Pollutant load monitoring system and method for grasping pollutant load

Abstract

To provide a pollution load monitoring system which can automatically acquire and monitor a BOD conversion value (pollution load information) of inflow water flowing into an aeration tank.SOLUTION: A pollution load remote monitoring system 1, which acquires pollution load information in a wastewater treatment facility 2 provided with an aeration tank 25, includes: a turbidity meter which measures the turbidity of aeration tank inflow water, which is inflow water flowing into the aeration tank 25; an electric conductivity meter which measures the electric conductivity of the aeration tank inflow water; and an arithmetic device 11 which calculates a BOD conversion value on the basis of measured values of the turbidity meter and the electric conductivity meter. When the BOD conversion value exceeds a predetermined value, the monitoring system outputs alarm information (transmits it to an information processing device 4).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a pollution load monitoring system for acquiring pollution load information in a wastewater treatment facility equipped with an aeration tank of the activated sludge method and a method for grasping the pollution load.

Background Art

[0002] In various treatment facilities and the like, monitoring of their operating conditions and the like is performed. As a technology related to this, Patent Document 1 discloses a technology related to an operation management device for a water treatment plant that manages the operation of the water treatment plant based on at least two or more items of data indicating the operating state of the water treatment plant.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As one of the information for making the operating conditions in the wastewater treatment facility appropriate, pollution load information indicating fluctuations in the water quality of the treated water can be mentioned. By grasping the degree of the pollution load (amount of organic matter), more appropriate operating conditions can be determined. In a wastewater treatment facility equipped with an aeration tank, the BOD (Biochemical Oxygen Demand) of the influent water flowing into the aeration tank is used as pollution load information. However, the measurement of BOD is for a certain period (BOD 5If so, the sample water is temperature-controlled in a thermostat for 5 days, the amount of oxygen before and after that is measured, and the amount of consumed oxygen is calculated. Conventionally, since the sample water is obtained and measured at an analysis institution, it is difficult to measure in real time. For example, it was difficult to capture and analyze fluctuations over time.

[0005] In view of the above points, an object of the present invention is to provide a pollution load monitoring system capable of automatically acquiring the BOD conversion value (pollution load information) of the influent water flowing into the aeration tank and monitoring this.

Means for Solving the Problems

[0006] (Configuration 1) A monitoring system for acquiring pollution load information in a wastewater treatment facility equipped with an aeration tank, a turbidimeter for measuring the turbidity of the influent water to the aeration tank, which is the influent water to the aeration tank, a conductivity meter for measuring the conductivity of the influent water to the aeration tank, and an arithmetic unit for calculating a BOD conversion value based on the measured values of the turbidimeter and the conductivity meter. A pollution load monitoring system.

[0007] (Configuration 2) The pollution load monitoring system according to Configuration 1, which outputs warning information when the BOD conversion value exceeds a predetermined value.

[0008] (Configuration 3) First correlation information, which is correlation information between the measured values of the turbidimeter and the conductivity meter and COD, and second correlation information, which is correlation information between COD and BOD, are each preset, and based on the measured values of the turbidimeter and the conductivity meter, a COD conversion value is calculated using the first correlation information, and based on the COD conversion value, the BOD conversion value is calculated using the second correlation information. The pollution load monitoring system according to Configuration 1 or 2.

[0009] (Configuration 4) The first correlation information is a multiple regression equation, having a first multiple regression equation and a second multiple regression equation. When the COD conversion value calculated using the first multiple regression equation based on the measured values of the turbidimeter and the conductivity meter is equal to or greater than a threshold value, the COD conversion value is recalculated using the second multiple regression equation based on the measured values of the turbidimeter and the conductivity meter. The pollution load monitoring system according to Configuration 3.

[0010] (Configuration 5) When the measured value of the turbidimeter exceeds a predetermined value, or when the measured value of the turbidimeter changes by a predetermined value or more within a predetermined time, the measured value is not used. The pollution load monitoring system according to any one of Configurations 1 to 4.

[0011] (Configuration 6) An Rr automatic measurement device for automatically measuring the oxygen utilization rate (Rr) of the mixed liquid in the aeration tank, comprising a sampling tank, an inflow means for flowing the mixed liquid in the aeration tank into the sampling tank, an aeration means provided in the sampling tank, and a dissolved oxygen concentration meter provided in the sampling tank. The mixed liquid collected in the sampling tank is aerated by the aeration means, then the aeration is stopped, the DO value is measured by the dissolved oxygen concentration meter, and an Rr automatic measurement device for measuring the oxygen utilization rate (Rr) based on the measured DO value is provided. The pollution load monitoring system according to any one of Configurations 1 to 5.

