Mode-adjustable sewage treatment system

Abstract

The utility model provides a mode-adjustable sewage treatment system and relates to the technical field of sewage treatment. The system comprises an anaerobic tank, an anoxic tank, a facultative tank, an aerobic tank and a sedimentation tank which are sequentially communicated, wherein a facultative tank aeration device and a facultative tank submersible stirrer are arranged in the facultative tank; the system further comprises a control unit and a water quality detector, and the control unit is arranged to open or close the facultative tank aeration device and the facultative tank submersible stirrer according to a detection signal of the water quality detector. According to the mode-adjustable sewage treatment system disclosed by the utility model, the facultative tank is arranged, and nitration reaction and denitrification reaction are flexibly switched and changed, so that the phenomenon of unstable effluent caused by unstable quality and quantity of inlet water and large fluctuation of the integrated sewage treatment equipment is effectively improved and promoted; the sewage treatment effluent is stable and meets the effluent quality requirement.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, specifically an adjustable wastewater treatment system. Background Technology

[0002] Equipment operation is one of the main methods of wastewater treatment. After wastewater is treated, the wastewater is effectively transformed into clean water.

[0003] The AAO process is currently the most widely used wastewater treatment process in the market. It is a commonly used secondary wastewater treatment process that simultaneously removes nitrogen and phosphorus. Wastewater and returned sludge first enter the anaerobic tank (DO<0.2mg / L) and are completely mixed. After a certain period of time (1-2h) of anaerobic decomposition, some BOD is removed, and some nitrogen-containing compounds are converted into N2 (denitrification) and released. The polyphosphate-accumulating microorganisms (polyphosphate bacteria, etc.) in the returned sludge release phosphorus to meet the bacteria's phosphorus requirements.

[0004] Then the wastewater flows into the anoxic tank (DO<=0.5mg / L). The denitrifying bacteria in the tank use the undecomposed carbon-containing organic matter in the wastewater as a carbon source to reduce the nitrate ions that flow back into the aerobic tank through internal circulation to N2 and release them.

[0005] Next, the wastewater flows into the aerobic tank (DO, 2-4 mg / L). The NH3-N (ammonia nitrogen) in the water undergoes nitrification to produce nitrate. At the same time, the organic matter in the water is oxidized and decomposed to provide energy for phosphorus-absorbing microorganisms. The microorganisms absorb phosphorus from the water, and the phosphorus enters the cell tissue and accumulates in the microorganisms. After sedimentation and separation, it is discharged from the system in the form of phosphorus-rich sludge.

[0006] However, due to the improvement of living environment and the increase in living standards, conventional sewage treatment processes are affected by water quality and quantity, resulting in the effluent from conventional sewage treatment processes not fully meeting their design expectations.

[0007] Against this backdrop, it is necessary to improve and optimize the existing treatment process for AAO wastewater treatment in order to solve the corresponding problems. Utility Model Content

[0008] The purpose of this invention is to solve the problem of unstable effluent from the AAO wastewater treatment process, mainly the unstable effluent quality and large fluctuations in TN, COD, and ammonia nitrogen levels. The invention aims to improve and optimize the AAO process and equipment, and provide an adjustable wastewater treatment system.

[0009] To achieve the above objectives, this utility model employs the following technical solution:

[0010] An adjustable wastewater treatment system includes an anaerobic tank, an anoxic tank, an anaerobic tank, an aerobic tank, and a sedimentation tank connected in sequence. A sludge return device is provided between the sedimentation tank and the anaerobic tank, and a nitrification liquid return device is provided between the aerobic tank and the anoxic tank. The anaerobic tank is equipped with an anaerobic tank aeration device and an anaerobic tank submersible mixer. The adjustable wastewater treatment system also includes a control unit and a water quality analyzer for detecting the effluent quality. The anaerobic tank aeration device, the anaerobic tank submersible mixer, and the water quality analyzer are respectively signal-connected to the control unit. The control unit is configured to turn the anaerobic tank aeration device and the anaerobic tank submersible mixer on or off according to the detection signal from the water quality analyzer.

[0011] Preferably, the aerobic tank is equipped with an aerobic tank aeration duct, and the aerobic tank aeration duct is connected to an aeration fan through an air supply pipe.

[0012] Preferably, the anaerobic tank aeration device includes an anaerobic tank aeration duct, which is connected to the air supply duct. An aeration solenoid valve is provided on the anaerobic tank aeration duct, and the aeration solenoid valve is signal-connected to the control unit.

[0013] Preferably, the water quality analyzer is located at the outlet of the sedimentation tank.

[0014] Preferably, the control unit is a PLC module.

[0015] Preferably, the sludge return device includes a sludge return pipe connected at both ends to the sedimentation tank and the anaerobic tank respectively, and a sludge return pump is provided on the sludge return pipe.

[0016] Preferably, the nitrification liquid reflux device includes a nitrification liquid reflux pipe connected at both ends to the aerobic tank and the anoxic tank respectively, and a nitrification liquid reflux pump is provided on the nitrification liquid reflux pipe.

