Sewage treatment system capable of accurately removing phosphorus

Abstract

The utility model discloses a sewage treatment system capable of accurately removing phosphorus, and belongs to the technical field of sewage treatment. The system comprises a sand water pretreatment tank, a biological treatment tank, a secondary sedimentation tank, a water-collecting well, a coagulative precipitation tank, an online instrument and a dosing room, a total phosphorus and flow online monitor is mounted at the water-collecting well and transmits a detected total phosphorus value of effluent of the water-collecting well to a controller, and when a critical value is reached, the controller starts a metering diaphragm pump in the dosing room, so that the effluent of the water-collecting well flows out of the dosing room. And adding a corresponding amount of dephosphorization agent. The system is high in automation degree, the sewage treatment system is more stable, the usage amount of chemicals is saved to the maximum extent, chemical adding and phosphorus removal are more reasonable, and the labor and sewage operation cost is also reduced. The system is high in automation degree, the water outlet stability can be improved, and the problem that medicine adding lags is solved to the maximum extent; and the dosage can be controlled, so that the dosage of chemicals is saved to the greatest extent, the chemicals are more reasonably added to remove phosphorus, and the effects of reducing cost and increasing efficiency are realized.

Description

Technical Field

[0001] The utility model relates to a sewage treatment system for accurate phosphorus removal, belonging to the technical field of sewage treatment. Background Art

[0002] Phosphorus removal from wastewater is a systematic project. On the one hand, it is a treatment before adding the phosphorus removal agent. On the other hand, during the sewage treatment process, an appropriate amount of phosphorus removal agent needs to be added to the treated water to remove the total phosphorus in the treated water. The dosage of the phosphorus removal agent plays a vital role in ensuring that the water quality meets the discharge standards. Too small a dosage will affect the water treatment effect and cause the total phosphorus to exceed the standard; too large a dosage will cause unnecessary waste and increase costs. Since there are certain differences in the water volume and total phosphorus value of the treated water in different time periods, the required dosage also changes accordingly. How to accurately control the dosage is an important issue faced in practice. Utility Model Content

[0003] In order to solve the problems existing in the prior art, the utility model provides a precise automatic dosing system for phosphorus removal in sewage treatment, which adds chemical phosphorus removal agents according to the online monitoring value of total phosphorus in the water collection well, improves the stability of effluent, and solves the problem of hysteresis in drug addition to the greatest extent, making the sewage treatment system more stable; controlling the dosage of drugs, saving the use of drugs to the greatest extent, making the phosphorus removal by drug addition more reasonable, and also reducing manpower and sewage operation costs. The technical solution adopted by the utility model is: a sewage treatment system with precise phosphorus removal, in which the sewage outlet of the sand and water pretreatment tank is connected to the water inlet of the biological treatment tank, the water outlet of the biological treatment tank is connected to the water inlet of the secondary sedimentation tank, the water outlet of the secondary sedimentation tank is connected to the water collection well, and a water inlet grid is set at the water inlet of the water collection well, and the water collection well is connected to the water inlet of the coagulation sedimentation tank by a water pump through a water pumping pipe; an online flow monitor and an online total phosphorus monitor are set on the water pumping pipe;

[0004] The system also includes a dosing room, which is connected to the dosing port of the coagulation sedimentation tank by a pipeline after passing through a metering diaphragm pump;

[0005] The system also includes a controller, which is electrically connected to an online flow monitor, an online total phosphorus monitor, and a metering diaphragm pump.

[0006] A sand filter grid is arranged at the sewage inlet of the sand and water pretreatment tank, a screw conveyor is arranged at the bottom of the sand and water pretreatment tank, and a sand outlet is arranged at the end of the screw conveyor.

[0007] The coagulation sedimentation tank is divided into a flocculation zone and a sedimentation zone by a permeable plate, and a stirrer is arranged in the flocculation zone.

[0008] The permeation plate is provided with permeation holes, which are shrinkage holes with apertures gradually decreasing from top to bottom.