[0012] (Configuration 7) An SV automatic measurement device for automatically measuring the activated sludge sedimentation rate (SV) of the mixed liquid in the aeration tank, comprising a sampling tank made of a transparent container, an inflow means for flowing the mixed liquid in the aeration tank into the sampling tank, and a camera for photographing the sampling tank. After the mixed liquid collected in the sampling tank is allowed to stand for a predetermined time, an SV automatic measurement device for photographing the sampling tank containing the mixed liquid that has been allowed to stand by the camera is provided. The pollution load monitoring system according to any one of Configurations 1 to 6.

[0013] (Configuration 8) A method for grasping the pollution load in the monitoring of a wastewater treatment facility equipped with an aeration tank, comprising the steps of: obtaining in advance the correlation information between the turbidity information and conductivity information of the influent water to the aeration tank, which is the influent water to the aeration tank, and the BOD of the influent water to the aeration tank; obtaining the turbidity information and conductivity information of the influent water to the aeration tank at any time, and calculating a BOD conversion value based on the obtained turbidity information and conductivity information and the correlation information. A method for grasping the pollution load.

Effect of the Invention

[0014] According to the pollution load monitoring system of the present invention, it is possible to automatically obtain the BOD conversion value (pollution load information) of the influent water flowing into the aeration tank and monitor it.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. Note that the following embodiments are one form when embodying the present invention and do not limit the present invention within its scope.

[0017] <Embodiment 1> FIG. 1 is a block diagram showing an outline of the configuration of a pollution load remote monitoring system (pollution load monitoring system) according to Embodiment 1 of the present invention. The pollution load remote monitoring system 1 of the present embodiment is a remote monitoring system for acquiring pollution load information in a wastewater treatment facility 2 equipped with an aeration tank 25. It records (logs) the BOD conversion value, which is the pollution load information automatically acquired, and when the BOD conversion value exceeds a predetermined value, it transmits warning information to an information processing device 4 via a network 3 (outputs warning information). The BOD conversion value (mg / L) is an assumed value (estimated value) of BOD calculated by this system by the method described below. Similarly, the COD Cr conversion value (mg / L) is the assumed value (estimated value) of COD Cr calculated by this system.

[0018] The wastewater treatment facility 2 to be monitored is, for example, a water treatment facility for treating wastewater in a food factory or the like, a raw water pump tank 21 for flowing in raw water (factory wastewater to be treated), a flow adjustment tank 22 for adjusting the flow rate, a pretreatment device 23 such as pressure - normal pressure flotation or coagulation sedimentation, an aeration tank 25 for performing biological treatment by the activated sludge method, a sedimentation tank or membrane separation tank 26 for performing solid - liquid separation, a disinfection tank 27 for performing disinfection treatment, a discharge pump tank 28 for discharging, It includes the following. Note that the wastewater treatment facility itself and the content of the water treatment in the wastewater treatment facility are not the direct objects of the present invention. Since any conventional wastewater treatment facility (wastewater treatment facility equipped with an aeration tank) can be used (the configuration as a wastewater treatment facility is not limited to the configuration shown in FIG. 1), the description here regarding the wastewater treatment facility itself and the treatment content in the wastewater treatment facility is omitted.

[0019] The pollution load remote monitoring system 1 of this embodiment is a remote monitoring system capable of automatically measuring (monitoring) the pollution load information (BOD conversion value) of the influent water flowing into the aeration tank 25 almost in real time, that is, monitoring the load state of the aeration tank 25. The pollution load remote monitoring system 1 of this embodiment includes an influent water monitoring tank 12 for the aeration tank provided on the inflow path 24 of the influent water to the aeration tank 25, and a remote monitoring device 11 that performs calculation processing of the BOD conversion value, which is pollution load information, based on the sensor values of the sensors provided in the influent water monitoring tank 12 for the aeration tank.