[0017] Preferably, the anoxic pool is equipped with an ultrasonic interface instrument.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0019] 1. The adjustable wastewater treatment system of this utility model, by setting up an anoxic tank, allows for flexible switching between nitrification and denitrification reactions, effectively improving and enhancing the unstable effluent caused by the instability and large fluctuations in the influent water quality and quantity of the integrated wastewater treatment equipment, so that the treated wastewater effluent stably meets the effluent water quality requirements.

[0020] 2. The intelligent design of this adjustable-mode wastewater treatment system enables real-time monitoring of effluent quality and fully automatic control of the switching between nitrification and denitrification reaction modes in the anaerobic block, achieving adjustable operation modes. This results in unattended operation, intelligent control, and stable effluent quality. The newly added anaerobic block control system does not require a separate setup and can be shared with the existing AAO wastewater treatment control system; only the relevant control points and process flows for the anaerobic block need to be added. Attached Figure Description

[0021] Figure 1 This is a top view of the structure of this utility model.

[0022] Figure 2 This is a schematic diagram of the main structure of this utility model.

[0023] Explanation of reference numerals in the attached figures

[0024] 1-Anaerobic tank, 2-Anoxic tank, 3-Anoxic tank, 4-Aerobic tank, 5-Sedimentation tank, 6-Anoxic tank aeration pipe, 7-Anoxic tank submersible mixer, 8-Control unit, 9-Water quality analyzer, 10-Aerobic tank aeration pipe, 11-Air supply pipe, 12-Aeration blower, 13-Sludge return pipe, 14-Sludge return pump, 15-Nitrified liquor return pipe, 16-Nitrified liquor return pump. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model is described below with reference to specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the present utility model. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the present utility model.

[0026] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or a point connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0027] The following will combine Figure 1 and Figure 2 The present invention will be further described in detail below. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

[0028] An adjustable wastewater treatment system includes an anaerobic tank 1, an anoxic tank 2, an anaerobic tank 3, an aerobic tank 4, and a sedimentation tank 5 connected in sequence. A sludge return device is provided between the sedimentation tank 5 and the anaerobic tank 1, and a nitrification liquid return device is provided between the aerobic tank 4 and the anoxic tank 2. An anaerobic tank 3 is equipped with an anaerobic tank aeration device and an anaerobic tank submersible mixer 7. The adjustable wastewater treatment system also includes a control unit 8 and a water quality analyzer 9 for detecting the effluent quality. The anaerobic tank aeration device, the anaerobic tank submersible mixer 7, and the water quality analyzer 9 are respectively signal-connected to the control unit 8. The control unit 8 is configured to turn the anaerobic tank aeration device and the anaerobic tank submersible mixer 7 on or off according to the detection signal from the water quality analyzer 9.

[0029] In this embodiment of the adjustable wastewater treatment system, influent enters the system through the influent pipe on the anaerobic tank 1. In the anaerobic tank 1, the water flow and submersible agitator drive the anaerobic bacteria to degrade organic matter into volatile organic compounds such as organic acids and acetic acid, producing a large amount of nitrates. Simultaneously, ammonia nitrogen in the wastewater is converted into nitrates by ammonia-oxidizing bacteria. Once the retention time meets the design requirements, the wastewater flows into the next unit, the anoxic tank 2. In the anoxic tank 2, the water flow and submersible agitator drive the denitrifying bacteria to reduce nitrates into nitrogen gas. Meanwhile, due to the presence of organic matter under anoxic conditions, this organic matter is further degraded. Once the retention time meets the design requirements, the wastewater flows into the next unit, the facultative tank 3. The influent method of the facultative tank 3 is adjustable, and the influent method is designed to correspond to the effluent from the upstream denitrification zone.

[0030] The anoxic tank 3 accommodates both nitrification and denitrification reactions, and its operating mode and parameters can be flexibly adjusted. The water quality analyzer 9 is used to detect the quality of the effluent.

[0031] When the water quality analyzer 9 detects that the ammonia nitrogen in the effluent exceeds the standard, it indicates that the residence time in the nitrification reaction zone inside the wastewater treatment plant is insufficient and the indicators have not been fully degraded. The water quality analyzer 9 transmits the signal to the control unit 8. The control unit 8 controls the submersible mixer 7 in the anoxic tank to stop operating and the aeration device in the anoxic tank to start operating, supplying oxygen to the anoxic tank 3, adjusting the anoxic block to the nitrification zone, increasing the nitrification reaction time, and extending the nitrification reaction time of the wastewater treatment plant, so that the overall wastewater treatment effluent stably meets the effluent quality requirements.

[0032] When the water quality analyzer 9 detects that the total nitrogen in the effluent exceeds the standard, it indicates that the residence time in the denitrification reaction zone within the wastewater treatment plant is insufficient, and the pollutants have not been fully degraded. The water quality analyzer 9 transmits the signal to the control unit 8. The control unit 8, based on the detection signal from the water quality analyzer 9, controls the submersible mixer 7 in the anoxic tank to start operating, and the aeration device in the anoxic tank to stop operating. This adjusts the anoxic zone to a denitrification zone, increasing the denitrification reaction time and extending the wastewater treatment denitrification reaction time, ensuring that the treated wastewater consistently meets the effluent quality requirements. Through the flexible conversion of the anoxic zone, the nitrification and denitrification reactions lacking in the wastewater treatment process are strengthened, ensuring stable effluent compliance.

