool dephosphorization agent dosing electromagnetic flowmeter 7 and the deep dephosphorization agent dosing electromagnetic flowmeter 8, and the outlet end pipelines of the biochemical pool dephosphorization agent dosing electromagnetic flowmeter 7 and the deep dephosphorization agent dosing electromagnetic flowmeter 8 are respectively laid to the water outlet end of the aerobic pool 22 and the water inlet end of the reaction tank 25; the biochemical pool dephosphorization agent dosing electromagnetic flowmeter 7 and the deep dephosphorization agent dosing electromagnetic flowmeter 8 are both connected to the control device 29.

[0032] The dephosphorization agent tank level meter 12 is placed on the dephosphorization agent tank 10 and connected to the control device 29. The control device 29 can display the agent liquid level in the dephosphorization agent tank 10. The operator can know the remaining amount of the agent in the dephosphorization agent tank 10 in real time so as to arrange the delivery of the agent reasonably.

[0033] The intermediate lifting pump room 24 is connected to the reaction tank 25 through the intermediate lifting pump 18. A deep water inlet electromagnetic flowmeter 5 is arranged on the pipeline between the intermediate lifting pump 18 and the reaction tank 25. The deep water inlet electromagnetic flowmeter 5 is connected to the control device 29. The control device 29 can read the reading of the deep water inlet electromagnetic flowmeter 5 and control the flow size of the intermediate lifting pump 18. The control process of the control device of this embodiment is as follows: the control device 29 automatically calculates the dosage of the biochemical pool synchronous precipitation dephosphorization agent and the dosage of the deep post-precipitation dephosphorization agent according to the readings of the inlet total phosphorus online monitor 1, the inlet electromagnetic flowmeter 4, the secondary sedimentation tank effluent orthophosphate online monitor 2, the deep water inlet electromagnetic flowmeter 5, and the effluent total phosphorus online monitor 3. The dosage of the synchronous precipitation dephosphorization agent in the biochemical pool is the amount of dephosphorization agent transported from the dephosphorization agent storage tank 10 to the aerobic pool through the biochemical pool dephosphorization agent dosing diaphragm pump 14; the dosage of the deep post-precipitation dephosphorization agent is the amount of dephosphorization agent transported from the dephosphorization agent storage tank 10 to the reaction pool 25 through the deep dephosphorization agent dosing diaphragm pump 15.

[0034] The dosage of the synchronous precipitation phosphorus removal agent in the biochemical pool is automatically calculated according to the total phosphorus load of the influent, the biological phosphorus removal rate and the target value of the orthophosphate concentration of the effluent of the secondary sedimentation tank, and the target value of the total phosphorus concentration of the effluent of the secondary sedimentation tank is set to 1 mg / L. When the readings of the online monitor 1 for total phosphorus in the influent, the electromagnetic flowmeter 4 for the influent, and the online monitor 2 for orthophosphate of the effluent of the secondary sedimentation tank change, the control device 29 automatically calculates the dosage of the phosphorus removal agent according to the preset program, and instructs the diaphragm pump 14 for the phosphorus removal agent in the biochemical pool to add according to the calculated flow rate. Specifically, when the synchronous precipitation phosphorus removal load (total phosphorus concentration of influent × influent flow rate - total phosphorus concentration of influent × biological phosphorus removal rate × influent flow rate - set orthophosphate concentration of the effluent of the secondary sedimentation tank × influent flow rate) increases, the control device 29 increases the frequency of the diaphragm pump 14 for the phosphorus removal agent in the biochemical pool and increases the dosage. When the synchronous precipitation phosphorus removal load decreases, the control device 29 reduces the frequency of the diaphragm pump 14 for the phosphorus removal agent in the biochemical pool and reduces the dosage.

[0035] The control system for deep post-precipitation phosphorus removal agent is divided into feedforward control and feedback control, and both feedforward and feedback control belong to the control device 29. The target value of effluent total phosphorus is set to 0.3 mg / L. When the effluent total phosphorus is ≥0.3 mg / L, the feedback program is executed, and when the effluent total phosphorus is ≤0.3 mg / L, the feedforward program is executed. The feedforward control system automatically calculates the dosage of post-precipitation phosphorus removal agent based on the readings of the deep inlet electromagnetic flowmeter 5, the secondary sedimentation tank effluent orthophosphate online monitor 2 and the effluent total phosphorus online monitor 3, and instructs the deep phosphorus removal agent dosing diaphragm pump 15 to add according to the calculated flow rate. The feedback control system performs feedback adjustment based on the deviation between the effluent total phosphorus concentration and the target value. The feedback adjustment adopts PID adjustment. The feedback control system automatically calculates the dosage and instructs the deep phosphorus removal agent dosing diaphragm pump 15 to adjust the dosing flow rate.