[0020] FIG. 2 is a diagram showing an outline of the configuration of the influent water monitoring tank 12 for the aeration tank. The influent water monitoring tank 12 for the aeration tank of this embodiment is provided on the inflow path 24 of the influent water to the aeration tank, and includes an influent water monitoring tank 121 where the influent water flowing into the aeration tank 25 is collected, a turbidimeter 122 installed in the influent water monitoring tank 121 for measuring the turbidity of the influent water to the aeration tank, and a conductivity meter 123 installed in the influent water monitoring tank 121 for measuring the conductivity of the influent water to the aeration tank. It is equipped with the above. The turbidimeter 122 has a light emitting part and a light receiving part (not particularly shown), and is a sensor that irradiates light to the influent water to the aeration tank in the influent water monitoring tank 121 and detects the transmitted light (or there is also a scattered light type, etc.). It is used as a sensor for detecting turbidity, that is, information regarding the turbidity of water due to dirt not dissolved in water. Note that any sensor capable of measuring turbidity can be used as the turbidimeter. The conductivity meter 123 is a sensor that measures the conductivity of the influent water in the influent water monitoring tank 121 of the aeration tank, and is used as a sensor for detecting dirt dissolved in water (when there is more dirt dissolved (ionized) in water, the conductivity increases).

[0021] As shown in FIG. 1, the remote monitoring device 11 has an input / output terminal 112 to which the influent water monitoring tank 12 of the aeration tank is connected, and a storage unit 113 that stores information such as information regarding "correlation information between the turbidity information and conductivity information of the influent water in the aeration tank, the BOD of the influent water in the aeration tank" to be described below, an input / output unit 114 that is an input interface for the user (any input means such as an operation button, keyboard, touch panel, or voice input unit) and an output interface (any output means such as a visual display device such as a display screen or indicator, or an auditory output unit such as a speaker), a transmission / reception unit 115 that transmits and receives information to and from the information processing device 4 via the network 3, and a control / arithmetic unit 111 that performs control, arithmetic processing, etc. of the device, and has a function as an "arithmetic device that calculates a BOD conversion value based on the measured values of the turbidity meter and the conductivity meter" as will be described later. Note that the input / output terminal 112 is connected to the control / arithmetic unit 111 via an appropriate signal for input / output to the control / arithmetic unit 111, and via an amplification circuit, A / D conversion circuit, filter circuit, etc. (not shown) as appropriate. The remote monitoring device 11 can be configured by any information processing device such as a microcomputer such as a PLC or MCU, or a PC that can execute the processes to be described below.

[0022] Note that the network 3 may be any network such as the Internet or a local area network, and may be either wired or wireless (the transmission / reception unit 115 appropriately uses one suitable for the type of network, etc.). Also, the information processing device 4 is any device such as a PC or a mobile terminal owned by, for example, the administrator of the wastewater treatment facility 2.

[0023] In order for the remote monitoring device 11 to automatically measure (monitor) the pollution load information (BOD conversion value) of the influent water of the aeration tank almost in real time, the "correlation information between the turbidity information and conductivity information of the influent water of the aeration tank and the BOD of the influent water of the aeration tank" has been acquired and set in advance. In the present embodiment, the "correlation information between the turbidity information and conductivity information of the influent water of the aeration tank and the BOD of the influent water of the aeration tank" is 1. The first correlation information, which is the correlation information between the measured values of the turbidimeter and the conductivity meter and COD Cr and 2. The second correlation information, which is the correlation information between COD Cr and BOD It is composed of two-stage correlation information. The first correlation information is composed of a first multiple regression equation and a second multiple regression equation.

[0024] The first correlation information is the correlation information between the measured values of the turbidimeter and the conductivity meter and COD (Chemical Oxygen Demand, chemical oxygen demand, unit: mg / L), and is obtained and set by sampling in advance the influent water of the aeration tank flowing into the aeration tank 25. More specifically, the influent water of the aeration tank is sampled periodically and repeatedly, and the turbidity and conductivity of each of the collected samples and COD Cr are actually measured, and multiple regression analysis is performed with turbidity and conductivity as explanatory variables and COD Cr as the objective variable to calculate the correlation information (multiple regression equation). As an example (experiment), sampling was performed every 6 hours at a certain site, a considerable number of sample data were obtained, and multiple regression analysis was performed based on these sample data. In this experiment, the actual measured value of COD Cr and the converted value of COD Cr calculated based on the multiple regression equation calculated from turbidity and conductivity had an error of about -25% to +15%, and the positive and negative of the error reversed (the trend changed) with a predetermined value of the converted value of COD Cr as the boundary. Therefore, dividing at the point (predetermined value) where the positive and negative of the error reverse as the boundary, the respective multiple regression equations (CODCr Obtained a first multiple regression equation used when it is less than a predetermined value and a second multiple regression equation used when it is greater than or equal to the predetermined value), and performed a case-by-case analysis to calculate the COD Cr converted value. As a result, the error between the actual measured value of COD Cr and the converted value of COD Cr could be kept within a range of approximately ±10%. Such a tendency is based on the phenomenon that when an electrolyte is dissolved in pure water, the relationship between concentration and conductivity is proportional when it is low, but the gradient becomes smaller as the concentration increases, and when measuring the conductivity while dissolving an electrolyte in an aqueous solution of an organic compound, the gradient is large when the concentration of the organic compound is low, and the gradient becomes smaller when the concentration of the organic compound is high (based on these phenomena, as the converted value of COD Cr increases, the tendency changes). Therefore, it is considered that the error can be reduced by using a multiple regression equation that is case-by-case (including those divided into two or more cases and those not case-by-case) as necessary based on sampling at each site.

