Sewage treatment system and method of operating the sewage treatment system

Abstract

The object of the present invention is to provide a sewage treatment system and an operating method for a sewage treatment system that can take measures to suppress the deterioration of treated water quality in response to fluctuations in the amount of sewage inflow to be treated, without delay. [Solution] To solve the above problems, a sewage treatment system and a method for operating this system are provided, comprising: a sewage treatment unit for receiving and treating sewage; an inflow volume prediction means for predicting the amount of water flowing into the sewage treatment unit; and an SS outflow suppression means for reducing the amount of suspended solids outflow into the treated water before the scheduled time of increase in the inflow volume predicted by the inflow volume prediction means. According to this invention, it is possible to take measures to suppress the deterioration of treated water quality in response to fluctuations in the amount of wastewater inflow without delay.

Description

Technical Field

[0001] The present invention relates to a sewage treatment system and an operation method of the sewage treatment system.

Background Art

[0002] Generally, the combined sewage and rainwater discharged from households, factories, etc. are introduced as sewage into facilities related to sewage treatment (sewage treatment plants, final treatment plants), treated, and finally discharged into rivers. The amount and quality of sewage flowing into facilities related to sewage treatment vary not only with the increase and decrease of the amount of sewage discharged from households, factories, etc., but also due to weather (such as rainfall). On the other hand, since the treated sewage (treated water) is finally discharged into rivers, it is necessary to maintain a predetermined treated water quality. For this reason, in the operation of facilities related to sewage treatment, it is necessary to take measures according to the fluctuations in the amount or quality of the inflowing sewage (in other words, load fluctuations), and particularly measures corresponding to the increase in the amount of sewage due to rainfall, etc. are required.

[0003] For example, Patent Document 1 describes a treatment apparatus including an anaerobic tank, an aerobic tank, and a sedimentation tank, which takes into account measures against load fluctuations in the treatment of wastewater such as sewage. A buffer tank is provided in parallel with the anaerobic tank, and the diversion ratio of the wastewater flowing into the buffer tank and the anaerobic tank is determined according to the progress of the nitrification reaction in the aerobic tank.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As shown in Patent Document 1, various measures have been taken to address load fluctuations on sewage treatment facilities (such as an increase in the amount of sewage flowing in). On the other hand, in recent years, localized and concentrated rainfall has been increasing, and situations in which the amount of sewage flowing into sewage treatment facilities increases rapidly are occurring frequently. As shown in Patent Document 1, measures based on information regarding fluctuations in water volume or water quality within the treatment facility may not be sufficient to respond in time, potentially leading to a deterioration in the quality of treated water.

[0006] Furthermore, localized, concentrated rainfall may cause the amount of wastewater treated at sewage treatment facilities to exceed the planned treatment volume. Even in such cases, however, it is necessary to continue accepting sewage at the facilities without suspending operations, and to implement measures to suppress the deterioration of treated water quality.

[0007] The object of the present invention is to provide a sewage treatment system and a method for operating a sewage treatment system that can respond without delay to fluctuations in the amount of sewage inflow to be treated, thereby suppressing the deterioration of treated water quality. [Means for solving the problem]

[0008] As a result of diligent study on the above-mentioned problems, the inventors of the present invention have found that in sewage treatment, by predicting the amount of sewage inflow to be treated, and focusing on the timing of the increase in the amount of sewage inflow obtained from the prediction results, and by implementing means to suppress the deterioration of the water quality of treated water, it is possible to respond to fluctuations in the amount of sewage inflow without delay in suppressing the deterioration of treated water quality, and have completed the present invention. In other words, the present invention relates to the following sewage treatment system and method for operating the sewage treatment system.

[0009] The present invention, which solves the above problems, is characterized by comprising: a sewage treatment unit for receiving and treating sewage; an inflow volume prediction means for predicting the amount of water flowing into the sewage treatment unit; and an SS outflow suppression means for reducing the amount of suspended solids outflow into the treated water before the scheduled time of increase in the inflow volume predicted by the inflow volume prediction means. The wastewater treatment system of the present invention predicts the amount of wastewater to be treated (inflow volume) flowing into the wastewater treatment section, which receives and treats the wastewater. Based on the prediction, measures are taken to suppress the outflow of suspended solids into the treated water as a means of suppressing the deterioration of the treated water quality before the expected time when the inflow volume is expected to increase. This makes it possible to respond to fluctuations in the inflow volume of wastewater without delay in order to suppress the deterioration of the treated water quality.

[0010] Furthermore, in one embodiment of the sewage treatment system of the present invention, the inflow volume prediction means is characterized by predicting the inflow volume to the sewage treatment unit within one hour. This feature makes it possible to accurately grasp the trend of load fluctuations on the sewage treatment system within a short period of time, and to secure the time required to respond to load fluctuations. In particular, even in the case of rapid load fluctuations caused by localized, concentrated rainfall, it becomes easier to proceed without delay in taking measures to suppress the deterioration of treated water quality.

