JP5599169B2 - Water quality sensor, wastewater treatment equipment, wastewater treatment system - Google Patents

Description

  The present invention relates to a water quality sensor, a wastewater treatment apparatus, and a wastewater treatment system.

  Conventionally, water quality sensors have been used to measure water quality. As water quality sensors, for example, turbidity sensors and pH sensors are known. Such a water quality sensor is used, for example, for measuring water quality in rivers, lakes, and oceans, and for measuring water quality in wastewater treatment devices (for example, septic tanks) that treat wastewater such as domestic wastewater and industrial wastewater. In addition, various signal processing devices (for example, data loggers) that process signals obtained from water quality sensors are also used.

JP 2008-49250 A JP 2009-80072 A

  A general water quality sensor is made assuming that measurement with high resolution is required, and is often configured using high-performance components. High performance components include, for example, a detection element (for example, an optical sensor) that exhibits good linearity over a wide input range, and a signal processing circuit (for example, a detection element having a small distortion over a wide input range). An amplifier for amplifying the output signal). As a result, the cost of the water quality sensor often increases. In addition, the case where water quality measurement is performed is not limited to the case where a precise (high resolution) measurement result is required, and it is only necessary to be able to specify an approximate water quality (for example, an approximate treatment state of a wastewater treatment apparatus). If you want to check). In this case, the performance of the water quality sensor was excessive. In addition, in order to process an output signal representing a measurement result (for example, an analog output signal from a water quality sensor), a signal processing device (for example, an analog-to-digital (AD) converter or an analog signal logger) that can perform signal processing with high resolution. ) May be required. The performance of such a signal processing device may be excessive, and the cost may increase due to the use of such a signal processing device.

  The main advantage of the present invention is to provide a technique capable of easily obtaining and using water quality information, which is information relating to water quality.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or modes .
[ Form 1 ]
A water quality sensor that obtains water quality information, which is information about the quality of water to be measured,
A light emitting element that emits light and irradiates the measurement target water with light;
N light receiving elements (N is an integer of 2 or more and 5 or less) that receive the light from the light emitting element through the measurement target water and detect the light receiving intensity that is the intensity of the received light; ,
A determination unit configured to execute, for each of the N light receiving elements, a determination as to whether or not a threshold condition that the received light intensity is larger than a threshold value previously associated with the light receiving elements is satisfied;
Based on the N determination results obtained using the N light receiving elements, N binary information respectively representing the N determination results as the water quality information is represented by the N binary values. A binary information output unit for outputting to a data recording device for recording information;
With
The N light receiving elements are arranged such that a distance between the light emitting element and the light receiving element is different between the N light receiving elements.
Water quality sensor.

[Aspect 1]
A water quality sensor that obtains water quality information, which is information about the quality of water to be measured,
A light emitting element that emits light and irradiates the measurement target water with light;
A light receiving element that receives the light from the light emitting element via the water to be measured and detects a light receiving intensity that is an intensity of the received light;
A determination unit that determines whether or not a threshold condition that the received light intensity is larger than a predetermined threshold is satisfied;
A light emission control unit that changes the light emission intensity of the light emitting element in N stages (N is an integer of 2 or more);
A water quality information output unit that outputs the water quality information based on N determination results obtained by irradiating the measurement target water with light of each of the N levels of emission intensity;
Water quality sensor with.
According to this configuration, since the water quality information is output based on the results of N determinations obtained using the N-level emission intensity, the water quality information can be easily obtained compared to the case of performing high-resolution measurement. You can get it.

[Aspect 2]
A water quality sensor that obtains water quality information, which is information about the quality of water to be measured,
A light emitting element that emits light and irradiates the measurement target water with light;
N light receiving elements that receive the light from the light emitting element through the measurement target water and detect a light receiving intensity that is an intensity of the received light (N is an integer of 2 or more);
A determination unit configured to execute, for each of the N light receiving elements, a determination as to whether or not a threshold condition that the received light intensity is larger than a threshold value previously associated with the light receiving elements is satisfied;
A water quality information output unit that outputs the water quality information based on N determination results obtained by using the N light receiving elements;
With
The N light receiving elements are arranged such that a distance between the light emitting element and the light receiving element is different between the N light receiving elements.
Water quality sensor.
According to this configuration, the water quality information is output based on N determination results obtained by using N light receiving elements having different distances to the light emitting elements. In comparison, water quality information can be easily obtained.

[Aspect 3]
The water quality sensor according to aspect 2, further comprising:
A threshold setting unit configured to set the threshold value of each of the N light receiving elements such that the threshold value increases as the distance between the light emitting element and the light receiving element increases.
Water quality sensor.
According to this configuration, the longer the distance, the larger the threshold value, so that the range of water quality covered by the N determinations can be expanded.

[Aspect 4]
A water quality sensor that obtains water quality information, which is information about the quality of water to be measured,
A light emitting element that emits light and irradiates the measurement target water with light; and a light receiving element that receives the light from the light emitting element through the measurement target water and detects a received light intensity that is the intensity of the received light. N pairs (N is an integer of 2 or more),
A determination unit configured to execute, for each of the N light receiving elements, a determination as to whether or not a threshold condition that the received light intensity is larger than a threshold value previously associated with the light receiving elements is satisfied;
A light emission control unit that sets the light emission intensity of each of the N light emitting elements so that the light emission intensity of the light emitting elements is different among the N light emitting elements;
A water quality information output unit that outputs the water quality information based on N determination results obtained using the N pairs;
Water quality sensor with.
According to this configuration, since the water quality information is output based on the results of N determinations obtained using N pairs with different emission intensities, it is easier than in the case of performing high-resolution measurement. Water quality information can be acquired.

[Aspect 5]
A water quality sensor that obtains water quality information, which is information about the quality of water to be measured,
A light emitting element that emits light and irradiates the measurement target water with light; and a light receiving element that receives the light from the light emitting element through the measurement target water and detects a received light intensity that is the intensity of the received light. N pairs (N is an integer of 2 or more),
A determination unit configured to determine whether or not a threshold condition that the received light intensity is larger than a threshold value associated with the light receiving element is satisfied for each of the N light receiving elements;
A threshold value setting unit for setting the threshold values of the N light receiving elements so that the threshold values are different from each other among the N light receiving elements;
A water quality information output unit that outputs the water quality information based on N determination results obtained using the N pairs;
Water quality sensor with.
According to this configuration, since the water quality information is output based on the results of N determinations obtained using N pairs with different threshold values, the water quality can be more easily compared with the case where high-resolution measurement is performed. Information can be acquired.

[Aspect 6]
A water quality sensor that obtains water quality information, which is information about the quality of water to be measured,
N light emitting elements that emit light and irradiate the measurement target water with light (N is an integer of 2 or more);
A light receiving element that receives the light from the light emitting element via the water to be measured and detects a light receiving intensity that is an intensity of the received light;
A determination unit that determines whether or not a threshold condition that the received light intensity is larger than a predetermined threshold is satisfied;
A light emission control unit that sets the light emission intensity of each of the N light emitting elements so that the light emission intensity of the light emitting elements is different among the N light emitting elements;
A water quality information output unit that outputs the water quality information based on N determination results obtained using each of the N light emitting elements;
Water quality sensor with.
According to this configuration, the water quality information is output based on the results of N determinations obtained using each of the N light emitting elements having different light emission intensities, so that compared with the case of performing high-resolution measurement. Water quality information can be easily acquired.

[Aspect 7]
A water quality sensor that obtains water quality information, which is information about the quality of water to be measured,
N light emitting elements that emit light and irradiate the measurement target water with light (N is an integer of 2 or more);
A light receiving element that receives the light from the light emitting element via the water to be measured and detects a light receiving intensity that is an intensity of the received light;
A determination unit that determines whether or not a threshold condition that the received light intensity is larger than a predetermined threshold is satisfied;
A water quality information output unit that outputs the water quality information based on N determination results obtained using the N light emitting elements;
With
The N light emitting elements are arranged such that a distance between the light emitting element and the light receiving element is different between the N light emitting elements.
Water quality sensor.
According to this configuration, water quality information is output based on N determination results obtained by using N light emitting elements having different distances to the light receiving element, so that compared with the case of performing high-resolution measurement. Thus, water quality information can be easily acquired.