[0025] In sampling, when the turbidity value exceeded a predetermined value (specifically, 600 NTU in the above embodiment), the multiple regression analysis was performed without using the data. Since the turbidimeter is a sensor that irradiates light to a sample and detects the transmitted light as described above, when a solid crosses and blocks the light immediately before the light-emitting sensor or the light-receiving sensor, the turbidity (sensor value) may increase as spike-like noise data. Such spike-like noise data does not correctly reflect the turbidity, so it is excluded from the processing. Here, an example is given in which this is excluded when the turbidity (sensor value) exceeds (or becomes greater than or equal to) a predetermined value. However, when the turbidity (sensor value) changes by more than a predetermined value within a predetermined time (when it spikes rapidly up or down), this may also be excluded.

[0026] The second correlation information is COD in the above sampling CrMeasure the BOD of the samples (one or several points are acceptable), and obtain them as these ratios (conversion formulas).

[0027] The first correlation information and the second correlation information (parameters of each conversion formula) obtained as above are input (set) by the user using the input / output unit 114 and stored in the storage unit 113. Also, the COD Cr value (predetermined value) used for the case distinction between the first multiple regression formula and the second multiple regression formula is also set and stored as a threshold value.

[0028] Next, the outline of the processing operation of the remote monitoring device 11 will be described with reference to the flowchart of FIG. 3. In the following description, the processing subject is omitted, but each process is executed by the control / operation unit 111 by using information obtained from the storage unit 113 or the input / output terminal 112. At a predetermined measurement timing (the measurement timing may be arbitrarily set, such as a preset measurement time or measurement at a preset time interval), the sensor values of the turbidimeter 122 and the conductivity meter 123 are read to obtain the turbidity and conductivity of the influent water of the aeration tank (step 301). At this time, if the turbidity exceeds a predetermined value, the turbidity measurement is repeated (step 302). Similar to the sampling described above, it is intended to exclude spike-like noise data ("if the measured value of the turbidimeter exceeds a predetermined value, or if the measured value of the turbidimeter changes by a predetermined value or more within a predetermined time, the measured value is not used"). Note that when repeating the turbidity measurement, the conductivity may be re-measured, or the conductivity may not be re-measured.

[0029] After obtaining the turbidity and conductivity of the influent water of the aeration tank, calculate the COD conversion value using the first multiple regression formula (first correlation information) from these (step 303). If the COD conversion value is equal to or greater than the threshold value, recalculate the COD conversion value using the second multiple regression formula (first correlation information) (step 304: Yes → step 305). In the subsequent step 306, the COD conversion value calculated by the first multiple regression equation (step 303) or the second multiple regression equation (step 305) is converted into a BOD conversion value (the BOD conversion value is calculated using the second correlation information), and this is logged (stored in the storage unit 113).

[0030] When the calculated BOD conversion value is equal to or greater than a predetermined value (a value preset according to the equipment conditions and operating conditions of each site, etc.), an alert (warning information) is transmitted to the information processing device 4 via the network 3 (step 307: Yes → step 308).

[0031] In the subsequent step 309, it waits for the arrival of the next measurement timing (as described above, the measurement timing can be arbitrarily set, such as a preset measurement time or measurement at a preset time interval), and when the next measurement timing arrives, it returns to step 301 and repeats the above process. By the above process, the turbidity information and conductivity information of the influent water of the aeration tank are acquired at any time, and the BOD conversion value is calculated and stored based on these and the correlation information. Therefore, the BOD conversion value (pollution load information) of the influent water flowing into the aeration tank can be automatically acquired (and logged) almost in real time.