[0011] Furthermore, in one embodiment of the sewage treatment system of the present invention, the inflow volume prediction means is characterized by predicting the amount of water flowing into the sewage treatment unit based on actual values ​​of the amount of water flowing into the sewage treatment unit and weather-related data. This feature enables rapid and highly accurate prediction of inflow volume, allowing for more reliable and timely responses to fluctuations in sewage inflow volume to suppress the deterioration of treated water quality.

[0012] Furthermore, in one embodiment of the wastewater treatment system of the present invention, the SS outflow suppression means is characterized by including the addition of chemicals and / or stopping aeration in the wastewater treatment section. This feature allows for the promotion of SS sedimentation in the sewage treatment area or the maintenance of SS sedimentation before the scheduled time of increased inflow, by performing operations that exert a relatively rapid effect on SS sedimentation, such as adding chemicals or stopping aeration, before the inflow rate increases. As a result, even if the inflow rate to the sewage treatment area increases, it becomes possible to minimize the outflow of SS into the treated water, and consequently, to proceed without delay in measures to suppress the deterioration of treated water quality.

[0013] Furthermore, one embodiment of the sewage treatment system of the present invention is characterized by having a display means that displays an alarm or work instruction based on information obtained by an inflow volume prediction means. This feature makes it easier to streamline maintenance and optimize the operation of the sewage treatment system by transmitting warnings and work instructions to workers based on predicted inflow volume, thereby enabling timely responses to suppress the deterioration of treated water quality in response to fluctuations in sewage inflow volume.

[0014] The present invention provides a method for operating a sewage treatment system to solve the above problems, comprising: a sewage treatment step of receiving and treating sewage in the sewage treatment unit; an inflow rate prediction step of predicting the amount of water flowing into the sewage treatment unit; and an SS outflow suppression step of reducing the amount of suspended solids outflow into the treated water before the time of expected increase in the inflow rate predicted in the inflow rate prediction step. The present invention relates to a wastewater treatment system operating method that includes a wastewater treatment section for receiving and treating wastewater. This method involves predicting the amount of wastewater to be treated that flows into the wastewater treatment section (inflow volume), and reducing the amount of suspended solids released into the treated water in order to suppress the deterioration of the treated water quality before the time when the inflow volume is expected to increase based on the prediction results. This makes it possible to take measures to suppress the deterioration of treated water quality in response to fluctuations in the inflow volume of wastewater without delay. [Effects of the Invention]

[0015] According to the present invention, in sewage treatment, it is possible to provide a sewage treatment system and an operation method of the sewage treatment system that can respond without delay to fluctuations in the inflow water volume of sewage to be treated to suppress a decrease in treated water quality.

Brief Description of the Drawings

[0016] [Figure 1] FIG. 1 is a schematic explanatory view showing the structure of a sewage treatment system in an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing a process related to the prediction of the inflow water volume by the inflow water volume prediction means provided in the sewage treatment system in an embodiment of the present invention.

Mode for Carrying Out the Invention

[0017] Hereinafter, embodiments of the sewage treatment system and the operation method of the sewage treatment system according to the present invention will be described in detail with reference to the drawings. Note that the operation method of the sewage treatment system of the present invention shall be replaced by the following description of the structure and operation of the sewage treatment system. In addition, the sewage treatment system and the operation method of the sewage treatment system described in the embodiments are merely examples for explaining the sewage treatment system and the operation method of the sewage treatment system according to the present invention, and are not limited thereto.

[0018] 〔Sewage Treatment System〕 FIG. 1 is a schematic explanatory view showing the structure of a sewage treatment system in an embodiment of the present invention. As shown in FIG. 1, the sewage treatment system 1 according to the present embodiment includes a sewage treatment unit 10 that receives and treats sewage, an inflow water volume prediction means 20, an SS outflow suppression means 30, and a display means 40. In FIG. 1, the solid arrows indicate that each treatment facility is connected by piping or the like so that water can flow through. The dashed-dotted arrows indicate that they are connected so that control or input / output of information (data) is possible.

[0019] (Sewage Treatment Unit) The sewage treatment unit 10 in the sewage treatment system 1 of this embodiment receives and treats sewage W. More specifically, it may be any facility or equipment that can perform a treatment (sewage treatment step) to obtain treated water W1 with a water quality that can be discharged into a river after receiving sewage W. Examples include what are commonly called sewage treatment plants and final treatment plants. Regarding the sewage treatment unit 10, it may be newly established, or an existing sewage treatment plant or final treatment plant may be used. As an example of the sewage treatment unit 10, as shown in FIG. 1, it may include a grit chamber 11, a primary sedimentation tank 12, a reaction tank 13, and a final sedimentation tank 14, and is capable of treating sewage W to treated water W1. Although not shown in FIG. 1, other known facilities or equipment may be provided for sewage treatment. Such facilities or equipment may include, for example, disinfection equipment provided downstream of the final sedimentation tank 14, as well as facilities or equipment related to sludge treatment discharged from the primary sedimentation tank 12 and the final sedimentation tank 14. On the other hand, the sewage treatment unit 10 in this embodiment is not limited to having all the facilities or equipment shown in FIG. 1. For example, in the case of a small-scale sewage treatment plant where the load of the treatment target (sewage W) is small, or depending on the type and treatment performance of the reaction tank 13, the equipment corresponding to the primary sedimentation tank 12 may be omitted.