[Aspect 8]
The water quality sensor according to aspect 7, further comprising:
A light emission control unit that sets the light emission intensity of each of the N light emitting elements so that the light emission intensity of the light emitting element decreases as the distance between the light emitting element and the light receiving element increases.
Water quality sensor.
According to this configuration, the longer the distance is, the smaller the emission intensity is, so the range of water quality covered by the N determinations can be expanded.

[Aspect 9]
A water quality sensor that obtains water quality information, which is information about the quality of water to be measured,
A light emitting element that emits light and irradiates the measurement target water with light;
N light receiving elements that receive the light from the light emitting element through the measurement target water and detect a light receiving intensity that is an intensity of the received light (N is an integer of 2 or more);
A determination unit configured to execute, for each of the N light receiving elements, a determination as to whether or not a threshold condition that the received light intensity is larger than a threshold value previously associated with the light receiving elements is satisfied;
A threshold value setting unit for setting the threshold values of the N light receiving elements so that the threshold values are different from each other among the N light receiving elements;
A water quality information output unit that outputs the water quality information based on N determination results obtained by using the N light receiving elements;
Water quality sensor with.
According to this configuration, since water quality information is output based on N determination results obtained using N light receiving elements having different threshold values, it is simpler than when high-resolution measurement is performed. Water quality information can be acquired.

[Aspect 10]
A water quality sensor that obtains water quality information, which is information about the quality of water to be measured,
A light emitting element that emits light and irradiates the measurement target water with light; and a light receiving element that receives the light from the light emitting element through the measurement target water and detects a received light intensity that is the intensity of the received light. N pairs (N is an integer of 2 or more),
A determination unit configured to execute, for each of the N light receiving elements, a determination as to whether or not a threshold condition that the received light intensity is larger than a threshold value previously associated with the light receiving elements is satisfied;
A water quality information output unit that outputs the water quality information based on N determination results obtained using the N pairs;
With
The light emitting element and the light receiving element of each of the N sets of pairs are arranged such that a distance between the light emitting element and the light receiving element is different between the N sets of pairs.
Water quality sensor.
According to this configuration, the water quality information is output based on the results of N determinations obtained by using N pairs with different distances between the light emitting element and the light receiving element, so high-resolution measurement is possible. Water quality information can be easily acquired compared to the case where it is performed.

[Aspect 11]
The water quality sensor according to aspect 10, further comprising:
A light emission control unit that sets the light emission intensity of each of the N light emitting elements so that the light emission intensity of the light emitting element decreases as the distance between the light emitting element and the light receiving element increases.
Water quality sensor.
According to this configuration, the longer the distance is, the smaller the emission intensity is, so the range of water quality covered by the N determinations can be expanded.

[Aspect 12]
The water quality sensor according to aspect 10 or aspect 11, further comprising:
A threshold setting unit configured to set the threshold value of each of the N light receiving elements such that the threshold value increases as the distance between the light emitting element and the light receiving element increases.
Water quality sensor.
According to this configuration, the longer the distance, the larger the threshold value, so that the range of water quality covered by the N determinations can be expanded.

[Aspect 13]
A water quality sensor that obtains water quality information, which is information about the quality of water to be measured,
A light emitting element that emits light and irradiates the measurement target water with light;
A light receiving element that receives the light from the light emitting element via the water to be measured and detects a light receiving intensity that is an intensity of the received light;
A determination unit for determining whether or not a threshold condition that the received light intensity is larger than a threshold is satisfied;
A threshold setting unit that changes the threshold in N stages (N is an integer of 2 or more);
A water quality information output unit that outputs the water quality information based on N determination results obtained by using each of the N-stage threshold values;
A water quality sensor.
According to this configuration, since the water quality information is output based on the results of N determinations obtained by using each of the N-stage threshold values, the water quality can be easily compared with the case of performing high-resolution measurement. Information can be acquired.

[Aspect 14]
A water quality sensor that obtains water quality information, which is information about the quality of water to be measured,
A light emitting element that emits light and irradiates the measurement target water with light;
A light receiving element that receives the light from the light emitting element via the water to be measured and detects a light receiving intensity that is an intensity of the received light;
A determination unit that determines whether or not a threshold condition that the received light intensity is larger than a predetermined threshold is satisfied;
A water quality information output unit that outputs the water quality information based on the N determination results (N is 1);
Water quality sensor with.
According to this configuration, since the water quality information is output based on the determination result whether or not the threshold condition that the received light intensity is larger than the predetermined threshold value is satisfied, it is compared with the case where high-resolution measurement is performed. Thus, water quality information can be easily acquired.

[Aspect 15]
The water quality sensor according to any one of aspects 1 to 14,
The water quality information output unit includes a binary information output unit that outputs N binary information respectively representing the N determination results as the water quality information.
Water quality sensor.
According to this configuration, since the water quality information can be processed using the processing apparatus capable of processing binary information, the water quality information can be easily used.

[Aspect 16]
The water quality sensor according to any one of aspects 1 to 15,
The water quality information output unit includes a notification unit that performs notification to the user of the water quality information as the output of the water quality information,
The notification unit is information determined based on the results of the N determinations, and notifies the user of the information indicating the water quality at the N + 1 stage as the water quality information.
Water quality sensor.
According to this configuration, the user can easily check the water quality represented in the (N + 1) stage based on the notified water quality information, and thus can easily use the water quality information.

[Aspect 17]
Wastewater treatment equipment,
A water treatment unit for purifying wastewater;
17. The water quality sensor according to any one of aspects 1 to 16, wherein the light emitting element and the light receiving element are arranged in a water flowing portion that is a target of acquisition of water quality information in the water treatment unit. When,
A wastewater treatment apparatus comprising:
According to this structure, the water quality information regarding the water quality of the target water in the water treatment unit can be easily acquired.

[Aspect 18]
A wastewater treatment system,
Wastewater treatment equipment of M groups (M is an integer of 2 or more) installed apart from each other;
A management device for managing each of the M wastewater treatment devices;
With
Each of the M wastewater treatment devices is
A water treatment unit for purifying the waste water;
The water quality sensor according to aspect 15, wherein the light emitting element and the light receiving element are arranged in a water flowing portion that is a target of acquisition of water quality information in the water treatment unit,
A transmission unit for transmitting data representing the N pieces of binary information output by the binary information output unit to the management device;
With
The management device
A receiving unit for receiving data representing the N pieces of binary information transmitted by the transmitting unit of each of the M wastewater treatment devices;
A data processing unit for processing the received data;
Equipped with a wastewater treatment system.
According to this structure, the water quality information regarding the water quality in a plurality (M bases) of wastewater treatment apparatuses can be easily acquired. Moreover, since the management apparatus receives N pieces of binary information as water quality information, it is not necessary to increase the processing capability required for the management apparatus compared to the case where the water quality information is expressed with high resolution. As a result, water quality information can be easily used.

[Aspect 19]
The wastewater treatment system according to aspect 18,
The data processing unit is information determined based on the N pieces of binary information represented by the received data, and informs the user of the information indicating the water quality in the N + 1 stage.
Wastewater treatment system.
According to this configuration, the user can easily confirm the water quality represented in the N + 1 stage based on the notified water quality information, so even if the number of waste water treatment devices is large, the water quality in each waste water treatment device. Can be easily grasped.

[Aspect 20]
The wastewater treatment system according to aspect 18 or aspect 19,
The management device further includes a recording unit for recording data,
The data processing unit records a history of the binary information represented by the received data in the recording unit;
Wastewater treatment system.
According to this configuration, it is possible to easily manage the wastewater treatment apparatus using the history of changes in water quality.

  The present invention can be realized in various forms, and includes, for example, a water quality sensor that acquires water quality information that is information about water quality, a method that acquires water quality information that is information about water quality, and the water quality sensor. It can be realized in the form of a wastewater treatment device, a wastewater treatment system having a plurality of wastewater treatment devices and a management device, or the like.

It is explanatory drawing which shows the water quality sensor as one Example of this invention. 3 is a block diagram showing a configuration of a water quality sensor 300. FIG. It is a table | surface which shows the relationship between three determination results and water quality. It is explanatory drawing which shows the state of the display panel 280 according to water quality. It is explanatory drawing which shows an example of the waste water treatment apparatus which has the water quality sensor. It is explanatory drawing which shows arrangement | positioning of the sensor unit 100 in the sedimentation tank 816. FIG. It is a timing chart which shows acquisition of water quality information. It is explanatory drawing of the wide area water quality management system 1100 using the waste water treatment apparatus 900 (FIG. 5, FIG. 6). It is explanatory drawing which shows another Example of a water quality sensor. It is a table | surface which shows the relationship between three determination results similar to FIG. 3, and water quality. It is a timing chart which shows acquisition of water quality information. It is explanatory drawing which shows another Example of a water quality sensor. It is explanatory drawing which shows another Example of a water quality sensor. It is a table | surface which shows the relationship between three determination results similar to FIG. 10, and water quality. It is explanatory drawing which shows another Example of a water quality sensor. It is explanatory drawing which shows another Example of a water quality sensor.