[0033] In this embodiment, the addition of the facultative anaerobic zone and the integration of the automatic control system transform the conventional wastewater treatment operation mode into an adjustable operation mode that can be adjusted, modified, and switched according to water quality conditions, making the wastewater treatment system effluent more stable, efficient, and reliable.

[0034] It should be noted that the water quality detector, control unit and other components in the control system of this embodiment, as well as the control system formed by connecting these components, are all existing technologies. This embodiment will not elaborate on the specific structure, principle, specific connection of each component and the control principle of the system.

[0035] In some embodiments, the aerobic tank 4 is provided with an aerobic tank aeration duct 10, which is connected to an aeration fan 12 via an air supply pipe 11. The aeration duct is existing technology and will not be described in detail in this embodiment. The facultative tank aeration device includes a facultative tank aeration duct 6, which is connected to the air supply pipe 11. The aeration fan 12 can simultaneously supply oxygen to the facultative tank 3. An aeration solenoid valve is provided on the facultative tank aeration duct 6, which is signal-connected to the control unit 8. The control unit 8 controls the start and stop of aeration in the facultative tank 3 by controlling the opening and closing of the solenoid valve.

[0036] Specifically, the water quality testing instrument 9 is located at the outlet of the sedimentation tank 5.

[0037] In some embodiments, the control unit 8 may be a PLC module.

[0038] Specifically, the sludge return device includes a sludge return pipe 13 connected at both ends to the sedimentation tank 5 and the anaerobic tank 1, respectively, and a sludge return pump 14 is installed on the sludge return pipe 13. The nitrification liquor return device includes a nitrification liquor return pipe 15 connected at both ends to the aerobic tank 4 and the anoxic tank 2, respectively, and a nitrification liquor return pump 16 is installed on the nitrification liquor return pipe 15. Sludge return and digestate return are both existing technologies and will not be described in detail in this embodiment.

[0039] Furthermore, the anoxic tank 3 is equipped with an ultrasonic interface instrument to monitor the water level in the anoxic tank 3, thereby controlling the water level.

[0040] The above embodiments are merely illustrative examples of this patent and do not limit its scope of protection. Those skilled in the art can make partial changes to them, as long as they do not exceed the spirit and essence of this patent, they are all within the scope of protection of this patent.

Claims

1. A wastewater treatment system with adjustable modes, characterized in that, The system includes an anaerobic tank (1), an anoxic tank (2), an anaerobic tank (3), an aerobic tank (4), and a sedimentation tank (5) connected in sequence. A sludge return device is provided between the sedimentation tank (5) and the anaerobic tank (1). A nitrification liquid return device is provided between the aerobic tank (4) and the anoxic tank (2). An anaerobic tank aeration device and an anaerobic tank submersible mixer (7) are provided in the anaerobic tank (3). The adjustable wastewater treatment system also includes a control unit (8) and a water quality analyzer (9) for detecting the effluent quality. The anaerobic tank aeration device, the anaerobic tank submersible mixer (7), and the water quality analyzer (9) are respectively connected to the control unit (8). The control unit (8) is set to open or close the anaerobic tank aeration device and the anaerobic tank submersible mixer (7) according to the detection signal of the water quality analyzer (9).

2. The adjustable-mode wastewater treatment system according to claim 1, characterized in that: The aerobic tank (4) is equipped with an aerobic tank aeration pipe (10), and the aerobic tank aeration pipe (10) is connected to an aeration fan (12) through an air supply pipe (11).

3. The adjustable-mode wastewater treatment system according to claim 2, characterized in that: The anaerobic pool aeration device includes an anaerobic pool aeration duct (6), which is connected to the air supply duct (11). An aeration solenoid valve is provided on the anaerobic pool aeration duct (6), and the aeration solenoid valve is signal-connected to the control unit (8).

4. The adjustable-mode wastewater treatment system according to claim 1, characterized in that: The water quality testing instrument (9) is located at the outlet of the sedimentation tank (5).

5. The adjustable-mode wastewater treatment system according to claim 1, characterized in that: The control unit (8) is a PLC module.

6. The adjustable-mode wastewater treatment system according to claim 1, characterized in that: The sludge return device includes a sludge return pipe (13) connected at both ends to the sedimentation tank (5) and the anaerobic tank (1) respectively, and a sludge return pump (14) is provided on the sludge return pipe.

7. The adjustable-mode wastewater treatment system according to claim 1, characterized in that: The nitrification liquid reflux device includes a nitrification liquid reflux pipe (15) connected at both ends to the aerobic tank (4) and the anoxic tank (2) respectively, and a nitrification liquid reflux pump (16) is provided on the nitrification liquid reflux pipe.

8. The adjustable-mode wastewater treatment system according to claim 1, characterized in that: The anoxic pool (3) is equipped with an ultrasonic interface instrument.

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