[0020] The sewage W flowing into the sewage treatment plant 10 first undergoes sedimentation separation of relatively large-sized solids (such as sand) in the sewage W in the grit chamber 11, and the removal of scum is performed by dust removal equipment 11a such as a screen or scum raiser. Then, the sewage stored on the downstream side (pump well 11b) of the grit chamber 11 is transferred to the primary sedimentation tank 12 via a lift pump P. In the primary sedimentation tank 12, sedimentation separation of heavy suspended solids (sludge) is performed. After organic matter decomposition by biological treatment in the reaction tank 13, sedimentation separation of the suspended substances (SS: microbial flocs, sludge, etc.) generated in the reaction tank 13 is carried out in the final sedimentation tank 14, and then it is discharged outside the system as treated water W1.

[0021] Furthermore, in this embodiment, it is preferable that the sewage treatment unit 10 is equipped with aeration equipment (aeration pipe 31 and blower 32) for aerobic treatment of the reaction tank 13. It is also preferable to provide coagulant addition equipment (chemical (coagulant) storage unit 33 and valve 34) for adding chemicals (coagulants) to the sewage W (water to be treated) introduced into the final sedimentation tank 14. These facilities are used as part of the SS outflow suppression means 30, which will be described later.

[0022] (Means for predicting the amount of water flowing in) In this embodiment, the inflow volume prediction means 20 is for performing an inflow volume prediction step to predict the amount of sewage W flowing into the sewage treatment unit 10. Furthermore, the inflow volume prediction means 20 in this embodiment is not particularly limited as long as it is capable of predicting the amount of sewage W flowing into the sewage treatment unit 10. One example of the inflow volume prediction means 20 in this embodiment is to collect data related to the operating status of the entire sewage treatment unit 10, particularly the sedimentation basin 11 (pump well 11b) (referred to as "facility data") and weather data (referred to as "weather data"), and to predict the sewage inflow using a machine learning model. Specifically, in this case, the facility data collection unit collects data related to the water level of each tank in the sewage treatment unit 10 (pump well 11b, primary sedimentation basin 12, reaction tank 13, final sedimentation basin 14, etc.) and the operating status of the pumps, while the weather data collection unit (corresponding to the weather data acquisition unit 21 described later) collects weather data such as precipitation. Based on this data, a trained model is created using a recurrent neural network (RNN) or its advanced form, LSTM, to predict the amount of sewage W flowing into the sewage treatment unit 10 (future inflow volume).

[0023] Here, from the perspective of activating the SS outflow suppression means 30, which will be described later, at the appropriate timing, it is desirable to predict fluctuations in the amount of sewage W flowing into the sewage treatment unit 10 in a short time and with high accuracy. More specifically, the inflow volume prediction means 20 of this embodiment preferably predicts the inflow volume to the sewage treatment unit 10 within one hour. This makes it possible to accurately grasp the trend of load fluctuations to the sewage treatment unit 10 within a short period of time and to secure the time required to respond to load fluctuations. In particular, even in the case of rapid load fluctuations caused by localized, concentrated rainfall, it becomes easier to proceed without delay in taking measures to suppress the deterioration of treated water quality.

[0024] Furthermore, in the inflow volume prediction means 20 of this embodiment, considering the information accuracy of the various parameters used to predict the inflow volume (in particular, the information accuracy of weather-related data such as that acquired by the weather data acquisition unit 21 described later), it is preferable to predict the inflow volume within one hour ahead, but it is not limited to this. For example, as the information accuracy of the above parameters improves, the inflow volume prediction means 20 may predict the inflow volume further in the future, specifically the inflow volume three hours ahead, and more preferably the inflow volume six hours ahead. Furthermore, from the perspective of ensuring sufficient time to respond to load fluctuations in the sewage treatment system 1, the inflow volume prediction means 20 should predict the inflow volume at least 5 minutes in advance, and preferably 10 minutes in advance. If the inflow volume is predicted for a shorter time, the SS outflow suppression effect of the SS outflow suppression means 30, which reflects the prediction results, may not be fully realized.