  Next, an embodiment of the present invention will be described based on first to seventh examples and modifications.

A. First embodiment:
FIG. 1 is an explanatory view showing a water quality sensor as one embodiment of the present invention. The water quality sensor 300 is a sensor that acquires information on water quality (hereinafter referred to as “water quality information”). The water quality sensor 300 includes a rod-shaped sensor unit 100 and a control unit 200 connected to one end of the sensor unit 100 via a cable 12. A recess 120 is formed at the other end of the sensor unit 100. The inner surface of the recess 120 includes a first wall 122 and a second wall 124 that faces the first wall 122. These walls 122 and 124 extend to the side surface of the sensor unit 100, and the recess 120 penetrates when viewed from the side surface of the sensor unit 100. A light emitting element 130 is provided on the first wall 122, and a light receiving element 140 is provided on the second wall 124 at a position facing the light emitting element 130. On the other hand, the control unit 200 includes a terminal panel 260 and a display panel 280. The terminal panel 260 is provided with three sets of terminal pairs 261 to 263. The display panel 280 is provided with three lamps 281 to 283 (for example, light emitting diodes).

FIG. 2 is a block diagram showing the configuration of the water quality sensor 300. In order to acquire the water quality information of the measurement target water 10, the sensor unit 100 (particularly the recess 120) is immersed in the measurement target water 10. Thereby, the measurement target water 10 is introduced into the recess 120. In this state, the light emitting element 130 emits light. The light from the light emitting element 130 attenuates through the measurement target water 10, and the attenuated light enters the light receiving element 140. Causes of light attenuation include light absorption and scattering by the measurement target water 10. The measurement target water 10 may contain various components that cause a decrease in water quality (for example, organic matter, nitrogen compounds (ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, etc.), phosphorus compounds, etc.). The higher the concentration of such components, the stronger the light attenuation. Accordingly, the water quality is worse as the intensity of light received by the light receiving element 140 (hereinafter referred to as “light receiving intensity RI”) is smaller than the intensity of light emitted from the light emitting element 130 (hereinafter referred to as “light emission intensity EI”). (In other words, it can be said that the higher the transmittance of the water 10 to be measured, the better the water quality). In addition, what is necessary is just to employ | adopt energy amount (for example, W / cm < ² >) per unit time and unit area as intensity | strength of light.

  The intensity of attenuation (transmittance) can vary depending on the wavelength of light. And the wavelength dependence changes according to the component contained in the water 10 to be measured. For example, when the measurement target water 10 contains nitrate ions, the higher the concentration of nitrate ions, the more the ultraviolet light (for example, light having a wavelength of 220 nm) is absorbed and the attenuation is strong (the transmittance is low). It is known. Moreover, the attenuation of near infrared light (for example, light with a wavelength of 700 to 1000 nm) increases as the BOD (biochemical oxygen demand) caused by SS (floating matter) or organic matter contained in the measurement target water 10 increases. It is known to be strong. In this embodiment, a light emitting diode that emits near infrared light is used as the light emitting element 130, and a photodiode capable of detecting the intensity of near infrared light is used as the light receiving element 140. Thereby, the water quality information (intensity of attenuation of light) regarding BOD of measurement object water 10 is acquirable.

  The water quality items represented by the water quality information are not limited to BOD and nitrate ion concentration, and various items such as turbidity, transparency, and amount of SS (floating matter) can be adopted. And the wavelength of the light utilized for the detection of the intensity of attenuation may be experimentally determined beforehand according to the item of water quality. In either case, various configurations can be adopted as a configuration for using light having a wavelength suitable for the water quality item. For example, a light emitting element that selectively emits light having a suitable wavelength may be used, or a light receiving element that selectively detects the intensity of light having a suitable wavelength may be used. Between these, a filter that selectively transmits light of a suitable wavelength may be disposed. Moreover, as a light emitting element, not only a light emitting diode but various light emitting elements (for example, discharge lamp) are employable. The light receiving element is not limited to a photodiode, and various light receiving elements (for example, a photoresistor or a phototransistor) that can detect the intensity of received light can be used.

  The control unit 200 includes a light emission control unit 210, a determination unit 220, a water quality information output unit 230, a terminal panel 260, a display panel 280, and an operation panel 290. In the present embodiment, the processing units 210, 220, and 230 of the control unit 200 are configured using dedicated electronic circuits, respectively.

  The operation panel 290 includes operation means (for example, a switch and a button) (not shown) for the user to operate. Each element 210, 220, 230 of the control unit 200 executes various processes in accordance with a user instruction input to the operation panel 290.

  The light emission control unit 210 is a power supply circuit that supplies power to the light emitting element 130 to cause the light emitting element 130 to emit light. In addition, the light emission control unit 210 controls the light emission intensity EI of the light emitting element 130. As a configuration for controlling the emission intensity EI, any configuration suitable for the light emitting element 130 can be adopted. For example, when the light emission intensity EI is determined according to the current flowing through the light emitting element 130, a power supply circuit capable of controlling the current may be employed.

  The determination unit 220 is a circuit that determines whether or not the threshold condition that the received light intensity RI detected by the light receiving element 140 is larger than the threshold is satisfied. As a circuit configuration for determination, any configuration suitable for the light receiving element 140 can be employed. For example, when the current flowing through the light receiving element 140 is determined according to the light receiving intensity RI, a circuit for obtaining a voltage according to the current flowing through the light receiving element 140, the voltage and a reference voltage (corresponding to a threshold value of the light receiving intensity RI). It is possible to employ a comparator circuit that compares (voltage). When the resistance value of the light receiving element 140 is determined according to the received light intensity RI, a circuit that acquires a voltage according to the resistance value of the light receiving element 140 and a comparator circuit that compares the voltage with a reference voltage can be employed. It is.

  In the present embodiment, the light emission control unit 210 changes the light emission intensity EI in three stages of a predetermined first level LV1 (weak), second level LV2 (medium), and third level LV3 (strong). Let Then, the determination unit 220 performs determination using a predetermined threshold for each of the three levels of light emission intensity LV1, LV2, and LV3. That is, in this embodiment, three determinations are made for obtaining water quality information once.

  FIG. 3 is a table showing the relationship between the three determination results and the water quality. In the figure, the determination result is represented by either “◯” or “×”. “◯” indicates that the threshold condition is satisfied (the received light intensity RI is greater than the threshold), and “X” indicates that the threshold condition is not satisfied (the received light intensity RI is equal to or less than the threshold). ing. In the present embodiment, since the same threshold value is commonly used for the three determinations, the better the water quality of the measurement target water 10, the smaller the minimum light emission intensity that can obtain the determination result “◯”. Therefore, the three determination results represent the outline of the water quality in four stages. Specifically, it can be said that the higher the total number of determination results of “◯” (four stages of 0 to 3), the better the water quality. In other words, it can be said that the weakest emission intensity EI from which the determination result of “◯” is obtained represents the water quality in four stages (in FIG. 3, it is indicated by a double line). Have been). When all the determination results are “x”, it is evaluated that the water quality is the worst. It can also be said that the strongest emission intensity EI of the emission intensity EI from which the determination result of “x” was obtained represents the water quality in four stages (in FIG. 3, it is indicated by a triple line). ) When all the determination results are “◯”, it is evaluated that the water quality is the best. In FIG. 3, the water quality is classified into four stages of “good”, “normal”, “careful”, and “bad”.

  In addition, the three-step emission intensity LV1, LV2, LV3 is a four-step water quality evaluation that is better than a water quality reference value (for example, BOD = 20 mg / L) and a water quality evaluation worse than the reference value. May be experimentally determined in advance so as to include. For example, the first level LV1 corresponds to BOD = 10 mg / L, the second level LV2 corresponds to BOD = 20 mg / L, and the third level LV3 corresponds to BOD = 40 mg / L. LV3 may be determined. In this case, if the determination result at the third level LV3 and the second level LV2 is “◯”, it can be determined that the water quality satisfies the reference value of BOD (in addition, at the third level LV3) If the determination result at the second level LV2 is “◯” without referring to the determination result, it may be determined that the water quality satisfies the reference value of BOD). When the determination result at the second level LV2 is “x”, it can be determined that the water quality is lower than the reference value of BOD.