[0032] As described above, according to the pollution load remote monitoring system 1 of the present embodiment, the BOD conversion value (pollution load information) of the influent water flowing into the aeration tank can be automatically acquired (and logged) almost in real time, and it can be remotely monitored. Conventionally, the measurement of BOD was carried out over a certain period (BOD 5If so, the amount of oxygen consumed by temperature-controlling the sample water in a thermostat for 5 days was measured. Therefore, it was basically measured by an analytical institution, and it was difficult to measure in real time on-site. For example, it was difficult to capture fluctuations over time. However, according to the pollution load remote monitoring system 1 of the present embodiment, these become possible. By enabling real-time measurement, even when the load changes rapidly, it becomes possible to immediately respond to this (such as optimizing operating conditions), which is very useful. In addition, since the load situation can be continuously logged, by analyzing the data, it becomes possible to grasp trends (such as seasonal trends) and take preventive measures in advance according to changes in the load situation based on the trends.

[0033] In the present embodiment, only the point of receiving an alert when the BOD conversion value of the information processing device 4 becomes a predetermined value or more (that is, when the load increases) is described. However, it is of course possible to access the BOD conversion value logged from the information processing device 4 to the remote monitoring device 11 and refer to the real-time BOD conversion value.

[0034] In the present embodiment, the "correlation information between the turbidity information and conductivity information of the aeration tank influent water and the BOD of the aeration tank influent water" is the "1. The first correlation information that is the correlation information between the measured values of the turbidimeter and the conductivity meter and COD Cr and the second correlation information that is the correlation information between 2. COD Cr and BOD" is taken as an example of being composed of two-stage correlation information. However, the present invention is not limited to this. For example, in sampling, the turbidity and conductivity of each sample and the BOD are actually measured, and multiple regression analysis is performed with turbidity and conductivity as explanatory variables and BOD as the target variable, so that the BOD conversion value can be directly calculated from turbidity and conductivity. However, it is necessary to actually measure the BOD for a plurality of samples during sampling, and BOD 5If so, it is necessary to control the temperature of the sample in a thermostat for 5 days, which makes it very time-consuming to obtain correlation information (a considerable number of samplings). On the other hand, according to the two-stage method of the embodiment, the measurement of BOD can be completed with one or several samples, so the operation of obtaining correlation information is made more efficient. The "correlation information between the turbidity information and conductivity information of the influent water of the aeration tank and the BOD of the influent water of the aeration tank" may be updated as necessary. For example, in the case where the production situation in the factory has changed, etc., the correlation information may be updated based on sampling for the changed wastewater (influent water of the aeration tank). Also, periodically, the actual measurement of the BOD of the influent water of the aeration tank may be performed, the error from the BOD conversion value may be confirmed, and if the error seems large, the correlation information may be updated (sampled).

[0035] In this embodiment, as an example, COD Cr is used, but the present invention is not limited to this. For example, as COD, COD Mn or the like may be used. Also, in the embodiment, an example is given of logging the BOD conversion value, but of course, the COD conversion value may also be logged.

[0036] In this embodiment, as an example, when the BOD conversion value (pollution load information) is equal to or greater than a predetermined value, an alert (warning information) is transmitted to the information processing device 4 (the warning information is output). However, not only a simple alert but also an instruction to change the recommended operating conditions (for example, something that specifically indicates the operation amount of the valve to reduce the inflow amount so that the load of the aeration tank does not become too high) may be notified. Also, the output of the warning information is not limited to being transmitted to the information processing device 4. For example, it may be something that outputs a warning in a device installed in the wastewater treatment facility 2.

[0037] <Embodiment 2> FIG. 4 is a block diagram showing an outline of the configuration of the pollution load remote monitoring system according to Embodiment 2. For components having the same configuration as those in Embodiment 1, the same reference numerals as those in Embodiment 1 (FIG. 1) are used, and the description here is simplified or omitted.

[0038] The pollution load remote monitoring system 1' of this embodiment has the same configuration and functions as the pollution load remote monitoring system 1 of Embodiment 1, and further includes an Rr, SV automatic measurement device 13, so as to automatically measure the oxygen utilization rate (Rr) and the activated sludge sedimentation rate (SV) of the aeration tank mixed liquor (hereinafter simply referred to as "mixed liquor"), which is a mixed liquid of activated sludge and raw water in the aeration tank 25.