[0036] The present invention fully collects data such as influent water volume, deep influent water volume, influent and effluent total phosphorus online monitoring instrument and secondary sedimentation tank effluent orthophosphate online monitoring instrument, realizes continuous determination of influent and effluent total phosphorus and intermediate process orthophosphate, can timely grasp the influent total phosphorus load and phosphorus concentration of each link, provides comprehensive data support for phosphorus removal agent addition, and simultaneously sets synchronous precipitation and post-precipitation phosphorus removal agent addition points, constructs a set of chemical phosphorus removal precise dosing control system, can effectively improve the accuracy of phosphorus removal agent addition and the stability of effluent water quality, and can effectively reduce the phosphorus removal cost and manual operation intensity of sewage treatment plants.

[0037] The present invention combines the online orthophosphate monitoring instrument to control the concentration of the effluent from the secondary sedimentation tank to scientifically and reasonably regulate the dosage of the biochemical pool and the deep dephosphorization agent, thereby improving the synergistic treatment effect of synchronous precipitation and post-precipitation chemical dephosphorization.

[0038] The biochemical pool dephosphorization agent dosing system provided by the present invention not only plays a role in accurate phosphorus removal, but also has the function of improving sludge settling properties. When the sludge settling properties are poor in winter, adding the dephosphorization agent can improve the sludge settling properties and prevent sludge leakage in the secondary sedimentation tank.

[0039] Simultaneous precipitation and phosphorus removal. Since the phosphorus removal agent will accumulate in the biochemical system cycle, when the orthophosphate concentration in the effluent from the secondary sedimentation tank is around 1 mg / L for a long time, you can consider stopping the dosing, and then add the phosphorus removal agent when the orthophosphate concentration shows an upward trend. Intermittent dosing can avoid the accumulation of agents in the sludge and the reduction of biological phosphorus removal efficiency. At the same time, it can reduce the amount of phosphorus removal agent used, thereby achieving efficient synergy between biological phosphorus removal and simultaneous chemical phosphorus removal.

[0040] Example 2 Figure 1-2 As shown, the difference between this embodiment and embodiment 1 is that this embodiment also includes a carbon source dosing device, which includes a carbon source storage tank 9, a carbon source dosing diaphragm pump 13 and an anaerobic tank carbon source dosing electromagnetic flowmeter 6 connected in sequence, the other end of the anaerobic tank carbon source dosing electromagnetic flowmeter is connected to the anaerobic tank 20, the carbon source storage tank 9 is equipped with a carbon source storage tank liquid level meter 11, and the other end of the carbon source storage tank liquid level meter 11 is connected to the control device 29. The specific connection relationship is: the inlet end of the anaerobic tank carbon source dosing diaphragm pump 13 is connected to the carbon source storage tank 9 through a pipeline, and the outlet end of the anaerobic tank carbon source dosing diaphragm pump 13 is connected to the anaerobic tank carbon source dosing electromagnetic flowmeter 6 through a pipeline, and the pipeline at the outlet end of the anaerobic tank carbon source dosing electromagnetic flowmeter 6 is laid to the water inlet end of the anaerobic tank 20, and the anaerobic tank carbon source dosing diaphragm pump 13 and the anaerobic tank carbon source dosing electromagnetic flowmeter 6 are both connected to the control device 29, and the control device 29 can read the flowmeter data and control the start and stop of the diaphragm pump and the flow size.

[0041] The carbon source storage tank level meter 11 is placed on the carbon source storage tank 9 and connected to the control device 29. The control device 29 can display the reagent liquid level in the carbon source storage tank 9. The operator can grasp the remaining amount of reagent in the carbon source storage tank 9 in real time, so as to arrange the delivery of the reagent reasonably.

[0042] The water inlet lift pump 16 is connected to a control device 29 , and the control device 29 can control the start and stop of the water inlet lift pump 16 and the flow rate.

[0043] The connection relationship and control relationship of the control device 29 of the present invention are as follows: Figure 2 As shown, the control device 29 of the present invention includes a controller.