[0025] Therefore, the inflow volume prediction means 20 of this embodiment preferably consists of a configuration and calculation content that can predict fluctuations in the inflow volume of sewage W flowing into the sewage treatment unit 10 in a short time and with high accuracy. Specifically, it is possible to predict the inflow volume using information about the pump well 11b, which corresponds to the water tank located on the upstream side of the sewage treatment unit 10. Furthermore, a particularly preferred example of the inflow volume prediction means 20 of this embodiment is one that performs inflow volume prediction including a calculation to obtain an actual value of the inflow volume using the discharge rate of the pump well 11b and the volume of the contents (sewage W) in the pump well 11b.

[0026] As a specific example of the inflow water volume prediction means 20 in this embodiment, as shown in Figure 1, it includes a weather data acquisition unit 21, a water level information acquisition unit 22, a discharge volume information acquisition unit 23, and a contents volume calculation unit 24 for acquiring various information regarding the pump well 11b in the sewage processing unit 10, and further includes an inflow water volume actual value calculation unit 25 for calculating the actual amount of water flowing into the sewage processing unit 10, and an inflow water volume prediction unit 26 for predicting the amount of water flowing into the sewage processing unit 10. The following describes the various components of the inflow water volume prediction means 20 of this embodiment.

[0027] The weather data acquisition unit 21 is for performing a weather data acquisition step to acquire weather-related data (weather data). The weather data acquired by the weather data acquisition unit 21 includes precipitation data based on rainfall forecasts and actual rainfall, as well as wind direction, temperature, and other data. Furthermore, the weather data acquisition unit 21 acquires weather data in the area where rainwater inflow into the sewage treatment system 1 (sewage treatment unit 10) is predicted, based on the location of the sewage treatment system 1. Furthermore, when acquiring data by the weather data acquisition unit 21, it may be done as one of the tasks related to the operation of the sewage treatment system 1, or the data may be provided by a person who collects and manages weather data (such as the Japan Meteorological Agency or a private weather company).

[0028] The water level information acquisition unit 22 is for performing a water level information acquisition step to acquire information regarding the water level of the pump well 11b. The water level information acquisition unit 22 can be any unit that can acquire information regarding the water level of the pump well 11b, which is the water tank located at the furthest upstream of the sewage treatment unit 10. As shown in Figure 1, an example is a unit that acquires information related to the measurement results of the water level gauge S installed in the pump well 11b.

[0029] The discharge volume information acquisition unit 23 is for performing a discharge volume information acquisition step to acquire information regarding the discharge volume of the pump well 11b. The discharge volume information acquisition unit 23 only needs to be capable of acquiring information related to the discharge volume of the pump well 11b, in other words, the amount of water sent from the pump well 11b to the downstream facility (primary sedimentation tank 12 in Figure 1). As shown in Figure 1, an example is one that acquires information related to the discharge volume of the water pump P (such as the flow rate setting value of the water pump P or the measured value of the flow meter).

[0030] The contents volume calculation unit 24 is for performing a contents volume calculation step that calculates the volume of the contents (sewage W) in the pump well 11b. The contents volume calculation unit 24 can be any device capable of performing calculations to obtain information regarding the volume of contents (sewage W) in the pump well 11b. For example, it may include manual calculations, but from the viewpoint of enabling calculations in a short time and with high accuracy, it is preferable to use a computing device that executes the program necessary for this calculation using a processor such as a CPU.

[0031] The inflow volume prediction means 20 of this embodiment performs calculations to obtain information regarding the volume of contents (sewage W) in the pump well 11b, which is the water tank located at the uppermost part of the sewage processing unit 10. Furthermore, the information regarding the volume of contents (sewage W) in the pump well 11b, which is the result of these calculations, is used in the inflow volume actual value calculation unit 25, which will be described later, thereby improving the accuracy of the inflow volume prediction by the inflow volume prediction means 20. Therefore, it is important for the contents volume calculation unit 24 to perform calculations to obtain information about the volume of contents (sewage W) in the pump well 11b with high accuracy. On the other hand, it is undesirable for the acquisition (calculation) of information about the volume of contents in the pump well 11b to become complex or cumbersome. In this embodiment, it is preferable that the contents volume calculation unit 24 performs calculations that take into account the shape of the pump well 11b (shape of the sedimentation basin 11). The pump well 11b often has a slope at part of its bottom so that sewage W, from which sludge and sand have been removed in the sedimentation basin 11, flows in smoothly. In addition, the sedimentation basin 11 may have a recessed bottom rather than being horizontal in order to separate and recover the settled sand. That is, instead of approximating the shape of the pump well 11b as a rectangular parallelepiped, the change in the cross-sectional area of ​​the pump well 11b with respect to its height is taken into consideration, and the relationship between the height of the pump well 11b and the corresponding volume of the pump well 11b is expressed as an equation, and the volume of the contents (sewage W) present in the pump well 11b is calculated using this relationship. More specifically, the relationship between the height and volume of the pump well 11b is derived in advance, and the volume of the contents (sewage W) present in the pump well 11b is calculated using the water level information of the pump well 11b obtained by the water level information acquisition unit 22 described above. As a result, when acquiring information regarding the volume of contents (sewage W) present in the pump well 11b, calculations can be performed using information regarding the water level of the pump well 11b, which is easy to operate, making it possible to acquire information regarding the volume of contents (sewage W) in the pump well 11b with high accuracy and in a simple manner. In addition, when predicting the inflow volume using the inflow volume prediction means 20 of this embodiment, it becomes possible to predict the inflow volume in an even shorter time and with higher prediction accuracy.