  The water quality information output unit 230 of the control unit 200 (FIG. 2) is a circuit that outputs water quality information based on three determination results. In the present embodiment, the water quality information output unit 230 includes a binary information output unit 240 and a notification unit 270.

  The binary information output unit 240 has three switches 251, 252 and 253. Each of these switches 251, 252, and 253 forms a so-called contact output. The binary information output unit 240 controls the three switches 251, 252, and 253 so as to represent the determination results of the three light emission intensities LV1, LV2, and LV3. In this embodiment, turning on the switch (closing the contact) indicates that the threshold condition is met. However, the switch off (contact open) may represent the establishment of the threshold condition. The switches 251, 252, and 253 are connected to terminal pairs 261, 262, and 263, respectively. The binary information output unit 240 outputs information (open / close of contacts) representing three determination results to an external device (for example, a data logger) through the terminal pairs 261, 262, and 263. Information output by the three contact outputs corresponds to “water quality information”.

  Three lamps 281, 282, and 283 are connected to the notification unit 270. The notification unit 270 controls the lighting states of the three lamps 281, 282, and 283 so as to represent the determination results of the three light emission intensities LV 1, LV 2, and LV 3. In the present embodiment, the lamp lighting represents the establishment of the threshold condition. However, the lamp turn-off may represent the establishment of the threshold condition.

  FIG. 4 is an explanatory diagram showing the state of the display panel 280 according to the water quality. In the figure, states 280A, 280B, 280C, and 280D of the display panel 280 corresponding to each of the four levels of water quality (“good”, “normal”, “caution”, and “bad”) are shown. In the figure, the hatched lamps 281 to 283 indicate “off”, and the non-hatched lamps 281 to 283 indicate “lit”. The user can easily check the water quality simply by observing the lighting states of the three lamps 281 to 283 (for example, the total number of lamps that are lit). In particular, since it is not necessary to read the detailed display of the value of the water quality item (for example, the scale of an analog meter or a numerical value with a large number of digits), it is easy to check the outline of the water quality.

  FIG. 5 is an explanatory view showing an example of a wastewater treatment apparatus having a water quality sensor 300. In this embodiment, the waste water treatment apparatus 900 includes a water treatment tank 800, a water quality sensor 300 (the sensor unit 100 and the control unit 200), and a data logger 400 connected to the control unit 200. In the wastewater treatment apparatus 900, the water quality sensor 300 is permanently installed, and water quality information is continuously acquired.

  The water treatment tank 800 is a device that purifies wastewater from a general household (such a device is also called a “septic tank”). The water treatment tank 800 has a plurality of water treatment regions (also referred to as “water treatment mechanisms”) in order to perform purification treatment through a plurality of steps. In the embodiment of FIG. 5, the water treatment tank 800 includes a contaminant removal tank 810, an anaerobic filter bed tank 812, a contact aeration tank 814, a precipitation tank 816, and a disinfection tank 818 in order from the upstream (left side in FIG. 5). Contains a water treatment area. The waste water that has flowed into the water treatment tank 800 is sequentially treated in a contaminant removal tank 810, an anaerobic filter bed tank 812, a contact aeration tank 814, a precipitation tank 816, and a disinfection tank 818, and then discharged to the outside of the water treatment tank 800. The Hereinafter, water flowing through each water treatment area is referred to as “water to be treated” or simply “water”.

  The contaminant removal tank 810 is a water treatment region that separates contaminants in the waste water from the water to be treated. The waste water from the inflow port 802 first flows into the contaminant removal tank 810. The contaminant removal tank 810 has solid-liquid separation means such as an inflow baffle (not shown), and separates contaminants in the waste water from the water to be treated. The water after the impurities are separated (removed) is transferred to the anaerobic filter bed tank 812.

  The anaerobic filter bed tank 812 is a water treatment region for performing anaerobic treatment with anaerobic microorganisms. The anaerobic filter bed tank 812 has a filter medium (not shown) for attaching anaerobic microorganisms. The organic matter in the for-treatment water is decomposed by the anaerobic treatment. Moreover, the filter medium can capture suspended matters in the water to be treated. The water treated in the anaerobic filter bed tank 812 is transferred to the contact aeration tank 814.

  The contact aeration tank 814 is a water treatment area for performing an aerobic treatment with an aerobic microorganism. The contact aeration tank 814 has a contact material (not shown) for attaching aerobic microorganisms. Air is supplied to the contact aeration tank 814 by a blower (blower) (not shown). Aerobic microorganisms use oxygen contained in the air to decompose organic matter in the water to be treated. The water treated in the contact aeration tank 814 is transferred to the settling tank 816. A part of the water treated in the contact aeration tank 814 may be transferred (circulated) to the contaminant removal tank 810. In this way, suspended substances (eg, sludge) present in the contact aeration tank 814 can be transferred to the contaminant removal tank 810.

  The sedimentation tank 816 is a water treatment region in which water transferred from the contact aeration tank 814 is temporarily retained to precipitate and separate suspended substances in water. The water treated in the settling tank 816 is transferred to the disinfection tank 818.

  The disinfection tank 818 is a water treatment area for disinfecting water to be treated. The disinfection tank 818 has a medicine cylinder filled with a disinfectant (for example, a solid chlorine agent) (not shown). In the disinfection tank 818, the water to be treated comes into contact with the disinfectant, and the water to be treated is disinfected by the disinfectant. The sterilized water is discharged to the outside of the water treatment tank 800 through the outlet 804.

  In the present embodiment, the sensor unit 100 is disposed in the settling tank 816. A data logger 400 is connected to the control unit 200. The data logger 400 records the quality of water to be treated in the settling tank 816 (that is, the quality of water after being treated by the contact aeration tank 814).

  FIG. 6 is an explanatory view showing the arrangement of the sensor unit 100 in the settling tank 816. In the figure, a settling tank 816 and a disinfection tank 818 are shown. The sensor unit 100 is fixed in a state where it is immersed in the water to be treated in the settling tank 816 on a partition plate 816a that partitions between the settling tank 816 and another water treatment region. Water from the contact aeration tank 814 is transferred to the settling tank 816 through an opening (not shown) formed in the lower part of the partition plate 816a. Further, a disinfection tank 818 is arranged on the downstream side (the right side in FIG. 6) of the upper part of the settling tank 816. Water from the sedimentation tank 816 is transferred to the disinfection tank 818 through an opening (not shown) formed in the wall 818a of the disinfection tank 818.

  FIG. 6 further shows a part of the configuration of the control unit 200 and the configuration of the data logger 400. As described above, the binary information output unit 240 of the control unit 200 outputs information representing the three determination results (contact open / close) through the terminal pairs 261 to 263.

  The data logger 400 includes a data processing unit 410, a recording device 420, a display device 430, an operation panel 440, and a terminal panel 460. The data processing unit 410 is a computer that performs various data processing. The recording device 420 is a non-volatile recording device that records data (for example, a semiconductor memory such as a flash memory or a hard disk drive). The display device 430 is a device that displays information (in this embodiment, a liquid crystal display). The operation panel 440 has operation means (not shown) for operation by the user. The terminal panel 460 is provided with three sets of terminal pairs 461 to 463. The three terminal pairs 461 to 463 are connected to the three terminal pairs 261 to 263 of the control unit 200, respectively.

  The data processing unit 410 executes various processes in accordance with user instructions input to the operation panel 440. For example, the data processing unit 410 continuously records data representing the states of the terminal pairs 461 to 463 (contact open / closed) and the date and time when the states are acquired in the recording device 420. Then, according to a user instruction, the data processing unit 410 displays the data recorded in the recording device 420 on the display device 430.

  FIG. 7 is a timing chart showing the acquisition of water quality information. In the embodiment of FIG. 7, the water quality sensor 300 (FIG. 2) acquires water quality information every hour. In one acquisition, the light emission control unit 210 emits light for a first predetermined time (for example, 5 seconds) at each of the three light emission intensities LV1, LV2, and LV3 for a second predetermined time (for example, 5 seconds). Perform in order with a gap of. The determination unit 220 performs determination regarding each of the three light emission intensities LV1, LV2, and LV3 by acquiring the light reception intensity of the light receiving element 140 in a state where the light emitting element 130 emits light. In the figure, the determination result is represented by either “◯” or “×”. “◯” indicates that the threshold condition is satisfied, and “×” indicates that the threshold condition is not satisfied. In the example of FIG. 7, in the measurement at 17:00, since all three determination results are “◯”, the water quality is “good”. In the measurement at 18:00, since only the determination of the third level LV3 is “◯”, the water quality is “Caution”. In the measurement at 19:00, since only the determination of the second level LV2 and the third level LV3 is “◯”, the water quality is “normal”.