[0044] The control device 29 also includes a touch screen, an industrial switch and a host computer. The touch screen and the controller are connected via a communication bus cable. The host computer and the controller are connected via an industrial switch via optical fiber Ethernet communication. The controller is connected to the water inlet lift pump, the intermediate lift pump, the carbon source dosing diaphragm pump, the deep dephosphorization agent dosing diaphragm pump and the biochemical pool dephosphorization agent dosing diaphragm pump through a frequency converter. Specifically: The controller in this embodiment is a programmable logic controller PLC produced by Siemens, model SIMATIC S7-200 Smart CPUSR60, the controller is provided with bus communication, Ethernet communication port and IO input terminal, IO output terminal, the bus communication port of the controller is electrically connected with the monitor, flow meter and liquid level meter respectively. Specifically, the bus communication port of the controller is electrically connected with the monitors: online monitor 1 for total phosphorus in inlet, online monitor 2 for orthophosphate in effluent from secondary sedimentation tank, online monitor 3 for total phosphorus in effluent, inlet electromagnetic flowmeter 4, deep inlet electromagnetic flowmeter 5, anaerobic tank carbon source dosing electromagnetic flowmeter 6, biochemical tank dephosphorization agent dosing electromagnetic flowmeter 7, deep dephosphorization agent dosing electromagnetic flowmeter 8, carbon source storage tank liquid level meter 11, dephosphorization agent storage tank liquid level meter 12.

[0045] In the implementation of the control system, a touch screen is also provided, which is used to modify operating parameters and display detection data. For example, in actual applications, flow parameters may be adjusted in a targeted manner to achieve a certain technical effect, and input operations can be performed through the touch screen. The touch screen is also used to display detection data from monitors, flow meters, and liquid level meters, so that the staff operating on site can see the current operating status of the water treatment system at a glance. The touch screen and the controller are connected via a bus communication cable. This embodiment is a touch screen produced by Siemens, model 6AV6 648-0CE11-3AX0 (10 inches).

[0046] The host computer is connected to the controller for communication. The host computer and the controller are both arranged in the same local area network, which forms a fiber optic Ethernet through an industrial switch. The controller and the host computer are respectively connected to the industrial switch through optical fibers to achieve stable and high-speed communication between each other. The controller transmits the signal data from the monitor, flow meter and liquid level meter collected by each communication port and the control signal output by the output end to the host computer in the form of messages at high speed and in real time. The host computer displays the detection data obtained by the controller input end and the output end signal in the form of configuration animation, so that the staff next to the host computer can intuitively understand the current operating status of the water treatment system, so that the staff does not have to run around the water treatment system site. The industrial switch in this embodiment is MOXA brand, model EDS-205B-T.

[0047] The controller outputs a control signal to the actuator through the output end, and the control device adjusts the operating parameters of the actuator through its built-in program to control the water treatment process in real time; the actuators in this embodiment are pumps in various links of water treatment, such as the water inlet lift pump, the intermediate lift pump, the carbon source dosing diaphragm pump, the deep dephosphorization agent dosing diaphragm pump and the biochemical pool dephosphorization agent dosing diaphragm pump. The output end of the control device is connected to the frequency converter corresponding to each pump, and a speed control signal is sent to the frequency converter to control the water outlet flow of the pump through different speeds of the pump.

[0048] The water inlet lift pump, the intermediate lift pump, the carbon source dosing diaphragm pump, the deep dephosphorus agent dosing diaphragm pump and the biochemical pool dephosphorus agent dosing diaphragm pump are respectively connected to a frequency converter, and are connected to the controller communication bus through the frequency converter connected to the pump. The frequency converters are all produced by ABB, model ACS580-01-07A2-4 (3KW).

[0049] like Figure 2 As shown, the frequency converters connected to the water inlet lift pump, the intermediate lift pump, the carbon source dosing diaphragm pump, the deep dephosphorus removal agent dosing diaphragm pump and the biochemical pool dephosphorus removal agent dosing diaphragm pump are respectively recorded as the first frequency converter, the second frequency converter, the third frequency converter, the fourth frequency converter and the fifth frequency converter.