[0032] The inflow volume calculation unit 25 is for performing an inflow volume calculation step that calculates the actual value of the amount of water flowing into the sewage processing unit 10. For example, it can calculate the actual value of the inflow volume at a predetermined time (predetermined time) from the results of directly measuring the amount of sewage W flowing into the sedimentation basin 11 (pump well 11b) using a flow meter or the like, or it can calculate the actual value of the inflow volume from information relating to the water level fluctuations in the pump well 11b and the discharge volume of the pump well 11b. In this case, when calculating the actual inflow water volume value from information relating to the water level fluctuation in the pump well 11b and the discharge rate of the pump well 11b, as shown in Figure 1, the actual inflow water volume calculation unit 25 calculates the actual inflow water volume value from information relating to the volume of contents in the pump well 11b obtained by the contents volume calculation unit 24 and information relating to the discharge rate of the pump well 11b obtained by the discharge rate information acquisition unit 23. In the following description, the inflow volume actual value calculation unit 25 will be explained as calculating the inflow volume actual value from the information related to the volume of contents in the pump well 11b obtained by the contents volume calculation unit 24 and the information related to the discharge volume of the pump well 11b obtained by the discharge volume information acquisition unit 23, as shown in Figure 1, but it is not limited to this.

[0033] The inflow volume actual value calculation unit 25 can be any device capable of performing calculations to obtain information related to the actual value of the inflow volume. For example, it may include manual calculations, but from the viewpoint of enabling calculations in a short time and with high accuracy, it is preferable to use a computing device that executes the program necessary for this calculation using a processor such as a CPU.

[0034] The inflow volume prediction unit 26 is for performing an inflow volume prediction step to predict the amount of water flowing into the sewage treatment unit 10. More specifically, it predicts the amount of water that will flow into the sewage treatment unit 10 in the future based on weather data acquired by the weather data acquisition unit 2 and information related to actual inflow volume values ​​acquired by the inflow volume actual value calculation unit 25. The inflow volume prediction unit 26 can be any device capable of performing calculations to obtain information related to the inflow volume prediction, in other words, information related to the expected fluctuations in the inflow volume. For example, it may include manual calculations, but from the viewpoint of enabling calculations in a short time and with high accuracy, it is preferable to use a computing device that executes the program necessary for these calculations using a processor such as a CPU.

[0035] In particular, it is preferable that the inflow volume prediction unit 26 of this embodiment utilizes a learning model created by machine learning training data that associates weather data and actual inflow volume information with the amount of water flowing into the sewage treatment plant. This makes it easier for the inflow volume prediction unit 26 to appropriately handle a large amount of data related to the relationship between weather data and actual inflow volume information and information related to the amount of water flowing into the sewage treatment plant, thereby enabling inflow volume prediction to be performed in a shorter time and with higher prediction accuracy.

[0036] Furthermore, in the inflow volume prediction unit 26 of this embodiment, the time required to acquire information related to the actual inflow volume by the actual inflow volume calculation unit 25 is very short, and the time interval of the inflow volume prediction value is mainly determined according to the time interval of the weather data acquired by the weather data acquisition unit 21 (weather data acquisition span). That is, if the weather data acquisition unit 21 acquires weather data for one hour later (rainfall forecast value, etc.), the inflow volume prediction unit 26 can output the inflow volume prediction value for one hour later (one hour ahead). Alternatively, if the weather data acquisition unit 21 acquires weather data at short time intervals such as 5 minutes or 10 minutes later, the inflow volume prediction unit 26 may perform calculations by accumulating (collecting) the weather data and output the inflow volume prediction value for a desired future (for example, one hour ahead). As mentioned above, the inflow volume prediction unit 26 is not limited to outputting an inflow volume prediction value one hour in advance, but may also output an inflow volume prediction value at a more future point in time. In this case, more time can be obtained for operations (preparation for operations) related to the SS outflow suppression means 30 described later, and it will also be possible to provide advance notification at an earlier stage regarding alarms or work instructions via the display means 40.

[0037] Furthermore, the inflow rate prediction unit 26 of this embodiment outputs an inflow rate prediction value, and if an increase in the inflow rate is predicted, it also outputs information regarding the planned time of the increase in the inflow rate. The determination of "increase in inflow rate" in this case can be based on the inflow rate prediction value exceeding a threshold, or on the fluctuation in the inflow rate prediction value within a predetermined time (the difference from the previous prediction result). The information regarding the planned time of the increase in the inflow rate becomes one of the control parameters related to the operation of the SS outflow suppression means 30, which will be described later.