[0009] The beneficial effects of the utility model are as follows: the system includes a sand and water pretreatment tank, a biological treatment tank, a secondary sedimentation tank, a water collection well, a coagulation sedimentation tank, an online instrument, and a dosing room. The treatment of the sand and water pretreatment tank, the biological treatment tank, and the secondary sedimentation tank facilitates the subsequent detection of the total phosphorus amount. An online monitor for total phosphorus and flow is installed at the water collection well, and the total phosphorus value of the water outlet of the water collection well detected is transmitted to the controller. If the total phosphorus value of the effluent reaches above 0.3 mg / L, that is, it reaches the critical value of the total phosphorus value, the controller turns on the metering diaphragm pump in the dosing room and adds a dephosphorizer. The system has a high degree of automation, the sewage treatment system is more stable, the use of chemicals is saved to the maximum extent, making the dosing of phosphorus removal more reasonable, and also reducing manpower and sewage operation costs. The system can improve the stability of the effluent and solve the problem of hysteresis in the dosing to the maximum extent; it can also control the amount of dosing, save the use of chemicals to the maximum extent, make the dosing of phosphorus removal more reasonable, and achieve cost reduction and efficiency improvement. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for describing the embodiments are introduced below.

[0011] Figure 1 This is a schematic diagram of a wastewater treatment system for precise phosphorus removal.

[0012] In the figure: 1. Sand and water pretreatment tank, 1a. Sewage inlet, 1b. Sewage outlet, 1c. Sand outlet, 1d. Screw conveyor, 1e. Sand filter grid, 2. Biological treatment tank, 3. Secondary sedimentation tank, 4. Collection well, 4a. Inlet grid, 4b. Water suction pipe, 4c. Water suction pump, 5. Coagulation sedimentation tank, 5a. Permeable plate, 5b. Permeable hole, 5c. Sedimentation area, 5d. Agitator, 5e. Dosing port, 5f. Flocculation area, 6. Online flow monitor, 7. Online total phosphorus monitor, 8. Controller, 9. Dosing room, 10. Metering diaphragm pump. DETAILED DESCRIPTION

[0013] The present invention is described below with reference to the accompanying drawings and specific implementation methods:

[0014] Figure 1A precise automatic dosing system for phosphorus removal agent for sewage treatment is shown, which includes a sand and water pretreatment tank 1, a biological treatment tank 2, a secondary sedimentation tank 3, a water collection well 4, a coagulation sedimentation tank 5, an online flow monitor 6, an online total phosphorus monitor 7, a controller 8, a dosing room 9 and a metering diaphragm pump 10. The sewage outlet 1b of the sand and water pretreatment tank 1 is connected to the water inlet of the biological treatment tank 2, a sand filter grid 1e is arranged at the sewage inlet 1a of the sand and water pretreatment tank 1, a screw conveyor 1d is arranged at the bottom of the sand and water pretreatment tank 1, and a sand outlet 1c is arranged at the end of the screw conveyor 1d. The water outlet of the biological treatment tank 2 is connected to the water inlet of the secondary sedimentation tank 3, and the water outlet of the secondary sedimentation tank 3 is connected to the water collection well 4. The water inlet grid 4a is set at the water inlet of the water collection well 4. The water collection well 4 is connected to the water inlet of the coagulation sedimentation tank 5 by the water pump 4c through the water pump pipe 4b; the water pump pipe 4b is provided with an online flow monitor 6 and an online total phosphorus monitor 7; the coagulation sedimentation tank 5 is divided into a flocculation area 5f and a sedimentation area 5c by a permeable plate 5a, and an agitator 5d is provided in the flocculation area 5f. The permeable plate 5a is provided with a permeable hole 5b, and its top diameter is larger than the bottom diameter. The system also includes a dosing room 9, which is connected to the dosing port 5e of the coagulation sedimentation tank 5 by a pipeline after passing through a metering diaphragm pump 10. The system also includes a controller 8, and the controller 8 is electrically connected to the online flow monitor 6, the online total phosphorus monitor 7, and the metering diaphragm pump 10.