[0050] The control process of the control device of the present embodiment 2 is as follows: when the phosphorus removal agent dosing system fails and the phosphorus removal agent cannot be added normally, the control device 29 controls the anaerobic tank carbon source dosing diaphragm pump 13 to add carbon source to the anaerobic tank 20, and controls the water inlet pump room 19 to appropriately reduce the frequency and reduce the water inlet volume when necessary; the carbon source dosage is determined by comparing the reading of the orthophosphate online monitor 2 of the secondary sedimentation tank effluent with the set value of the orthophosphate concentration of the secondary sedimentation tank effluent, and the set value of the orthophosphate concentration of the secondary sedimentation tank effluent is 0.3 mg / L; the reading of the orthophosphate online monitor 2 of the secondary sedimentation tank effluent is fed back to the control device 29, and when the reading of the orthophosphate online monitor of the secondary sedimentation tank effluent is greater than 0.3 mg / L, the control device 29 instructs the anaerobic tank carbon source dosing diaphragm pump 13 to increase the dosage, and when the reading of the orthophosphate online monitor of the secondary sedimentation tank effluent is less than 0.2 mg / L, the control device 29 instructs the anaerobic tank carbon source dosing diaphragm pump 13 to reduce the dosing flow rate.

[0051] The carbon source dosing device added to the anaerobic tank of the present invention can effectively improve the biological phosphorus removal efficiency of the sewage plant, ensure that the total phosphorus in the effluent stably meets the standard, and solve the phosphorus removal problem of sewage when the phosphorus removal agent dosing system of the sewage plant fails.

[0052] The present invention scientifically and cleverly sets the positions of the monitoring instrument and the dosing point, and combines them just right and on the premise of minimizing the cost, so as to effectively improve the biological phosphorus removal efficiency of the sewage treatment plant.

[0053] The connecting pipeline in the present invention is not limited to one, such as Figure 3 As shown, in the present invention, the dephosphorization agent storage tank 10 is divided into four paths through a filter, namely, a first path, a second path, a third path and a fourth path.

[0054] On the one hand, the dephosphorization agent storage tank 10 is connected to the dosing point of the biochemical pool through the biochemical pool dephosphorization agent dosing diaphragm pump 14 and the biochemical pool dephosphorization agent dosing electromagnetic flowmeter 7. Specifically, two passages are arranged between the dephosphorization agent storage tank 10 and the dosing point of the biochemical pool. The dephosphorization agent storage tank 10 is filtered through a filter and then divided into two paths, namely the first path and the second path running in parallel. The first path is connected to a filter, a biochemical pool dephosphorization agent dosing diaphragm pump 14, and a back pressure valve in sequence, and then the second path is combined and connected to the biochemical pool dephosphorization agent dosing electromagnetic flowmeter 7. A safety valve, a pressure gauge and a damper are also arranged between the biochemical pool dephosphorization agent dosing diaphragm pump 14 and the back pressure valve. The second route is the same as the first route. The second route is connected in sequence to a filter, a biochemical pool dephosphorization agent dosing diaphragm pump 14, and a back pressure valve, and then is combined with the first route and connected to the biochemical pool dephosphorization agent dosing electromagnetic flowmeter 7. That is, both routes come out of the back pressure valve and are combined and connected to the biochemical pool dephosphorization agent dosing electromagnetic flowmeter 7.

[0055] On the other hand, the dephosphorization agent storage tank 10 is connected to the dosing point of the reaction tank through the deep dephosphorization agent dosing diaphragm pump 15 and the deep dephosphorization agent dosing electromagnetic flowmeter 8. Specifically, two passages are set between the dephosphorization agent storage tank 10 and the dosing point of the reaction tank. The dephosphorization agent storage tank 10 is filtered by a filter and then divided into two routes, namely the third route and the fourth route running in parallel. The third route is connected to a filter, a deep dephosphorization agent dosing diaphragm pump 15, and a back pressure valve in sequence, and then connected to the deep dephosphorization agent dosing electromagnetic flowmeter 8 after being combined with the fourth route. A safety valve, a pressure gauge and a damper are also provided between the deep dephosphorization agent dosing diaphragm pump 15 and the back pressure valve. The fourth route is the same as the third route. The fourth route is connected to a filter, a deep dephosphorization agent dosing diaphragm pump 15, and a back pressure valve in sequence, and then connected to the deep dephosphorization agent dosing electromagnetic flowmeter 8 after being combined with the third route, that is, both routes are combined and connected to the deep dephosphorization agent dosing electromagnetic flowmeter 8 after coming out of the back pressure valve.

[0056] Using two or more parallel paths can increase processing efficiency and prevent one path from failing and causing downtime.

[0057] The above-described embodiments are only preferred embodiments of the present invention, and are not exhaustive of the feasible implementations of the present invention. For those skilled in the art, any obvious changes made thereto without departing from the principles and spirit of the present invention should be considered to be included in the scope of protection of the claims of the present invention.