[0038] In the operation of the inflow volume prediction means 20 of this embodiment, manual operation by workers is possible, but it is preferable to automate a series of operations related to inflow volume prediction by using a computing device (computer) that has data input / output functions for acquiring weather data and information from equipment installed in the sewage processing unit 10 (water level gauge S, water pump P, flow meter, etc.), and executes a program for performing calculations related to acquiring various parameters related to inflow volume prediction using a CPU or other processor. This improves the accuracy of inflow volume prediction, enables quick decision-making, and allows for appropriate understanding of trends regarding the presence or absence of rapid changes in inflow volume.

[0039] Regarding the inflow volume prediction means 20 of this embodiment shown in Figure 1, the information acquired from the constituent facilities and equipment of the sewage treatment unit 10 is information related to one facility (pump well 11b), and furthermore, the equipment involved in acquiring the information (water level meter S, flow meter, etc.) is normally installed in existing sewage treatment plants, and additional installation is easy. In other words, the inflow volume prediction means 20 of this embodiment shown in Figure 1 can perform inflow volume prediction in a short time and with high accuracy, simply and at low cost.

[0040] (Inflow volume prediction process using inflow volume prediction means) Figure 2 shows an example of the process related to inflow volume prediction by the inflow volume prediction means in the sewage treatment system of this embodiment. The following describes each process related to inflow water volume prediction using the inflow water volume prediction means 20 of this embodiment shown in Figure 1, with reference to Figure 2.

[0041] First, as a process for acquiring data related to the pump well 11b in the sewage treatment unit 10, the water level information acquisition unit 22 acquires data related to the water level, and the discharge amount information acquisition unit 23 acquires data related to the discharge amount of the pump well 11b. The water level data is then input to the contents volume calculation unit 24. The contents volume calculation unit 24 considers the change in the cross-sectional area of ​​the pump well 11b with respect to its height and uses a previously derived relationship between the height and volume of the pump well 11b. By inputting the water level data into this relationship, the unit calculates the volume of the contents (sewage W) present in the pump well 11b. The process up to this point related to predicting the amount of inflow water consists entirely of acquiring and calculating information about one facility within the sewage treatment unit 10, specifically the pump well 11b, which is the upstreammost water tank in the sewage treatment unit 10. Since it does not involve acquiring or using other information that could be noise, it is possible to acquire and calculate information quickly (almost in real time) and with high accuracy.

[0042] Next, the data relating to the volume of contents in the pump well 11b, acquired by the contents volume calculation unit 24, and the data relating to the discharge rate of the pump well 11b, acquired by the discharge rate information acquisition unit 23, are input to the inflow water volume actual value calculation unit 25, and the actual value of the inflow water volume to the sewage processing unit 10 is calculated. One example of the calculations performed at this time is that the actual inflow water volume calculation unit 25 uses the discharge rate of the pump well 11b and the volume difference of the contents inside the pump well 11b from the previous calculation to the current calculation (in other words, from after the calculation related to the actual inflow water volume to the sewage treatment unit 10 has been performed until the next calculation) to determine the actual inflow water volume to the sewage treatment unit 10. More specifically, the average value Q of the discharge volume of the pump well 11b acquired by the discharge volume information acquisition unit 23 from the previous calculation to the current calculation, and the volume difference ΔV of the contents in the pump well 11b immediately after the previous calculation and immediately before the current calculation, acquired by the contents volume calculation unit 24, are calculated, and the sum of these (=Q+ΔV) is output as the actual value of the inflow volume of water to the sewage processing unit 10.

[0043] Then, the weather data (data related to precipitation, etc.) acquired by the weather data acquisition unit 21 and the data related to the actual inflow water volume acquired by the inflow water volume actual value calculation unit 25 are input to the inflow water volume forecast unit 26 and output as the inflow water volume forecast value. Information related to the expected time of increase in inflow water volume is also output. One example of how to predict (calculate) the inflow volume in this case is to use weather data and actual inflow volume data as input data, and to perform calculations using a pre-created learning model that has been trained on training data of the inflow volume to the sewage treatment plant at that time as output data.

[0044] Furthermore, the predicted inflow water volume value output from the inflow water volume prediction unit 26 may be output externally, and the means and timing of this output are not particularly limited. For example, it is preferable to output it externally via the display means 40, which will be described later. Furthermore, the information regarding the expected time of increase in the inflow volume output from the inflow volume prediction unit 26 is input to the SS outflow suppression means 30, which will be described later.

[0045] Furthermore, the inflow volume prediction means 20 of this embodiment is not limited to the configuration and calculation contents shown in Figures 1 and 2, but is acceptable as long as it enables inflow volume prediction in a short time and with high accuracy, and makes available information regarding the predicted inflow volume value and the expected time of increase in the inflow volume (enabling input to other configurations and processes within the sewage treatment system 1 or external output).