[0039] FIG. 5 is a block diagram showing an outline of the configuration of the Rr, SV automatic measurement device 13. The Rr, SV automatic measurement device 13 includes a sampling tank 131 made of a transparent container, inflow means 132 for flowing the mixed liquor in the aeration tank 25 into the sampling tank 131, aeration means (aeration nozzle 1331 and blower 1332) provided in the sampling tank 131 for supplying oxygen to the mixed liquor in the sampling tank 131, a dissolved oxygen concentration meter 134 provided in the sampling tank 131 for measuring the dissolved oxygen concentration of the mixed liquor in the sampling tank 131, a camera 135 for photographing the sampling tank 131, a water level meter 136 for measuring the water level in the sampling tank 131, a circulation path 137 for circulating the water in the sampling tank 131, cleaning means 138 for flowing cleaning water into the sampling tank 131, a discharge path 139 for discharging the water in the sampling tank 131, and is provided with.

[0040] The inflow means 132 has an upstream sampling path 1321 for collecting the mixed liquor from the inflow side of the aeration tank 25, a downstream sampling path 1322 for collecting the mixed liquor from the outflow side of the aeration tank 25, and a pump 1323. In addition, each path is provided with an electric valve (denoted as MV in the figure) for opening and closing each path. Each electric valve, pump 1323, blower 1332, and camera 135 are connected to be controllable by the control and arithmetic unit 111 of the remote monitoring device 11. Also, the measured values of the water level gauge 136 and the dissolved oxygen concentration meter 134 are connected so as to be acquirable by the control and arithmetic unit 111.

[0041] Next, the outline of the process for automatically measuring the oxygen utilization rate (Rr) and the activated sludge sedimentation rate (SV) of the mixed liquid in the aeration tank 25 will be described with reference to the flowcharts in FIGS. 6 to 8. In the following description, the processing subject is omitted, but each process is executed by the control and arithmetic unit 111 in the same manner as in Embodiment 1.

[0042] FIG. 6 is a flowchart showing the overall outline of the automatic measurement process of Rr and SV. The loop processes of Step 601 and Step 602 are processes for waiting for the arrival of the measurement timings of Rr and SV respectively. Each measurement timing may be arbitrarily set, such as a preset measurement time or measurement at a preset time interval. When the measurement timing of Rr arrives (Step 601: Yes), it proceeds to Step 603 to perform the Rr measurement process (described below), records (logs) the obtained Rr data, and transmits it to the information processing device 4 via the network 3 (Step 604). When the measurement timing of SV arrives (Step 602: Yes), it proceeds to Step 605 to perform the SV measurement process (described below), records (logs) the obtained SV data, and transmits it to the information processing device 4 via the network 3 (Step 606).

[0043] FIG. 7 is a flowchart showing the outline of the processing operation of the automatic measurement of Rr executed in Step 603 of FIG. 6. First, a predetermined amount of the mixed liquor from the aeration tank 25 is allowed to flow into the sampling tank 131 (step 701). This process is carried out by opening either the electric valve on the upstream sampling path 1321 (any other mechanism can be substituted as long as it can switch the route, such as a solenoid valve) or the electric valve on the downstream sampling path 1322, while closing the electric valves of the circulation path 137 and the discharge path 139, and driving the pump 1323 until the water level obtained by the water level gauge 136 reaches a predetermined value. Note that the reason for enabling the sampling of the mixed liquor from both the inflow side and the outflow side of the aeration tank 25 is to evaluate the raw water load by measuring Rr on the inflow side (upstream side) and to detect the treatment failure of the biological treatment by measuring Rr on the outflow side (downstream side), respectively. That is, depending on each purpose, a process of opening either the electric valve on the upstream sampling path 1321 or the electric valve on the downstream sampling path 1322 is carried out. When a predetermined amount of the mixed liquor has been sampled, the blower 1332 is driven to aerate the mixed liquor, and the aeration is continued until the measured value (DO value) by the dissolved oxygen concentration meter 134 reaches a predetermined value 1 (for example, 5 mg / L) (that is, the mixed liquor in the sampling tank 131 is brought to a predetermined dissolved oxygen concentration). When it reaches the predetermined value 1, the blower 1332 is stopped to stop the aeration (steps 702 to 704). After the mixed liquor in the sampling tank 131 has been brought to a predetermined dissolved oxygen concentration, the dissolved oxygen concentration of the mixed liquor in the sampling tank 131 is measured at predetermined intervals while stirring the mixed liquor. When the dissolved oxygen concentration becomes equal to or lower than a predetermined value 2 (for example, 1 mg / L), Rr is calculated based on the time taken for the dissolved oxygen concentration to change from the predetermined value 1 to 2 and the values of the predetermined values 1 and 2 (steps 705 to 707). Note that "stirring the mixed liquor" is carried out by closing the electric valves of the upstream sampling path 1321, the downstream sampling path 1322, and the discharge path 139, opening the electric valve of the circulation path 137, and driving the pump 1323. When the measurement of Rr is completed, the drainage and cleaning process of the sampling tank 131 (step 708) is performed to end the Rr measurement process. The drainage of the sampling tank 131 is performed by opening the electric valve in the discharge path 139, and the cleaning is performed by opening the electric valve on the cleaning means 138 to allow the cleaning water to flow into (and then be discharged from) the sampling tank 131. Note that the cleaning process may be one that repeatedly drains the sampling tank 131 after storing a predetermined amount of cleaning water therein a plurality of times (when storing the predetermined amount of cleaning water, the cleaning water may be circulated by the circulation path 137, etc.).