Claims

1. A precise phosphorus removal and dosing method for a sewage treatment plant, which relates to a precise phosphorus removal and dosing system for a sewage treatment plant, comprising an inlet pump room, an anaerobic tank, an anoxic tank, an aerobic tank, a secondary sedimentation tank, an intermediate lift pump room, a reaction tank, a sedimentation tank, a filter tank and an outlet channel connected in sequence; characterized in that: The aerobic tank is connected to a dephosphorization agent dosing device via a biochemical tank dephosphorization agent dosing diaphragm pump; the reaction tank is connected to the dephosphorization agent dosing device via a deep dephosphorization agent dosing diaphragm pump; the anaerobic tank is connected to a carbon source dosing device via a carbon source dosing diaphragm pump; the water inlet pump room is connected to the anaerobic tank via a water inlet lift pump; the bottom of the secondary sedimentation tank is connected to the anaerobic tank via an external reflux pump; the intermediate lift pump room is connected to the reaction tank via an intermediate lift pump; The water inlet pump room is provided with water inlet quality and water quantity monitoring instruments, the intermediate lifting pump room is provided with secondary sedimentation tank effluent water quality monitoring instruments and deep water inlet water quantity monitoring instruments, and the outlet channel is provided with effluent water quality monitoring instruments; the deep water inlet water quantity monitoring instrument is a deep water inlet electromagnetic flowmeter; It also includes a control device, which is respectively connected to the inlet water quality and water quantity monitoring instrument, the secondary sedimentation tank effluent water quality monitoring instrument and the deep inlet water quantity monitoring instrument, and the effluent water quality monitoring instrument to read the data of each of the above monitoring instruments; the control device is respectively connected to the inlet lift pump, the intermediate lift pump, the carbon source dosing diaphragm pump, the deep dephosphorization agent dosing diaphragm pump and the biochemical pool dephosphorization agent dosing diaphragm pump to read their flow data, and control the start and stop of each of the above pumps and the flow size; The dephosphorization agent dosing device comprises a dephosphorization agent storage tank, a dephosphorization agent storage tank level meter, a biochemical pool dephosphorization agent dosing electromagnetic flowmeter and a deep dephosphorization agent dosing electromagnetic flowmeter; the dephosphorization agent storage tank level meter is located on the dephosphorization agent storage tank and is connected to the control device; The inlet ends of the dephosphorization agent dosing diaphragm pump for the biochemical pool and the deep dephosphorization agent dosing diaphragm pump are respectively connected to the dephosphorization agent storage tank, the outlet end of the dephosphorization agent dosing diaphragm pump for the biochemical pool is connected to the dephosphorization agent dosing electromagnetic flowmeter for the biochemical pool, and the outlet end of the deep dephosphorization agent dosing diaphragm pump is connected to the deep dephosphorization agent dosing electromagnetic flowmeter; the outlet end pipeline of the dephosphorization agent dosing electromagnetic flowmeter for the biochemical pool is laid to the water outlet end of the aerobic pool, and the outlet end pipeline of the deep dephosphorization agent dosing electromagnetic flowmeter is laid to the water inlet end of the reaction pool; the biochemical pool dephosphorization agent dosing electromagnetic flowmeter and the deep dephosphorization agent dosing electromagnetic flowmeter are both connected to the control device; A deep water inlet electromagnetic flowmeter is provided on the pipeline between the intermediate lift pump and the reaction tank, and the deep water inlet electromagnetic flowmeter is connected to the control device. The control device comprises a controller; The inlet water quality and water quantity monitoring instruments of the inlet pump room include an inlet water quality monitoring instrument and an inlet water quantity monitoring instrument respectively connected to the inlet pump room; The inlet water quality monitoring instrument is an inlet total phosphorus online monitoring instrument, and the inlet water quantity monitoring instrument is an inlet electromagnetic flowmeter; The secondary sedimentation tank effluent water quality monitoring instrument is an online monitoring instrument for orthophosphate in the secondary sedimentation tank effluent, and the effluent water quality monitoring instrument of the effluent channel is an online monitoring instrument for total phosphorus in the effluent; The carbon source dosing device comprises a carbon source storage tank, a carbon source storage tank level meter, and an anaerobic tank carbon source dosing electromagnetic flowmeter; the carbon source storage tank is provided with a carbon source storage tank level meter, and the carbon source storage tank level meter is connected to the control device; The inlet end of the carbon source dosing diaphragm pump is connected to the carbon source storage tank, the outlet end of the carbon source dosing diaphragm pump is connected to the anaerobic tank carbon source dosing electromagnetic flowmeter, and the outlet end pipeline of the anaerobic tank carbon