A sewage treatment CASS pool decanting level monitoring system

Abstract

This utility model discloses a wastewater treatment CASS tank decanting level monitoring system, including infrared light emitting light source modules and light source intensity sensing modules symmetrically arranged on both sides of the CASS tank, and a computer processing system. The computer processing system is connected to both the infrared light emitting light source modules and the light source intensity sensing module via output signals. The computer processing system controls the on / off state of the infrared light emitting light source modules and adjusts the emission of infrared light through output signals. The light source intensity sensing module receives the infrared light emitted by the infrared light emitting light source modules and outputs an infrared light intensity signal. The computer processing system is connected to the decanter via signals to monitor and regulate the decanting depth of the decanter. This utility model's decanting level monitoring system provides accurate data, reliable operation, and a high degree of automation, and has broad application prospects.

Description

Technical Field

[0001] This utility model belongs to the field of wastewater treatment technology, specifically relating to a wastewater treatment CASS tank decanting level monitoring system. Background Technology

[0002] In wastewater treatment processes, activated sludge biological treatment is the core and key process for pollutant removal, efficiently removing 80%-90% of pollutants such as ammonia nitrogen, total nitrogen, and total phosphorus from wastewater. Process types include circulating activated sludge (CASS), anaerobic-anoxic-aerobic (A2O) processes, and oxidation ditch processes. Among these, towns or regions with wastewater volumes below 20,000 m³ / d typically employ the circulating activated sludge process (CASS). Its main advantages are its simple process flow, sequential batch processing of wastewater, and completion of the influent, aeration, sedimentation, and decanting processes within a single tank, eliminating the need for secondary sedimentation tanks, reducing land area requirements, and lowering investment costs.

[0003] The Circulating Activated Sludge System (CASS) utilizes the growth and metabolism of activated sludge microorganisms to convert pollutants in wastewater into substances such as carbon dioxide and nitrogen. After the reaction is complete, aeration is stopped, sedimentation occurs, and then the supernatant is discharged through a decanter before further wastewater treatment. Effluent from the CASS tank is achieved by slowly lowering the decanter at the end of the tank. To prevent sludge discharge from the decanter, existing wastewater treatment plants typically install video monitoring systems in the CASS tank, transmitting images back to the control room where administrators start and stop the decanter. However, in actual surveys, it was found that when odor collection hoods or insulated sheds are installed above the CASS tank in wastewater treatment plants, the ambient temperature is lower than the wastewater temperature in winter, causing heat to accumulate inside these hoods or sheds. This results in blurry video footage and difficulty in determining the decanting height. Utility Model Content

[0004] The purpose of this invention is to provide a wastewater treatment CASS tank decanting level monitoring system, which solves the technical problems of poor adaptability and inaccurate monitoring in existing decanting monitoring devices.

[0005] The technical solution adopted in this utility model is: a wastewater treatment CASS tank decanting level monitoring system, including an infrared light emitting light source module and a light source intensity sensing module symmetrically arranged on both sides of the CASS tank, and a computer processing system. The computer processing system is connected to the infrared light emitting light source module and the light source intensity sensing module respectively. The computer processing system controls the on / off state of the infrared light emitting light source module and adjusts the emission of infrared light through output signals. The light source intensity sensing module is used to receive the infrared light emitted by the infrared light emitting light source module and output the infrared light intensity signal. The computer processing system is connected to the decanter through signals to monitor and regulate the decanting depth of the decanter.

[0006] The beneficial effects of this utility model are as follows: Compared with the prior art, this utility model provides a brand-new CASS pool decanting level monitoring system. By designing symmetrical infrared light emitting light source modules and light source intensity sensing modules on both sides of the CASS pool, it is used to detect the infrared light emission intensity. Then, the computer processing system converts and processes the refraction and reflection phenomena of infrared light and displays a curve of the corresponding light source depth and the percentage of infrared light received brightness to guide the descent height of the decanter. This CASS pool decanting level monitoring system can accurately monitor and control the decanting depth of the decanter, and has strong adaptability and reliable operation.

[0007] The present invention is further characterized in that, Furthermore, both the infrared light emission source module and the light source intensity sensing module are arranged below the horizontal water surface of the maximum water level control line in the CASS pool.