  The data processing unit 410 of the data logger 400 (FIG. 6) records the determination result and the date and time (determination result history) in the recording device 420. In the present embodiment, as shown in FIG. 7, the date and time differs by 10 seconds between the three determinations obtained by one acquisition of water quality information. Further, the data processing unit 410 displays the recorded determination result (the determination result of the date and time instructed by the user) on the display device 430 according to the user's instruction. Any format can be adopted as the display format. For example, you may employ | adopt the timing chart of a determination result like FIG. In this way, the user can easily confirm the water quality at a desired date and time by observing the displayed chart.

  As described above, the water quality sensor 300 of the present embodiment has the following various advantages. Since the water quality sensor 300 outputs the water quality information based on the three determination results obtained by using the three levels of emission intensity, when measuring with high resolution (for example, when using a 12-bit AD converter) Compared with, water quality information can be easily obtained. In this embodiment, instead of evaluating the water quality with high resolution, the outline of the water quality is evaluated in four stages. Therefore, the accuracy (performance) requirements for the light emission control unit 210, the determination unit 220, the light emitting element 130, and the light receiving element 140 can be relaxed as compared with the case where the water quality is evaluated with high resolution. As a result, the configuration of the water quality sensor 300 can be simplified, and water quality information can be easily acquired. Moreover, the cost of the water quality sensor 300 can be reduced. Also, as shown in FIG. 4, the notification unit 270 (FIG. 2) displays each of the three determination results as binary values (turned on / off), so that the configuration of the notification unit 270 can be simplified. The user can easily confirm the water quality represented in four stages from the three determination results. 2 and 6, since the binary information output unit 240 outputs binary information representing the determination result, a simple processing device capable of processing the binary information (for example, the data in FIG. 6). Logger 400) can be used to process water quality information. As described above, since the configuration of the water quality sensor 300 and the data logger 400 can be simplified, the cost can be reduced. As a result, the water quality sensor 300 can be permanently installed in the water treatment tank 800 and the water quality can be continuously monitored over a long period of time at low cost.

B. Second embodiment:
FIG. 8 is an explanatory diagram of a wide area water quality management system 1100 using the waste water treatment apparatus 900 (FIGS. 5 and 6). The wide area water quality management system 1100 includes three wastewater treatment devices 900 installed at three locations L1, L2, and L3 separated from each other, and a management device 1000 that manages water quality information of the wastewater treatment devices 900. ing. In the embodiment of FIG. 8, a communication terminal 500 is added to each waste water treatment apparatus 900. Hereinafter, the entire control unit 200, data logger 400, and communication terminal 500 are also referred to as "control terminal 600".

  The management device 1000 includes a data processing unit 1010, a recording device 1020, a display device 1030, an operation panel 1040, and a communication terminal 1050. The data processing unit 1010 is a computer that performs various data processing. The recording device 1020 is a non-volatile recording device that records data (in this embodiment, a hard disk drive). The display device 1030 is a device that displays information (in this embodiment, a liquid crystal display). The operation panel 1040 has operation means (for example, buttons) (not shown) for the user to operate.

  The communication terminal 500 of each waste water treatment apparatus 900 and the communication terminal 1050 of the management apparatus 1000 can communicate via a communication network. As the communication network, a communication path using at least one of wireless communication and wired communication can be employed. As the communication terminals 500 and 1050, various communication devices can be employed. For example, a mobile phone may be employed. The communication terminal 500 of each waste water treatment apparatus 900 acquires data representing the water quality information and the date and time associated with the water quality information from the data logger 400, and transmits the acquired data to the communication terminal 1050 of the management apparatus 1000. To do. The transmitted water quality information is data representing the contact state (open / close of the contact) input to the three terminal pairs 461 to 463 (FIG. 6). In this embodiment, three binary data (3 Bit). The data processing unit 1010 of the management apparatus 1000 records the received water quality information and the date and time (water quality information history) in the recording device 1020. Then, according to the user's instruction, the data processing unit 1010 displays the data recorded in the recording device 1020 on the display device 1030. Any format can be adopted as the display format. For example, three determination results may be displayed as shown in FIG. 4, or a determination result timing chart as shown in FIG. 7 may be displayed.

  As described in the first embodiment, since the configuration of the water quality sensor 300 and the data logger 400 can be simplified, the cost can be reduced. As a result, the water quality sensor 300 can be permanently installed in the plurality of water treatment tanks 800 and the water quality can be continuously monitored over a long period of time at low cost. In addition, since the water quality information obtained from one water quality sensor 300 is represented by three binary data (3 bits), the amount of data is reduced as compared with the case where the water quality information is represented with high resolution (for example, 12 bits). It can be greatly reduced. As a result, when the management apparatus 1000 processes water quality information from a plurality of wastewater treatment apparatuses 900, the processing capacity required for the management apparatus 1000 (for example, the capacity of the recording apparatus 1020 and the processing speed of the data processing unit 1010). ) Is not high. Thereby, the cost of the wide area water quality management system 1100 can be reduced. Also, as shown in FIGS. 3, 4, and 7, in this embodiment, the water quality information is represented by three binary data, so the water quality information is represented by analog data or high-resolution digital data. Compared with the case where the user (administrator) is, the quality of the water quality (treatment state) of the waste water treatment device 900 can be easily determined from the three determination results (binary data) regardless of experience or skill (presence / absence of abnormality). Can be judged. Therefore, even when water quality information from a plurality of wastewater treatment apparatuses 900 is collected in the management apparatus 1000, the administrator uses the management apparatus 1000 to manage the wastewater treatment regardless of experience or skill. It is possible to easily check the water quality of the apparatus 900 (quality of the treatment state). As a result, an increase in the labor of the manager for managing the waste water treatment apparatus 900 can be suppressed.

  In addition, if the quality of the wastewater treatment device 900 is judged based on the history of water quality information instead of temporarily obtained water quality information, the effect of temporary fluctuations in water quality can be suppressed more appropriately. Judgment is possible. However, in the past, when judging the presence or absence of abnormalities from water quality information that fluctuates from moment to moment, the actual situation is that the judgment is based on the experience of an administrator who is familiar with various fluctuation patterns of water quality information. (Various variation patterns are obtained by using the waste water treatment device 900 under various conditions). In particular, when the water quality information is represented by analog data or high-resolution (for example, 12-bit) digital data, an administrator who does not have sufficient experience determines whether there is an abnormality from the history of water quality information. It was difficult to do. On the other hand, according to the present embodiment, since the water quality information at a certain point in time is represented by three binary data, a simple standard is adopted as a criterion for determining the quality of the treatment state based on the history of the water quality information. Can do. For example, “50% or more of the water quality information obtained in one day indicates“ bad ”” may be adopted as a criterion for determining that the treatment state is abnormal. In this way, when the water quality information is represented by a plurality of (three in this embodiment) binary data, simple judgment criteria can be adopted, so the administrator can Judge easily with the same quality. As a result, even when water quality information from a large number of wastewater treatment apparatuses 900 is collected in the management apparatus 1000, the administrator can easily manage the wastewater treatment apparatuses 900.

  As the determination criteria, various criteria that lead to a determination result by integrating the history of water quality information can be adopted. For example, “the ratio of the water quality information obtained by combining the“ normal ”water quality information and the“ good ”water quality information in the water quality information obtained in one day is 60% or more” is not abnormal. You may adopt as a standard of. As described above, the ratio of the water quality information representing the predetermined water quality in the water quality information obtained within the predetermined period (for example, 1 day, 2 days, or 1 week) and the comparison result with the predetermined threshold value, You may judge the presence or absence.

  The total number of waste water treatment apparatuses 900 is not limited to 3, and may be 2 or 4 or more. In particular, in the present embodiment, since it is possible to easily obtain and use water quality information, more than 100 wastewater treatment apparatuses 900 may be managed. In this embodiment, the recording of the water quality information history to the recording device 1020 may be omitted. Moreover, you may abbreviate | omit the display (notification | report) of the water quality information with respect to a user.