[0044] FIG. 8 is a flowchart showing an outline of the processing operation of the SV automatic measurement executed in step 605 of FIG. 6. First, a predetermined amount of the mixed liquid in the aeration tank 25 is allowed to flow into the sampling tank 131 (step 801). Basically, it is the same processing concept as step 701 in FIG. 7, but here, the sampling of the mixed liquid from the aeration tank 25 is performed using only the downstream sampling path 1322. When a predetermined amount of the mixed liquid is sampled, it is left standing for a predetermined time (for example, 30 minutes) (step 802). After the predetermined time of standing, the sampling tank containing the mixed liquid left standing is photographed by the camera 135 (step 803). As shown in the conceptual diagram in FIG. 9(b), an interface appears in the mixed liquid in the sampling tank due to the sedimentation of the activated sludge, and this can be used as information indicating the SV by photographing it. Note that a memory indicating the ratio corresponding to the amount of the mixed liquid to be sampled may be attached to the sampling tank, and the camera 135 may be configured to photograph the memory, so that the information indicating the SV can be made easier to understand. Also, not only simply photographing, but also automatically discriminating the position of the interface by image recognition of the photographed image data, and automatically calculating the ratio of the position of the interface to the sampled mixed liquid (i.e., the SV itself) may be performed. When the photographing by the camera (acquisition of information indicating the SV) is completed, the drainage and cleaning process of the sampling tank 131 (step 804) is performed to end the Rr measurement process. The drainage and cleaning process of the sampling tank 131 is the same processing concept as step 708 in FIG. 7.

[0045] As described above, according to the pollution load remote monitoring system 1' of the present embodiment, the oxygen utilization rate (Rr) and the activated sludge sedimentation rate (SV) of the mixed liquid in the aeration tank can be automatically acquired (and logged) almost in real time, and can be remotely monitored. In the present embodiment, only the point of receiving information (Rr, SV) for the information processing device 4 has been described, but of course, it may be possible to access the remote monitoring device 11 from the information processing device 4 and refer to the information indicating Rr and SV logged.

[0046] In the present embodiment, the Rr, SV automatic measuring device 13 is taken as an example of a device that measures both Rr and SV, but the present invention is not limited to this. For example, a measuring device for Rr and a measuring device for SV may be provided separately. FIG. 9 shows an example in which the measuring device for Rr and the measuring device for SV are separated (the same reference numerals are used for the same configurations as the Rr, SV automatic measuring device 13 (FIG. 5)). The Rr automatic measuring device 13' in FIG. 9(a) includes a sampling tank 131, an inflow means 132, an aeration means (aeration nozzle 1331 and blower 1332), a dissolved oxygen concentration meter 134, a water level meter 136, a circulation path 137, a cleaning means 138, and a discharge path 139. Note that the sampling tank in the Rr automatic measuring device 13' does not need to be a transparent container. The SV automatic measuring device 13'' in FIG. 9(b) includes a sampling tank 131, an inflow means 132, a camera 135, a water level meter 136, a cleaning means 138, and a discharge path 139.