[0008] Furthermore, both the infrared light emission source module and the light source intensity sensing module are arranged in the aeration zone of the CASS pool.

[0009] Furthermore, the installation length of both the infrared light emitting source module and the light source intensity sensing module does not exceed the maximum water level control line of the CASS pool.

[0010] Furthermore, the infrared light emitting source module includes several vertically arranged infrared light sources, and the light source intensity sensing module includes several vertically arranged light sensors.

[0011] Furthermore, the interval between two adjacent infrared light sources is 5-15cm.

[0012] Furthermore, the interval between two adjacent light sensors is 5-15cm.

[0013] Furthermore, both the infrared light emitting light source module and the light source intensity sensing module have semi-circular waterproof shells.

[0014] Furthermore, both the infrared light emitting light source module and the light source intensity sensing module are mounted on both sides of the CASS pool via sliding rail brackets.

[0015] Furthermore, the computer processing system includes a PLC control module for processing infrared light intensity signals and another remotely connected computer to remotely turn the monitoring system on / off. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a wastewater treatment CASS tank decanting level monitoring system.

[0017] In the diagram, 1. Infrared light emitting light source module, 2. Light source intensity sensing module, 3. CASS pool, 4. Computer processing system. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0019] This utility model's decanting level monitoring system is primarily designed for the decanting process in CASS (Cyclic Activated Sludge System) tanks in wastewater treatment. The CASS tank is a reaction tank for a circulating activated sludge system, also known as CAST (Cyclic Activated Sludge System), which is a circulating activated sludge process. This process integrates aeration and sedimentation functions, and the operation involves sequential aeration, sedimentation, and drainage within the same tank, in a cyclical manner. It eliminates the need for a secondary sedimentation tank in conventional activated sludge processes, resulting in a smaller footprint and lower investment. However, during the drainage process, i.e., the decanting stage, a video monitoring system is typically installed in the CASS tank to monitor the sludge decanting depth. Then, management personnel in the central control room manually operate the decanter to lower its height or start / stop it. In winter, when the outdoor temperature is lower than that of the sewage treatment plant, heat rises inside the plant, causing the video monitoring system to produce blurry images. This makes it impossible for management personnel to see the decanting depth clearly, indicating that the existing decanting system has technical problems such as poor adaptability and inaccurate decanting depth monitoring.

[0020] Currently, there are two other types of sludge level monitoring devices on the market: one is an ultrasonic sludge level meter, which emits energy waves, i.e., pulse signals, through a device that can emit energy waves. When the energy waves encounter obstacles, they are reflected, and the reflected signals are received by a receiving device. However, this device is suspended above the pool and is easily interfered with by the floating layer of sludge, making its operation unreliable. The other is an optical probe float-type measuring device, which submerges an optical sensor underwater and moves up and down from the water surface to the bottom of the pool to measure the sludge concentration at each depth. When the sensor moves up and down, it will cause local disturbances in the water flow, causing the sludge to float and resulting in a decrease in the sludge depth.

[0021] When the decanting height does not reach the clear water height, it will affect the influent volume of the next stage of wastewater treatment and disrupt the normal wastewater treatment cycle. When the decanting height exceeds the clear water height, activated sludge from the CASS tank will be discharged. This discharge reduces the sludge concentration in the CASS tank, affecting its nitrogen, phosphorus, and organic matter removal efficiency. Furthermore, it increases the load on the subsequent high-efficiency sedimentation tank in the advanced treatment process, impacting the effluent SS concentration and clarity. Therefore, this invention aims to provide a CASS tank decanting level monitoring system that is highly adaptable, has high monitoring accuracy, and is easy to operate.

[0022] The main concept of this utility model is as follows: by symmetrically designing infrared light emitting light source modules and light source intensity sensing modules on both sides of the CASS pool, and utilizing the characteristic that infrared light will be refracted and reflected when it encounters obstacles, the infrared light intensity signal that can be received by the light source intensity sensing module is input to the computer processing system. The computer processing system converts the infrared light intensity signal into the percentage of infrared light received brightness W, and generates a curve with W on the horizontal axis and H on the vertical axis based on the corresponding light source depth H. The generated curve is displayed in the computer processing system to guide the decanting depth of the decanter.