C. Third embodiment:
FIG. 9 is an explanatory view showing another embodiment of the water quality sensor. There are three differences from the water quality sensor 300 shown in FIGS. The first difference is that three light receiving elements 140 a, 140 b, 140 c are provided on the second wall 124. Among these light receiving elements 140a, 140b, and 140c, the distances to the light emitting elements 130 are different from each other. Among the three light receiving elements 140a, 140b, and 140c, the first light receiving element 140a is closest to the light emitting element 130, and the third light receiving element 140c is farthest from the light emitting element 130. The second difference is that the determination unit 220a performs three determinations by comparing the light reception intensities RIa, RIb, and RIc of the three light receiving elements 140a, 140b, and 140c with a common threshold value ( It can also be said that the common threshold value is associated with each of the three light receiving elements 140a, 140b, and 140c in advance). As the configuration of the determination unit 220a, various configurations that perform three determinations using three received light intensities can be employed. For example, the determination unit 220a may use one comparator circuit in common for the three light receiving elements 140a, 140b, and 140c. Instead, the determination unit 220a may include three comparator circuits for the three light receiving elements 140a, 140b, and 140c. In this way, three determinations can be made in parallel. The third difference is that the light emission control unit 210a maintains the light emission intensity EI of the light emitting element 130 at a predetermined value without changing it. The configuration of other elements of the water quality sensor 300a of the present embodiment is the same as the configuration of elements having the same reference numerals of the water quality sensor 300 shown in FIGS. For example, the binary information output unit 240 outputs three determination results by three contact outputs, and the notification unit 270 outputs the three determination results similarly to FIG. In each embodiment described later, the same reference numerals are given to the same elements as those in the previous embodiment, and detailed description thereof is omitted.

  FIG. 10 is a table showing the relationship between three determination results and water quality, similar to FIG. The meanings of the marks (“◯” and “x”) representing the determination result are the same as the meanings of the same marks in FIG. In the present embodiment, the same light emission intensity EI is commonly used for the three determinations. Accordingly, the light receiving intensity decreases as the distance from the light emitting element 130 to the light receiving element increases (RIa> RIb> RIc). And the better the water quality, the longer the shortest distance at which the determination result of “◯” can be obtained. Therefore, as in the embodiment of FIG. 3, the three determination results represent the water quality in four stages. Specifically, the water quality is better as the total number of determination results of “◯” (four stages of 0 to 3) is larger. The light receiving element farthest from the light emitting element 130 among the light receiving elements from which the determination result of “◯” was obtained (represented by a double line in FIG. 10) represents the water quality in four stages. It can also be said. The light receiving element (represented by a triple line in FIG. 10) of the light receiving elements from which the determination result of “x” was obtained represents the water quality in four stages. It can also be said. The three distances may be experimentally determined in advance in the same manner as the light emission intensities LV1, LV2, and LV3 in the embodiment of FIG.

  FIG. 11 is a timing chart showing acquisition of water quality information. This chart shows a chart when the water quality sensor 300a (FIG. 9) is applied instead of the water quality sensor 300 in the waste water treatment apparatus 900 shown in FIG. In the embodiment of FIG. 11, the water quality sensor 300a acquires water quality information every hour. In one acquisition, the light emission control unit 210a causes the light emitting element 130 to emit light for a predetermined time (for example, 5 seconds) with a predetermined light emission intensity EI. The determination unit 220a acquires the light reception intensities RIa, RIb, and RIc of the light receiving elements 140a, 140b, and 140c in a state where the light emitting element 130 emits light, and performs three determinations regarding the three light reception intensities RIa, RIb, and RIc. Do. In the figure, the determination result is represented by either “◯” or “x”, which is the same as in FIG. In the example of FIG. 11, the water quality changes in the same manner as in the example of FIG. The data logger 400 (FIG. 6) records the determination result and the date and time, and displays the determination result according to the user's instruction, as in the above embodiments. Thereby, the user can confirm the water quality at the desired date and time easily. In this embodiment, since the water quality sensor 300a includes the three light receiving elements 140a, 140b, and 140c, the three determinations can be performed in parallel. In this way, the time required for determination can be shortened.

  As described above, the water quality sensor 300a of the present embodiment also outputs water quality information based on the three determination results in the same manner as the water quality sensor 300 described above. Therefore, this water quality sensor 300a also has various advantages similar to the water quality sensor 300 described above. Further, since it is not necessary to change the light emission intensity, the configuration of the light emission control unit 210a can be simplified. Further, the water quality sensor 300a may be applied to the wide area water quality management system 1100 shown in FIG. In this case as well, the same advantages as when the water quality sensor 300 is used can be obtained.

D. Fourth embodiment:
FIG. 12 is an explanatory view showing another embodiment of the water quality sensor. There are two differences from the water quality sensor 300a shown in FIG. The first difference is that three light emitting elements 130 a, 130 b and 130 c are provided on the first wall 122. The first light emitting element 130a is disposed at a position facing the first light receiving element 140a (first pair Pa), and the second light emitting element 130b is disposed at a position facing the second light receiving element 140b (second pair Pb). ), The third light emitting element 130c is arranged at a position facing the third light receiving element 140c (third pair Pc). Thus, the first light receiving element 140a mainly receives light from the first light emitting element 130a, and the second light receiving element 140b mainly receives light from the second light emitting element 130b, and receives the third light receiving element 140c. Mainly receives light from the third light emitting element 130c. In the present embodiment, the distance between the light emitting element and the light receiving element is the same in each of the three pairs Pa, Pb, and Pc. The second difference is that the light emission control unit 210b sets the light emission intensities EIa, EIb, EIc of the three light emitting elements 130a, 130b, 130c to different intensities (in the present embodiment, the first difference) Emission intensity EIa> second emission intensity EIb> third emission intensity EIc). As in the embodiment of FIG. 9, the determination unit 220a makes three determinations by comparing the light reception intensities RIa, RIb, RIc of the three light receiving elements 140a, 140b, 140c with a common threshold ( It can be said that the common threshold value is associated with each of the three light receiving elements 140a, 140b, and 140c in advance). The configuration of other elements of the water quality sensor 300b of the present embodiment is the same as the configuration of the elements having the same reference numerals of the water quality sensor 300a shown in FIG.

  In the present embodiment, the distance between the light emitting element and the light receiving element and the threshold value are common to the three pairs Pa, Pb, and Pc. Therefore, it can be said that the smaller the minimum emission intensity that can obtain the determination result that the threshold condition is satisfied, the better the water quality. Therefore, the water quality sensor 300b of the present embodiment can evaluate the water quality as in the table of FIG. As described above, the water quality sensor 300b according to the present embodiment outputs water quality information based on the three determination results, similarly to the water quality sensors 300 and 300a described above. Therefore, this water quality sensor 300b also has various advantages similar to the above-described water quality sensors 300 and 300a. In this embodiment, since the water quality sensor 300b has three pairs Pa, Pb, and Pc, three determinations can be performed in parallel. In this way, the time required for the determination can be shortened as compared with the case where the three determinations are sequentially performed one by one. Also in this embodiment, since the outline of the water quality is evaluated in four stages, the configuration of the water quality sensor 300b can be simplified. Further, the water quality sensor 300b may be applied to the wide area water quality management system 1100 shown in FIG. In this case as well, the same advantages as when the water quality sensor 300 is used can be obtained. The three light emission intensities EIa, EIb, and EIc may be experimentally determined in advance in the same manner as the light emission intensities LV1, LV2, and LV3 in the embodiment of FIG.

E. Example 5:
FIG. 13 is an explanatory view showing another embodiment of the water quality sensor. There are two differences from the water quality sensor 300b shown in FIG. The first difference is that the light emission control unit 210c sets the light emission intensities EIa, EIb, and EIc of the three light emitting elements 130a, 130b, and 130c to the same value. The second difference is that the determination unit 220c has a threshold setting unit 222c. The threshold value setting unit 222c sets the three threshold values Tha, Thb, and Thc respectively associated with the three received light intensities RIa, RIb, and RIc to different values (in this embodiment, the first threshold value Tha <second Threshold value Thb <third threshold value Thc). The determination unit 220c compares the first received light intensity RIa with the first threshold value Tha, compares the second received light intensity RIb with the second threshold value Thb, and compares the third received light intensity RIc with the third threshold value Thc. Make one decision. The configuration of other elements of the water quality sensor 300c is the same as the configuration of elements having the same reference numerals shown in FIG. In addition, as a structure of the threshold value setting part 222c, the various structure which sets the threshold value utilized by the determination part 220c is employable. For example, a circuit that outputs a reference voltage (corresponding to a threshold) used in the comparator circuit may be employed.