[0015] When the above technical scheme is used, sewage enters the sand and water pretreatment tank 1 from the sewage inlet 1a, and is separated from the sand by the filter sand grid 1e. The separated sediment is transported to the sand outlet 1c by the screw conveyor 1d for discharge, and the separated sewage is discharged from the sewage outlet 1b into the biological treatment tank 2 for treatment. The sewage treated in the biological treatment tank 2 enters the secondary sedimentation tank 3 for sedimentation, and enters the water collection well 4 after sedimentation. The sewage in the water collection well 4 is pumped out by the water pump 4c and the water pipe 4b. The online flow monitor 6 set on the water pipe 4b detects the water flow, and the online total phosphorus monitor 7 monitors the total phosphorus content in the sewage. The online total phosphorus monitor 7 and the online flow monitor 6 transmit signals to the controller 8. The working conditions (as shown in Table 1) are pre-set in the controller 8 according to the accuracy of the online instrument and the total phosphorus value limit. If the total phosphorus value of the effluent is less than 0.3 mg / L, no medicine is added. If the total phosphorus value of the effluent reaches 0.3 mg / L or above, that is, reaches the critical value of the total phosphorus value, the controller 8 controls the metering diaphragm pump 10 to start, and adds the dephosphorizing agent in the dosing room 9 to the coagulation sedimentation tank 5. In the coagulation sedimentation tank 5, the agitator 5d is used to stir and flocculate the agent for dephosphorization. When the total phosphorus value of the water collection well is less than 0.3 mg / L, the dosing is stopped. For every 0.05 mg / L increase in the total phosphorus value, the controller controls the metering diaphragm pump 10 to increase the dephosphorizing agent dosage by 2.5 mg / L.

[0016] Table 1 Phosphorus removal agent dosage table under working conditions

[0017]

[0018]

[0019] The system has a high degree of automation, the sewage treatment system is more stable, the use of chemicals is saved to the maximum extent, the addition of chemicals to remove phosphorus is more reasonable, and the manpower and sewage operation costs are reduced.

[0020] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A sewage treatment system for accurate phosphorus removal, characterized by: In the system, the sewage outlet (1b) of the sand and water pretreatment tank (1) is connected to the water inlet of the biological treatment tank (2), the water outlet of the biological treatment tank (2) is connected to the water inlet of the secondary sedimentation tank (3), the water outlet of the secondary sedimentation tank (3) is connected to the water collection well (4), a water inlet grid (4a) is provided at the water inlet of the water collection well (4), and the water collection well (4) is connected to the water inlet of the coagulation sedimentation tank (5) via a water suction pipe (4b) and a water suction pump (4c); an online flow monitor (6) and an online total phosphorus monitor (7) are provided on the water suction pipe (4b); The system further comprises a dosing room (9), wherein the dosing room (9) is connected to a dosing port (5e) of a coagulation sedimentation tank (5) via a metering diaphragm pump (10); The system further comprises a controller (8), wherein the controller (8) is electrically connected to an online flow monitor (6), an online total phosphorus monitor (7), and a metering diaphragm pump (10).

2. A sewage treatment system for accurate phosphorus removal according to claim 1, characterized in that: A sand filter grid (1e) is provided at the sewage inlet (1a) of the sand and water pretreatment tank (1), a screw conveyor (1d) is provided at the bottom of the sand and water pretreatment tank (1), and a sand outlet (1c) is provided at the end of the screw conveyor (1d).

3. A sewage treatment system for accurate phosphorus removal according to claim 1, characterized in that: The coagulation sedimentation tank (5) is divided into a flocculation zone (5f) and a sedimentation zone (5c) by a permeable plate (5a), and a stirrer (5d) is provided in the flocculation zone (5f).

4. A sewage treatment system for accurate phosphorus removal according to claim 3, characterized in that: The permeation plate (5a) is provided with permeation holes (5b), and the permeation holes (5b) are shrinkage holes whose apertures gradually decrease from top to bottom.

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