[0023] Based on the above basic concept, the following are different embodiments for illustration: In one embodiment, the present invention provides a wastewater treatment CASS tank decanting level monitoring system, such as... Figure 1As shown, the system includes an infrared light emitting module 1 and a light intensity sensing module 2 symmetrically arranged on both sides of the CASS pool 3. The symmetrical design of the infrared light emitting module 1 and the light intensity sensing module 2 ensures that all infrared light emitted by the infrared light emitting module 1 is emitted to the light intensity sensing module 2 without sludge obstruction. When the infrared light is in the sludge fluff layer, some of the infrared light is refracted and reflected on the floating sludge surface, causing partial attenuation of the light intensity. When the infrared light is in the deposited sludge layer, all the infrared light is refracted and reflected, causing complete attenuation of the light intensity. This process utilizes the principle of refraction and reflection of infrared light when it encounters obstacles to monitor the decanting level. This practical decanting level monitoring system also includes a computer processing system 4, which is connected to the infrared light emitting module 1 and the light intensity sensing module 2 respectively. The computer processing system 4 outputs signals... The infrared light emitting module 1 controls the on / off state and adjusts the emission of infrared light. During sewage treatment in the CASS tank 3, the processes of influent, aeration, sedimentation, and decanting are carried out sequentially. When the sedimentation cycle of the CASS tank is completed, the computer processing system 4 issues a command to start the decanting level monitoring system of this utility model and adjusts the infrared light emitted by the infrared light emitting module 1. The light source intensity sensing module 2 is used to receive the infrared light emitted by the infrared light emitting module 1 and output the infrared light intensity signal. The light source intensity sensing module 2 outputs the received infrared light to the computer processing system 4 in the form of an infrared light intensity signal. The computer processing system 4 converts the infrared light intensity signal into the percentage of infrared light received brightness and displays it on the computer processing system 4 as a curve based on the corresponding light source depth and the percentage of infrared light received brightness. The computer processing system 4 is connected to the decanter through a signal to monitor and control the decanting depth of the decanter. In this embodiment, the state of the decanting level is reflected by the principle of light refraction and reflection, and the computer processing system performs accurate calculations and conversions, enabling the decanting level monitoring system of this utility model to accurately monitor and regulate the decanting depth. It is highly automated, reliable in operation, and suitable for different temperature environments, thus improving the adaptability of the decanting level monitoring system.

[0024] In one embodiment, both the infrared light emitting source module 1 and the light source intensity sensing module 2 are arranged below the transverse water surface of the maximum water level control line in the CASS tank 3. The maximum water level control line typically refers to the highest liquid level reached by the reaction tank at the end of the influent process. Controlling the maximum water level helps prevent overflow, ensures sufficient residence time, and optimizes the sedimentation effect. Placing the infrared light emitting source module 1 and the light source intensity sensing module 2 below the transverse water surface of the maximum water level control line facilitates monitoring after the sedimentation process is completed.

[0025] To make monitoring more accurate after sedimentation, this utility model provides a preferred embodiment in which the infrared light emitting light source module 1 and the light source intensity sensing module 2 are both arranged in the aeration zone of the CASS tank 3. The area of ​​the aeration zone accounts for more than 70% of the area of ​​the CASS tank 3. The sludge is mixed evenly, the sludge sedimentation level monitoring is more representative, and the monitoring data is more accurate. Therefore, the infrared light emitting light source module 1 and the light source intensity sensing module 2 are designed in the aeration zone of the CASS tank 3.

[0026] The water level in CASS pool 3 is dynamically changing, and the maximum water level control line is a safety upper limit set by the system. In one embodiment, if the installation length of the infrared light emitting light source module 1 and the light source intensity sensing module 2 exceeds the maximum water level control line of the CASS pool, then the infrared light emitting light source module 1 and the light source intensity sensing module 2 cannot be completely submerged in the water, and the unsubmerged parts cannot monitor water quality. Therefore, this application provides a more preferred embodiment in which the installation length of both the infrared light emitting light source module 1 and the light source intensity sensing module 2 does not exceed the maximum water level control line of CASS pool 3. By setting the installation length of the infrared light emitting light source module 1 and the light source intensity sensing module 2 within the range of the maximum water level control line, it is ensured that the infrared light emitting light source module 1 and the light source intensity sensing module 2 can always be submerged in water for continuous and stable water quality monitoring. At the same time, it also prevents the infrared light emitting light source module 1 and the light source intensity sensing module 2 from being exposed to the air during the decanting process, which could lead to equipment failure due to drying out.