source dosing electromagnetic flowmeter is laid to the anaerobic tank; the anaerobic tank carbon source dosing electromagnetic flowmeter is connected to the control device; The bus communication port of the controller is electrically connected to the monitors: online monitor for total phosphorus in inlet, online monitor for orthophosphate in effluent from the secondary sedimentation tank, online monitor for total phosphorus in effluent, inlet electromagnetic flowmeter, deep inlet electromagnetic flowmeter, anaerobic tank carbon source dosing electromagnetic flowmeter, biochemical tank dephosphorization agent dosing electromagnetic flowmeter, deep dephosphorization agent dosing electromagnetic flowmeter, carbon source storage tank level meter, dephosphorization agent storage tank level meter; The water inlet lift pump, the intermediate lift pump, the carbon source dosing diaphragm pump, the deep dephosphorization agent dosing diaphragm pump and the biochemical pool dephosphorization agent dosing diaphragm pump are respectively connected to a frequency converter. The dephosphorization agent storage tank is divided into four routes through a filter, namely the first route, the second route, the third route and the fourth route; The dephosphorization agent storage tank is connected to the dosing point of the biochemical pool through a dephosphorization agent dosing diaphragm pump for the biochemical pool and an electromagnetic flowmeter for the dephosphorization agent dosing for the biochemical pool. Two passages are arranged between the dephosphorization agent storage tank and the dosing point of the biochemical pool. The dephosphorization agent storage tank is filtered by a filter and then divided into a first passage and a second passage running in parallel. The first passage is sequentially connected to a filter, a dephosphorization agent dosing diaphragm pump for the biochemical pool, and a back pressure valve, and then connected to the dephosphorization agent dosing electromagnetic flowmeter for the biochemical pool after being combined with the second passage. A safety valve, a pressure gauge and a damper are also arranged between the dephosphorization agent dosing diaphragm pump for the biochemical pool and the back pressure valve; the second passage is sequentially connected to a filter, a dephosphorization agent dosing diaphragm pump for the biochemical pool, and a back pressure valve, and then connected to the dephosphorization agent dosing electromagnetic flowmeter for the biochemical pool after being combined with the first passage; The dosage of the synchronous precipitation phosphorus removal agent in the biochemical pool is automatically calculated according to the target values ​​of the total phosphorus load of the influent, the biological phosphorus removal rate and the orthophosphate concentration of the effluent from the secondary sedimentation tank. The target value of the total phosphorus concentration of the effluent from the secondary sedimentation tank is set to 1mg / L; when the readings of the online monitor of the total phosphorus in the influent, the electromagnetic flowmeter of the influent and the online monitor of the orthophosphate of the effluent from the secondary sedimentation tank change, the control device automatically calculates the dosage of the phosphorus removal agent according to the preset program and instructs the diaphragm pump for the phosphorus removal agent dosing in the biochemical pool to add the phosphorus removal agent according to the calculated flow rate; The control of deep post-precipitation phosphorus removal agent is divided into feedforward control and feedback control, both of which belong to control devices; the target value of effluent total phosphorus is set to 0.3 mg / L, and when the effluent total phosphorus is ≥0.3 mg / L, the feedback program is executed, and when the effluent total phosphorus is ≤0.3 mg / L, the feedforward program is executed; the feedforward control system automatically calculates the dosage of post-precipitation phosphorus removal agent according to the readings of the deep water inlet electromagnetic flowmeter, the secondary sedimentation tank effluent orthophosphate online monitor and the effluent total phosphorus online monitor, and instructs the deep phosphorus removal agent dosing diaphragm pump to add according to the calculated flow rate; the feedback control system performs feedback adjustment according to the deviation between the effluent total phosphorus concentration and the target value, and the feedback adjustment adopts PID adjustment. The feedback control system automatically calculates the dosage and instructs the deep phosphorus removal agent dosing diaphragm pump to adjust the dosing flow rate.

2. The precise phosphorus removal and dosing method for a sewage treatment plant according to claim 1, characterized in that: The control device also includes a touch screen, an industrial switch and a host computer. The touch screen is electrically connected to the controller, and the host computer and the controller are electrically connected to the industrial switch respectively. The host computer and the controller are communicatively connected through the industrial switch networking. The controller is respectively connected to the water inlet lift pump, the intermediate lift pump, the carbon source dosing diaphragm pump, the deep dephosphorus agent dosing diaphragm pump and the biochemical pool dephosphorus agent dosing diaphragm pump through a frequency converter.

Images