[0046] (SS outflow control means) The SS outflow suppression means 30 in this embodiment is a means to suppress the deterioration of the water quality of treated water, and more specifically, it is for performing an SS outflow suppression step that reduces the amount of suspended solids (SS) that flows into the treated water. Furthermore, the SS outflow suppression means 30 in this embodiment is activated before the scheduled time of increase in the inflow water volume predicted by the inflow water volume prediction means 20. In this context, "before the scheduled time of increase in inflow volume" means before the timing (time) when the increase in inflow volume in the sewage treatment unit 10 occurs, based on the results predicted by the inflow volume prediction means 20. It is particularly preferable that this be before the timing (time) when the inflow volume exceeds the amount at which SS outflow into treated water W1 is a concern. This makes it possible to take measures against factors that cause a deterioration in the quality of treated water W1 due to an increase in the inflow volume (SS outflow into treated water W1) before the inflow volume of sewage W increases within the sewage treatment unit 10. In other words, it becomes possible to proceed without delay in responding to fluctuations in the inflow volume of sewage W in order to suppress the deterioration of treated water quality. Furthermore, localized, concentrated rainfall may cause the amount of wastewater treated in the sewage treatment system 1 (sewage treatment section 10) to exceed the planned treatment volume. However, even in such cases, the SS outflow suppression means 30 of this embodiment allows for measures to suppress SS outflow before the amount of wastewater W flowing into the sewage treatment section 10 increases. Therefore, the sewage treatment system 1 of this embodiment can continue to accept wastewater in the sewage treatment section 10 without stopping, and then implement measures to suppress the deterioration of treated water quality.

[0047] In this embodiment, the SS outflow suppression means 30 preferably includes the addition of chemicals and / or stopping aeration in the sewage treatment unit 10. More specifically, the SS outflow suppression means 30 may include stopping aeration via the aeration equipment (diffuser 31 and blower 32) related to aerobic treatment in the reaction tank 13, or using a coagulant as a chemical and adding it to the sewage W before the settling and separation of suspended solids (SS) in the final sedimentation tank 14.

[0048] First, I will explain the aeration stop, which is one of the SS outflow suppression means 30. When aerobic treatment is performed as biological treatment for the decomposition of organic matter in the reaction tank 13, aeration is carried out by the diffuser pipe 31 and blower 32. At this time, aerobic microorganisms are activated in the reaction tank 13, and microbial flocs, which are a type of suspended solids (SS), are dispersed throughout the tank. If the amount of sewage W (water to be treated) flowing into the reaction tank 13 increases in this state, a large amount of SS (microbial flocs) present in the upper part of the reaction tank 13 will flow out into the downstream equipment (final sedimentation tank 14), resulting in the outflow of SS into the treated water W1. Therefore, by stopping aeration before the scheduled time when the amount of inflow is expected to increase, based on the results obtained from the inflow volume prediction means 20, the SS (microbial flocs) that were dispersed throughout the reaction tank 13 will settle to the bottom of the reaction tank 13, and the outflow to the downstream equipment will be suppressed.

[0049] Next, we will explain the chemical addition method, which is one of the SS outflow suppression means 30. Based on the results obtained by the inflow volume prediction means 20, a coagulant is added to the sewage W before the final sedimentation tank 14 is used to separate suspended solids (SS) by sedimentation, using a coagulant as a chemical, before the scheduled time when the inflow volume is expected to increase. More specifically, in a chemical addition means consisting of a chemical (coagulant) storage section 33 in which the coagulant is stored, a line L1 connecting the piping that introduces sewage W (water to be treated) from the reaction tank 13 to the final sedimentation tank 14 and the chemical (coagulant) storage section 33, the valve 34 is opened based on the results obtained by the inflow volume prediction means 20 before the scheduled time when the inflow volume is expected to increase, and the coagulant is added to the sewage W before the final sedimentation tank 14 is used to separate suspended solids (SS) by sedimentation. By allowing the SS present in the final sedimentation tank 14 to settle before the inflow volume in the sewage treatment section 10 increases, the outflow of SS to downstream equipment (such as disinfection equipment) or to treated water at discharge is suppressed. Furthermore, as for the chemical addition in the SS outflow suppression means 30, a coagulant may be added to the sewage W before sedimentation separation is performed in the primary sedimentation tank 12. However, from the viewpoint of efficiently exhibiting a high SS sedimentation effect by the coagulant, it is preferable to add the coagulant to at least the sewage W (water to be treated) introduced from the reaction tank 13 to the final sedimentation tank 14.