[0027] In one embodiment, the infrared light emitting source module 1 includes several infrared light sources arranged in a vertical array. The interval between two adjacent infrared light sources is 5-15cm. In this embodiment, the infrared light emitting source module 1 is designed as multiple, equally spaced, vertically arrayed infrared light sources. The purpose is to ensure that the infrared light emitted by the infrared light emitting source 1 can form a light curtain uniformly and continuously, ensuring more accurate monitoring. At the same time, setting the interval to 5-15cm is to prevent two adjacent emitting sources from being too close, causing the emitted infrared light to overlap and resulting in signal interference, which would affect the light source sensor 2's perception and judgment of changes in light intensity in a specific area. Furthermore, this application provides a more preferred embodiment in which the interval between two adjacent infrared light sources is 10cm. When the interval is 10cm, the infrared light emitted by two adjacent infrared light sources will neither overlap nor have gaps, resulting in the optimal monitoring results.

[0028] Based on the description of the above embodiments, the light source intensity sensing module 2 in this embodiment includes several vertically arrayed light sensors, with a spacing of 5-15 cm between two adjacent light sensors. In this embodiment, the light source intensity sensing module 2 is also designed as multiple, equally spaced, vertically arrayed light sensors. This is to ensure comprehensive and complete reception of the infrared light emitted by the infrared light emitting module 1, and to comprehensively monitor the infrared light intensity signals of the upper clear water layer, the middle layer with suspended sludge, and the bottom sludge layer, thereby improving the accuracy of the monitoring data. Furthermore, this application provides a more preferred embodiment where the spacing between two adjacent light sensors is 10 cm.

[0029] In one embodiment, both the infrared light emitting source module 1 and the light source intensity sensing module 2 have semi-circular waterproof housings. The semi-circular and waterproof design of the housings of the infrared light emitting source module 1 and the light source intensity sensing module 2 in this embodiment is to adapt to the harsh environment of the CASS pool, which is filled with water, sludge, and chemicals. The semi-circular waterproof housing effectively prevents the intrusion of sewage and corrosive chemicals, protecting the internal circuitry and optical components of the infrared light emitting source module 1 and the light source intensity sensing module 2 from damage, extending the service life of the equipment, enabling continuous and stable operation, and improving the reliability of the decanting level monitoring system of this application.

[0030] In one embodiment, the infrared light emitting light source module 1 and the light source intensity sensing module 2 are fixedly designed on both sides of the CASS pool 2, causing them to be immersed in sewage for a long time. Sludge and chemicals in the sewage adhere to the surfaces of the infrared light emitting light source module 1 and the light source intensity sensing module 2, resulting in a decrease in the intensity of both the infrared light emitted by the infrared light emitting light source module 1 and the infrared light received by the light source intensity sensing module 2, thus reducing the monitoring results. Therefore, this application provides a more preferred embodiment in which both the infrared light emitting light source module 1 and the light source intensity sensing module 2 are mounted on both sides of the CASS pool 3 via sliding rail brackets. In this embodiment, by designing the brackets for the infrared light emitting light source module 1 and the light source intensity sensing module 2 as sliding rail brackets, the infrared light emitting light source module 1 and the light source intensity sensing module 2 are slid down to the limited water level via the sliding rail brackets 30 minutes before the end of the sedimentation cycle. This effectively avoids the infrared light emitting light source module 1 and the light source intensity sensing module 2 being in a harsh environment for a long time, keeps the infrared light emitting light source module 1 and the light source intensity sensing module 2 clean, keeps them in the best condition, and prevents the emitted light source from attenuating and the received signal from weakening.