[0047] In the present embodiment, the process of automatically measuring the oxygen utilization rate (Rr) and the activated sludge sedimentation rate (SV) of the mixed liquid in the aeration tank 25 is taken as an example to be executed by the control and calculation unit 111 of the remote monitoring device, but the present invention is not limited to this. By providing a control unit or the like in the Rr automatic measuring device or the SV automatic measuring device, the process of automatically measuring Rr or the process of automatically measuring SV may be executed in the Rr automatic measuring device or the SV automatic measuring device.

[0048] In addition, in each embodiment (FIG. 1 and FIG. 4), it is described that the remote monitoring device 11 is arranged at the site where the wastewater treatment facility 2 is located. Therefore, an example is given in which the process of calculating the BOD conversion value based on the measured values of the turbidimeter and the conductivity meter is performed at the site where the wastewater treatment facility 2 is located. However, the present invention is not limited to this. For example, the process of calculating the BOD conversion value based on the measured values of the turbidimeter and the conductivity meter may be executed on a server or the like on the Internet 3 (cloud). (In this case, the server will function as an arithmetic unit for calculating the BOD conversion value based on the measured values of the turbidimeter and the conductivity meter). Also, the process of calculating the BOD conversion value may be performed locally, and then the calculated BOD conversion value may be logged on a server or the like on the Internet 3 (cloud), and the information processing device 4 may access the server to obtain information. The same applies to the process of automatically measuring Rr and the process of automatically measuring SV. These processes may be executed on a server or the like on the Internet 3 (cloud) that has received the measured values obtained at the site. (Of course, those that require physical on-site operation are executed at each site), or the data may be held on a server or the like on the Internet 3 (cloud). In addition, the "pollution load monitoring system" according to the present invention, which can automatically acquire and monitor the BOD conversion value (pollution load information) of the influent water flowing into the aeration tank, does not necessarily have to be a remote monitoring system via the Internet or the like, and may be a system constructed locally on-site. The same applies to the Rr automatic measuring device or the SV automatic measuring device. They do not necessarily have to be a remote monitoring system via the Internet or the like, and may be a system constructed locally on-site.

Explanation of Reference Numerals

[0049] 1... Pollution load remote monitoring system (pollution load monitoring system) 11... Remote monitoring device (computing device) 12... Aeration tank influent water monitoring tank 122... Turbidimeter 123... Conductivity meter 13... Rr, SV automatic measurement device 131... Sampling tank 132... Inflow means 1331... Aeration nozzle (aeration means) 1332... Blower (aeration means) 134... Dissolved oxygen concentration meter 135... Camera 2... Wastewater treatment facility 25... Aeration tank 3... Network 4... Information processing device

Claims

1. A monitoring system for acquiring pollution load information in a wastewater treatment facility equipped with an aeration tank, A turbidity meter for measuring the turbidity of the aeration tank inflow water, which is the inflow water to the aeration tank; a conductivity meter for measuring the conductivity of the aeration tank inflow water; A calculation device that calculates a BOD equivalent value based on the measurements of the turbidity meter and the conductivity meter; Equipped with First correlation information, which is correlation information between the measurement values ​​of the turbidity meter and the conductivity meter and COD, and second correlation information, which is correlation information between COD and BOD, are set in advance, the first correlation information is a multiple regression equation, the multiple regression equation having a first multiple regression equation and a second multiple regression equation; calculating a COD equivalent value using the first multiple regression equation based on the measurement values ​​of the turbidity meter and the conductivity meter, and if the calculated COD equivalent value is equal to or greater than a threshold value, calculating the COD equivalent value again using the second multiple regression equation based on the measurement values ​​of the turbidity meter and the conductivity meter; A pollution load monitoring system that calculates the BOD equivalent value based on the COD equivalent value using the second correlation information.

2. 2. The pollution load monitoring system according to claim 1, wherein, when the BOD converted value exceeds a predetermined value, alarm information is output.

3. A pollution load monitoring system as described in claim 1, which outputs an instruction to change the operating conditions of the wastewater treatment facility when the BOD conversion value exceeds a predetermined value.

4. A pollution load monitoring system as described in any one of claims 1 to 3, wherein when the measurement value of the turbidity meter exceeds a predetermined value, or when the measurement value of the turbidity meter changes by more than a predetermined value within a predetermined time, the measurement value is not used.

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