  FIG. 14 is a table showing the relationship between three determination results and water quality, similar to FIG. The meanings of the marks (“◯” and “x”) representing the determination result are the same as the meanings of the same marks in FIG. In the present embodiment, the distance between the light emitting element and the light receiving element and the light emission intensity are common to the three pairs Pa, Pb, and Pc. As a result, the three received light intensities RIa, RIb, and RIc have substantially the same value. Therefore, it can be said that the water quality is better as the maximum threshold at which the determination result of “◯” can be obtained is larger. As a result, as in the example of FIG. 10, the three determination results represent the water quality in four stages. Specifically, the water quality is better as the total number of determination results of “◯” (four stages of 0 to 3) is larger. It can also be said that the highest threshold (represented by a double line in FIG. 14) among the thresholds from which the determination result of “◯” is obtained represents the water quality in four stages. It can also be said that the lowest threshold (represented by a triple line in FIG. 14) among the thresholds from which the determination result of “x” is obtained represents the water quality in four stages. Note that the three threshold values Tha, Thb, and Thc may be experimentally determined in advance, similarly to the light emission intensities LV1, LV2, and LV3 in the embodiment of FIG.

  As described above, the water quality sensor 300c according to the present embodiment also outputs water quality information based on the three determination results in the same manner as the water quality sensor 300 described above. Therefore, the water quality sensor 300c also has various advantages similar to the water quality sensor 300 described above. In this embodiment, since the water quality sensor 300c has three pairs Pa, Pb, and Pc, three determinations can be made in parallel. In this way, the time required for the determination can be shortened as compared with the case where the three determinations are sequentially performed one by one. Further, the water quality sensor 300c may be applied to the wide area water quality management system 1100 shown in FIG. In this case as well, the same advantages as when the water quality sensor 300 is used can be obtained.

  Note that the threshold setting unit 222c shown in FIG. 13 may be applied to the water quality sensor 300a shown in FIG. In this case, it is preferable to increase the threshold value as the distance between the light emitting element and the light receiving element is longer. In this way, water quality that requires the minimum threshold value among the three threshold values (bad water quality) for establishment of the threshold condition, and water quality that satisfies the threshold condition sufficiently with the maximum threshold value among the three threshold values ( The difference in water quality can be increased. Thereby, the range of the water quality covered by three determinations can be expanded. When the threshold setting unit 222c shown in FIG. 13 is applied to the water quality sensor 300a shown in FIG. 9, the distance between the light emitting element 130 and the light receiving element is about each of the three light receiving elements 140a, 140b, 140c. It may be the same. Also in this case, water quality information can be acquired using three determination results with different threshold values. Further, the threshold setting unit 222c shown in FIG. 13 may be applied to the water quality sensor 300 shown in FIG. Here, the light emission control unit 210 may maintain the light emission intensity EI of the light emitting element 130 at a predetermined value without changing. Also in this case, the outline of the water quality can be evaluated using three determination results having different threshold values. In any case, various advantages similar to those of the water quality sensor 300 described above can be obtained.

F. Example 6:
FIG. 15 is an explanatory view showing another embodiment of the water quality sensor. The difference from the water quality sensor 300b shown in FIG. 12 is that the two light receiving elements 140b and 140c are omitted. In this embodiment, three determinations are made using light incident on the light receiving element 140a from the light emitting elements 130b and 130c in addition to the light emitting element 130a. Specifically, the light emission control unit 210b causes the three light emitting elements 130a, 130b, and 130c to emit light one by one in order, similarly to the light emission timing chart shown in FIG. Similar to the determination timing chart illustrated in FIG. 7, the determination unit 220 acquires the light reception intensity RIa of the light receiving element 140a in a state where the light emitting element emits light, thereby obtaining the three light emission intensities EIa, EIb, and EIc. Make a decision on each. The predetermined threshold used for the determination is common to the three determinations. The configuration of other elements of the water quality sensor 300d is the same as the configuration of the elements having the same reference numerals of the water quality sensors 300 and 300b shown in FIGS.

  In this embodiment, the stronger the light emission intensity, the stronger the light reception intensity RIa of the light receiving element 140a. Therefore, the water quality can be evaluated in the same manner as in the embodiment of FIG. Thus, the water quality sensor 300d of the present embodiment also has various advantages similar to the water quality sensor 300 described above. In this embodiment, among the three light emitting elements 130a, 130b, and 130c, the first light emitting element 130a is closest to the light receiving element 140a, and the third light emitting element 130c is farthest from the light receiving element 140a. The light emission control unit 210b sets the three light emission intensities EIa, EIb, and EIc so that the light emission intensity of the light emitting element decreases as the distance between the light emitting element and the light receiving element 140a increases. Therefore, the difference in the light reception intensity RIa with respect to the three light emission intensities EIa, EIb, and EIc can be increased. That is, the threshold condition is sufficiently satisfied with the water quality (bad water quality) that requires the maximum light emission intensity EIa among the three light emission intensities and the minimum light emission intensity EIc among the three light emission intensities. The difference in water quality between water quality (good water quality) can be increased. Thereby, the range of the water quality covered by three determinations can be expanded.

  In this embodiment, the three emission intensities EIa, EIb, and EIc may be the same. Also in this case, water quality information can be acquired using three determinations based on the difference in distance, as in the embodiment of FIG. In the present embodiment, the distance between the light emitting element and the light receiving element 140a may be the same for the three light emitting elements 130a, 130b, and 130c. In this case as well, water quality information can be acquired using three determinations based on the difference in emission intensity, as in the embodiment of FIG.

G. Seventh embodiment:
FIG. 16 is an explanatory view showing another embodiment of the water quality sensor. There are two differences from the water quality sensor 300c shown in FIG. The first difference is that the distance between the light emitting element and the light receiving element is different for each pair Pa, Pb, Pc (in this embodiment, the distance between the first pair Pa is the shortest, the third The distance of the pair Pc is the longest). The second difference is that the threshold setting unit 222c is omitted from the determination unit 220e. Similar to the determination unit 220a of FIG. 12, the determination unit 220e makes three determinations using the same threshold value common to the three received light intensities RIa, RIb, and RIc. Similarly to the light emission control unit 210c of FIG. 13, the light emission control unit 210e sets the light emission intensities EIa, EIb, and EIc of the three light emitting elements 130a, 130b, and 130c to the same value. If the water quality sensor 300e of this embodiment is used, the configuration of the water quality sensor 300e can be simplified as in the embodiments of FIGS. 9 and 10, and the three determinations based on the difference in distance can be used simply. Water quality information can be acquired.

  Note that the light emission control unit 210e of the present embodiment has the light emission intensities EIa and EIb so that the light emission intensity decreases as the distance between the light emitting element and the light receiving element increases as in the light emission control unit 210b of FIG. , EIc may be set. In this way, the water quality range covered by the three determinations can be expanded as in the embodiment of FIG. Further, the determination unit 220e of this embodiment may include a threshold setting unit 222c as in the embodiment of FIG. In this case, the threshold value setting unit 222c sets three threshold values for the three light receiving intensities RIa, RIb, and RIc so that the threshold value increases as the distance between the light emitting element and the light receiving element increases. It is preferable to set. In this way, the range of water quality covered by the three determinations can be expanded.

H. Variations:
In addition, elements other than the elements claimed in the independent claims among the constituent elements in each of the above embodiments are additional elements and can be omitted as appropriate. The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

Modification 1:
The multiple determinations used for acquiring water quality information are not limited to the determinations used in each of the above-described embodiments, but various determinations that are different from each other in water quality (worst water quality) necessary for establishment of the threshold condition are adopted. Is possible. The total number of such determinations is not limited to 3, and may be 2 or 4 or more (in general, N determinations (N is an integer of 2 or more) may be used). However, in order to easily obtain and use water quality information, the total number of determinations is preferably 10 or less, and particularly preferably 5 or less. Moreover, you may acquire water quality information using one determination. In this way, water quality information can be acquired more easily.

Modification 2:
In each of the above-described embodiments, the binary information representing the determination result is not limited to the information represented by the contact output, and various information can be employed. For example, a binary signal represented by a predetermined H level voltage and a predetermined L level voltage may be employed, or 1-bit digital data may be employed.