[0031] In one embodiment, the computer processing system 4 includes a PLC control module for processing infrared light intensity signals and another remotely connected computer for remotely turning the monitoring system on / off. The PLC control module converts the infrared light intensity signal received by the light source intensity sensing module 2 into an infrared light reception brightness percentage W, and generates a curve with W on the horizontal axis and H on the vertical axis based on the corresponding light source depth H. The other computer, through remote access, enables remote turning of the monitoring device on / off, data transmission, and curve display. This structural design improves the automation level of the decaying level monitoring system of this invention and makes the monitoring data more accurate.

[0032] After the CASS tank 3 completes the sedimentation cycle, the computer processing system 4 of the decanting level monitoring system of this utility model is turned on. The PLC control module outputs a signal to control the vertically arrayed infrared light emitting light source to emit monochromatic red light. The light source intensity sensing module 2 receives and processes the light source intensity signal. The PLC calculation module calculates the curve of the light source depth H and the percentage of infrared light received brightness W, which is displayed on another computer in the sewage treatment plant.

[0033] When the light source depth H ≤ 0.7m, the percentage of infrared light received is > 90%; When the light source depth is 0.7 < H ≤ 0.9 m, the percentage of infrared light received is 70% < W < 90%. When the light source depth is 0.9 < H ≤ 1.0 m, the percentage of infrared light received is 40% < W < 70%; When the light source depth H > 1.0m, the percentage of infrared light received is W < 40%.

[0034] The mud level monitoring results indicate that the maximum height reduction limit for the decanter is 0.9m.

[0035] This invention relates to a sedimentation level monitoring system for a wastewater treatment CASS tank. The system is activated when sedimentation is complete and decanting is about to begin. It uses a fixed infrared emitter and a light source to detect the intensity of the light source, completing sedimentation in just 5 minutes. This information guides the decanter to lower its height. The system provides accurate data, reliable operation, and a high degree of automation, making it suitable for a wide range of applications.

Claims

1. A sewage treatment CASS tank decanting level monitoring system, characterized in that, The system includes an infrared light emitting light source module (1) and a light source intensity sensing module (2) symmetrically arranged on both sides of the CASS pool (3), and a computer processing system (4). The computer processing system (4) is connected to the infrared light emitting light source module (1) and the light source intensity sensing module (2) respectively. The computer processing system (4) controls the switching state of the infrared light emitting light source module (1) and adjusts the emission of infrared light by outputting signals. The light source intensity sensing module (2) is used to receive the infrared light emitted by the infrared light emitting light source module (1) and output the infrared light intensity signal. The computer processing system (4) is connected to the decanter by signal to monitor and regulate the decanter's decanting depth.

2. The decanting position monitoring system according to claim 1, characterized in that Both the infrared light emitting light source module (1) and the light source intensity sensing module (2) are arranged below the horizontal water surface of the maximum water level control line of the CASS pool (3).

3. The decanting position monitoring system according to claim 2, characterized in that Both the infrared light emitting light source module (1) and the light source intensity sensing module (2) are arranged in the aeration zone of the CASS pool (3).

4. The decanting position monitoring system according to claim 3, characterized in that The installation length of both the infrared light emitting light source module (1) and the light source intensity sensing module (2) does not exceed the maximum water level control line of the CASS pool (3).

5. The decanting position monitoring system according to claim 4, characterized in that The infrared light emitting light source module (1) includes several infrared light sources arranged in a vertical array, and the light source intensity sensing module (2) includes several light sensors arranged in a vertical array.

6. The decanting position monitoring system according to claim 5, characterized in that The interval between two adjacent infrared light sources is 5-15cm.

7. The decanting position monitoring system according to claim 5, wherein The interval between two adjacent light sensors is 5-15 cm.

8. The decanting position monitoring system according to any one of claims 1 to 7, characterized in that The outer shells of the infrared light emitting light source module (1) and the light source intensity sensing module (2) are both semi-circular waterproof shells.

9. The decanting position monitoring system according to claim 8, characterized in that The infrared light emitting light source module (1) and the light source intensity sensing module (2) are both mounted on both sides of the CASS pool (3) via sliding rail brackets.

10. The decanting position monitoring system according to claim 1, characterized in that, The computer processing system (4) includes a PLC control module for processing the infrared light intensity signal and another computer that is remotely connected to remotely turn the monitoring system on / off.

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