[0050] The SS outflow suppression means 30 of this embodiment performs operations that have a relatively rapid effect on SS sedimentation, such as adding chemicals or stopping aeration, before the scheduled time when the inflow volume increases. This makes it possible to promote SS sedimentation in the sewage treatment unit 10 or maintain the SS sedimentation state before the inflow volume increases. As a result, even if the inflow volume to the sewage treatment unit 10 increases, it is possible to minimize the outflow of SS to the treated water W1, and consequently, to proceed with measures to suppress the deterioration of treated water quality without delay.

[0051] Furthermore, the SS outflow suppression means 30 can be either chemical addition or aeration cessation, but by performing both chemical addition and aeration cessation, the effect of promoting and maintaining SS sedimentation in the sewage treatment unit 10 can be further enhanced.

[0052] (Display means) The display means 40 in this embodiment is for displaying alarms or work instructions based on information obtained from the inflow water volume prediction means 20. In this embodiment, the display means 40 may, for example, notify workers of alarms or work instructions using strings of characters or symbols via a display device (such as a monitor) capable of displaying numerical values ​​or images when the predicted inflow water volume exceeds a value (threshold) that requires action by workers, as well as providing notifications by sound or light. The display means 40 may also continuously output the predicted inflow water volume to an external source, enabling workers to check (continuously monitor) the information. This allows workers to quickly and accurately respond to events estimated from the predicted inflow water volume (such as decreased treatment efficiency or SS outflow), thereby facilitating smooth maintenance and management of the sewage treatment system and optimizing its continued operation.

[0053] As described above, the sewage treatment system and operating method of the sewage treatment system of this embodiment predict the amount of sewage to be treated (inflow volume) flowing into the sewage treatment unit, which receives and treats the sewage, and implements measures to suppress the outflow of suspended solids into the treated water as a means of suppressing the deterioration of the water quality of the treated water before the time when the inflow volume is expected to increase based on the prediction results. This makes it possible to proceed without delay in responding to fluctuations in the amount of sewage inflow in order to suppress the deterioration of the treated water quality.

[0054] The embodiments described above are merely examples of a sewage treatment system and a method for operating a sewage treatment system. The sewage treatment system and the method for operating a sewage treatment system according to the present invention are not limited to the embodiments described above, and the sewage treatment system and the method for operating a sewage treatment system according to the embodiments described above may be modified without changing the gist of the claims. [Industrial applicability]

[0055] The wastewater treatment system and operating method of the wastewater treatment system of the present invention are suitably utilized in technologies related to wastewater treatment. Furthermore, the wastewater treatment system and operating method of the wastewater treatment system of the present invention are particularly suitable for use in situations where rapid load fluctuations due to localized, concentrated rainfall can be addressed without delay, enabling measures to suppress the deterioration of treated water quality. [Explanation of Symbols]

[0056] 1 Sewage treatment system, 10 Sewage treatment section, 11 Grit basin, 11a Debris removal equipment, 11b Pump well, 12 Primary sedimentation tank, 13 Reaction tank, 14 Final sedimentation tank, 20 Inflow volume prediction means, 21 Weather data acquisition unit, 22 Water level information acquisition unit, 23 Discharge volume information acquisition unit, 24 Content volume calculation unit, 25 Inflow volume actual value calculation unit, 26 Inflow volume prediction unit, 30 SS outflow suppression means, 31 Aeration pipe, 32 Blower, 33 Chemical (coagulant) storage unit, 34 Valve, 40 Display means, L1 Line, P Water pump, S Water level meter, W Sewage, W1 Treated water

Claims

1. A sewage treatment unit that receives and treats sewage, Inflow volume prediction means for predicting the amount of water flowing into the sewage treatment unit, A sewage treatment system characterized by comprising SS outflow suppression means for reducing the amount of suspended solids outflow into the treated water before the scheduled time of increase in the inflow volume predicted by the inflow volume prediction means.

2. The wastewater treatment system according to claim 1, characterized in that the inflow volume prediction means predicts the amount of wastewater flowing into the wastewater treatment unit within one hour ahead.

3. The wastewater treatment system according to claim 1, characterized in that the inflow volume prediction means predicts the amount of wastewater flowing into the wastewater treatment unit based on actual values ​​of the amount of wastewater flowing into the wastewater treatment unit and weather data.

4. The wastewater treatment system according to claim 1, characterized in that the means for suppressing SS outflow includes adding chemicals and / or stopping aeration in the wastewater treatment unit.

5. The sewage treatment system according to claim 1, further comprising a display means for displaying an alarm or work instruction based on information obtained by the inflow water volume prediction means.

6. A method for operating a sewage treatment system equipped with a sewage treatment section for receiving and treating sewage, A sewage treatment step in the sewage treatment unit, which involves receiving and treating sewage, The inflow volume prediction step predicts the amount of water flowing into the aforementioned sewage treatment unit, A method for operating a sewage treatment system, comprising: an SS outflow suppression step that reduces the amount of suspended solids outflow into the treated water before the scheduled time of increase in the inflow predicted in the inflow prediction step.

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