Modification 3:
The form of notifying the water quality information to the user is not limited to the form of displaying each of the N determination results as shown in FIG. 4, but adopts an arbitrary form of notifying the information indicating the water quality expressed in N + 1 stages. Is possible. For example, information representing one of N + 1 stages such as “good” and “normal” may be displayed. Further, the notification method is not limited to display, and various methods such as a method of transmitting to a user using sound or vibration can be employed.

Modification 4:
In each of the above-described embodiments, at least one of the notification unit 270 (FIG. 2), the data processing unit 410 (FIG. 6), and the data processing unit 1010 (FIG. 8) indicates that the water quality does not satisfy a predetermined standard. This may be notified to the user when the determination result to be expressed is obtained. For example, the data processing unit 410 may display the fact on the display device 430 when the determination result that the water quality is “bad” is obtained. In this way, the user can easily confirm the presence / absence of a defect in the water treatment tank 800 by observing the display device 430.

Modification 5:
The configuration of the sensor unit that holds the light emitting element and the light receiving element is not limited to the configuration of each of the embodiments described above, and various configurations can be employed. For example, in the embodiment shown in FIG. 1, the recess 120 may be provided in the central portion of the sensor unit 100. In the embodiments shown in FIGS. 12, 13, and 16, a light shielding plate may be disposed between the pair (for example, between the first pair Pa and the second pair Pb). Alternatively, the light emission (determination) may be performed sequentially for each pair, and the determination results for all pairs may be acquired. Alternatively, a light-emitting element with high directivity of emitted light may be employed. According to these configurations, it is possible to reduce the possibility that light from another pair of light emitting elements affects the determination result of one pair. Further, the shape of the recess is not limited to the shape of the recess 120 in FIG. 1 and the shape of the recess 120e in FIG. 16, and other shapes may be adopted. In general, as a configuration of the sensor unit, an arbitrary configuration in which a light emitting element and a light receiving element are arranged so as to sandwich a space into which water to be measured is introduced can be adopted.

Modification 6:
The configuration of the water quality sensor is not limited to the configurations of the above-described embodiments, and various configurations can be employed. For example, in the water quality sensor 300 shown in FIG. 2, part or all of the configuration of the control unit 200 may be provided in the sensor unit 100. 6 and 7, even if the binary information output unit 240 of the control unit 200 acquires the three determination results and then updates the three contact outputs at the same timing (same time). Good. In this case, the data logger 400 records three determination results at the same time. In addition to the signal from the sensor unit 100, the control unit 200 may process a signal from another device (for example, an alarm device for a blower). A plurality of sensor units may be connected to one control unit 200.

Modification 7:
In each of the above-described embodiments, the position of the sensor unit in the water treatment tank 800 (FIGS. 5 and 6) is not limited to the precipitation tank 816, and any position in the water treatment tank 800 can be employed. For example, the sensor unit 100 may be disposed in a flow path of water that flows from the anaerobic filter bed tank 812 to the contact aeration tank 814.

  Moreover, as a structure of the water treatment tank 800, not only the structure shown in FIG. 5 but the various structure which performs the purification process of waste_water | drain is employable. For example, instead of the contact aeration tank 814, a carrier fluidized biological filtration tank may be adopted. Further, a flow rate adjustment tank may be provided in the water treatment tank 800. Moreover, you may employ | adopt the water treatment tank which purifies waste_water | drain according to another processing system (for example, membrane separation system).

Modification 8:
In each of the above embodiments, a part of the configuration realized by hardware may be replaced with software, and conversely, part or all of the configuration realized by software may be replaced with hardware. Also good. For example, the water quality information output unit 230 in FIG. 2 may be configured using a computer that operates according to a predetermined program.

  In addition, when part or all of the functions of the present invention are realized by software, the software (computer program) can be provided in a form stored in a computer-readable recording medium. In the present invention, the “computer-readable recording medium” is not limited to a portable recording medium such as a flexible disk or a CD-ROM, but an internal storage device in a computer such as various RAMs and ROMs, a hard disk, and the like. An external storage device fixed to the computer is also included.

10 ... Water to be measured 12 ... Cable 100 ... Sensor unit 120, 120e ... Recessed portion 122 ... First wall 124 ... Second wall 130, 130a, 130b, 130c ... Light emission Element 140, 140a, 140b, 140c ... Light receiving element 200 ... Control unit 210, 210a, 210b, 210c, 210e ... Light emission control unit 220, 220a, 220c, 220e ... Determination unit 222c ... Threshold setting unit 230 ... Water quality information output unit 240 ... Binary information output unit 251 ... Switch 260 ... Terminal panel 261,262,263 ... Terminal pair 270 ... Notification unit 280 .. Display panel 281, 282, 283 ... Lamp 290 ... Operation panel 300, 300a, 300b, 300c, 300d, 300e ... Water quality sensor 400 ... Data logger 410 ... Data processing unit 420 .. Recording device 43 0 ... Display device 440 ... Operation panel 460 ... Terminal panel 461, 462, 463 ... Terminal pair 500 ... Communication terminal 600 ... Control terminal 800 ... Water treatment tank 802 .. Inlet 804 ... Outlet 810 ... Contaminant removal tank 812 ... Anaerobic filter bed tank 814 ... Contact aeration tank 816 ... Settling tank 816a ... Partition plate 818 ... Disinfection tank 818a ... Wall 900 ... Wastewater treatment device 1000 ... Management device 1010 ... Data processing unit 1020 ... Recording device 1030 ... Display device 1040 ... Operation panel 1050 ... Communication terminal 1100 ... Wide area water quality management system Pa, Pb, Pc ... Pair

Claims (7)

A water quality sensor that obtains water quality information, which is information about the quality of water to be measured,
A light emitting element that emits light and irradiates the measurement target water with light;
N light receiving elements (N is an integer of 2 or more and 5 or less) that receive the light from the light emitting element through the measurement target water and detect the light receiving intensity that is the intensity of the received light; ,
A determination unit configured to execute, for each of the N light receiving elements, a determination as to whether or not a threshold condition that the received light intensity is larger than a threshold value previously associated with the light receiving elements is satisfied;
Based on the N determination results obtained using the N light receiving elements, N binary information respectively representing the N determination results as the water quality information is represented by the N binary values. A binary information output unit for outputting to a data recording device for recording information;
With
The N light receiving elements are arranged such that a distance between the light emitting element and the light receiving element is different between the N light receiving elements.
Water quality sensor. The water quality sensor according to claim 1 , further comprising:
A threshold setting unit configured to set the threshold value of each of the N light receiving elements such that the threshold value increases as the distance between the light emitting element and the light receiving element increases.
Water quality sensor. The water quality sensor according to claim 1 or 2 ,
It is information determined based on the results of the N determinations, and includes a notification unit that notifies the user of the information indicating the water quality in the N + 1 stage as the water quality information.
Water quality sensor. Wastewater treatment equipment,
A water treatment unit for purifying wastewater;
The water quality sensor according to any one of claims 1 to 3 , wherein the light emitting element and the light receiving element are disposed in a portion of water that is a target of acquisition of water quality information in the water treatment unit. A water quality sensor,
A wastewater treatment apparatus comprising: A wastewater treatment system,
Wastewater treatment equipment of M groups (M is an integer of 2 or more) installed apart from each other;
A management device for managing each of the M wastewater treatment devices;
With
Each of the M wastewater treatment devices is
A water treatment unit for purifying the waste water;
The water quality sensor according to any one of claims 1 to 3 , wherein the light emitting element and the light receiving element are disposed in a portion of water that is a target of acquisition of water quality information in the water treatment unit. A water quality sensor,
A transmission unit for transmitting data representing the N pieces of binary information output by the binary information output unit to the management device;
With
The management device
A receiving unit for receiving data representing the N pieces of binary information transmitted by the transmitting unit of each of the M wastewater treatment devices;
A data processing unit for processing the received data;
Equipped with a wastewater treatment system. The wastewater treatment system according to claim 5 ,
The data processing unit is information determined based on the N pieces of binary information represented by the received data, and informs the user of the information indicating the water quality in the N + 1 stage.
Wastewater treatment system. The wastewater treatment system according to claim 5 or 6 ,
The management device further includes a recording unit for recording data,
The data processing unit records a history of the binary information represented by the received data in the recording unit;
Wastewater treatment system.