CN117413169A

CN117413169A - Water quality analysis device

Info

Publication number: CN117413169A
Application number: CN202280036948.5A
Authority: CN
Inventors: 篠田素美; 小泉和裕
Original assignee: Fuji Electric Co Ltd
Current assignee: Fuji Electric Co Ltd
Priority date: 2022-05-13
Filing date: 2022-05-13
Publication date: 2024-01-16
Also published as: KR20230172600A; WO2023218672A1; JPWO2023218672A1

Abstract

The present invention provides a water quality analysis device for measuring the concentration of a substance to be measured contained in sample water, comprising: a flow cell having a wall portion through which light passes and an internal space surrounded by the wall portion, the sample water passing through the internal space; a light source that irradiates light toward the flow cell; a light source monitor that detects a light source light amount, which is a light amount of the light irradiated by the light source; a transmitted light detection unit that detects a transmitted light amount, which is a light amount of transmitted light transmitted through the flow cell; and a dirt detecting section that detects dirt of the wall section of the flow cell based on the light source light amount and the transmitted light amount.

Description

Water quality analysis device

Technical Field

The present invention relates to a water quality analysis device.

Background

Conventionally, there is known a water quality analysis device that analyzes the quality of sample water (for example, refer to patent documents 1 and 2).

Patent document 1 japanese patent No. 6436266

Patent document 2 japanese patent laid-open publication No. 2006-194659

Disclosure of Invention

The invention aims to solve the technical problems

In the water quality analyzer, it is preferable that the fouling of the flow cell through which the sample water flows can be detected with high accuracy.

Disclosure of Invention

In order to solve the above-described problems, in embodiment 1 of the present invention, a water quality analyzer is provided for measuring the concentration of a substance to be measured contained in sample water. The water quality analysis device may include a flow cell having a wall portion through which light passes, and an inner space surrounded by the wall portion, through which the sample water passes. The water quality analysis device may include a light source that irradiates light to the flow cell. The water quality analyzer may include a light source monitor for detecting a light source light amount, which is a light amount of the light irradiated by the light source. The water quality analyzer may include a transmitted light detecting unit that detects a transmitted light amount, which is a light amount of transmitted light transmitted through the flow cell. The water quality analysis device may include a dirt detection unit that detects dirt on the wall of the flow cell based on the light source light amount and the transmitted light amount.

In any of the water quality analysis devices, the dirt detecting unit may detect dirt on the wall portion based on a ratio of the light source light amount to the transmitted light amount.

The water quality analysis device may include a cleaning portion that cleans dirt on the wall portion of the flow cell. In the above-described water quality analysis device, the dirt detecting unit may determine whether or not the washing of the flow cell is completed based on the light source light amount and the transmitted light amount detected after the washing of the flow cell.

In any of the above water quality analysis devices, the dirt detection unit may output a notification indicating that the cleaning has not been completed when the cleaning has not been completed within a set period from the start of the cleaning of the flow cell.

In the above-described water quality analysis device, the scale detection unit may change the cleaning method of the cleaning unit when the cleaning is not completed within a set period from the start of the cleaning of the flow cell.

In the above-described water quality analyzer, the washing unit may select a washing method of the flow cell based on at least one of the light source light amount and the transmitted light amount.

In any of the above water quality analysis devices, the washing unit may adjust a pH value of the washing liquid flowing through the flow cell based on a ratio of the light source light amount to the transmitted light amount.

In the above-described water quality analysis device, the washing unit may select a washing method of the flow cell based on a history of the sample water flowing through the flow cell in the past.

In the above water quality analysis device, the dirt detecting unit may detect dirt on the wall portion using the transmitted light amount in a state where the sample water is not allowed to flow through the flow cell.

In the above water quality analysis device, the dirt detecting unit may detect dirt on the wall portion using the transmitted light amount in a state where the sample water is caused to flow through the flow cell.

The water quality analysis device may include a scattered light detection unit that detects a scattered light amount, which is a light amount of scattered light from the sample water. In the above water quality analysis device, the dirt detection unit may detect dirt on the wall of the flow cell based on the amount of scattered light.

The water quality analyzer may further include a turbidity measuring unit that measures turbidity of the sample water based on at least one of the amount of scattered light detected by the scattered light detecting unit and the amount of transmitted light detected by the transmitted light detecting unit.

The summary of the invention does not set forth all features of the invention. In addition, sub-combinations of these feature sets may also constitute the invention.

Drawings

Fig. 1 is a diagram showing an example of a water quality analysis device 100 according to an embodiment of the present invention.

Fig. 2 is a diagram showing an example of the light source light quantity, the transmitted light quantity, and the light quantity ratio (transmitted light quantity/light source light quantity).

Fig. 3 is a flowchart showing an example of the operation of the water quality analyzer 100.

Fig. 4 is a flowchart showing another example of the operation of the water quality analyzer 100.

Fig. 5 is a flowchart showing another example of the operation of the water quality analyzer 100.

Fig. 6 is a diagram showing a configuration example of the measurement light detection unit 30 and the concentration measurement unit 32.

Detailed Description

The present invention will be described below by way of embodiments of the invention, but the following embodiments are not intended to limit the invention as claimed. In addition, all combinations of the features described in the embodiments are not necessarily required as a technical means for solving the technical problems of the present invention.

Fig. 1 is a diagram showing an example of a water quality analysis device 100 according to an embodiment of the present invention. The water quality analysis device 100 measures the concentration of a substance to be measured contained in sample water. The water quality analyzer 100 of this example includes a light source 10, a flow cell 20, a light source monitor 50, a measurement light detection unit 30, a concentration measurement unit 32, a transmission light detection unit 70, a dirt detection unit 40, and a washing unit 60. The light source monitor 50, the measurement light detection unit 30, and the transmission light detection unit 70 are devices that detect the amount of received light using a light receiving element such as a CCD or a photodiode. In the present specification, the light quantity refers to the total quantity (lm/S) of light beams passing through a prescribed surface in a prescribed unit time, but the intensity (cd) of light may be used as the light quantity. The light source monitor 50, the measurement light detection unit 30, and the transmission light detection unit 70 output an electric signal corresponding to the detected light amount. The light source monitor 50, the measurement light detection unit 30, and the transmission light detection unit 70 perform signal processing such as amplification and noise removal on the electric signal.

The light source 10 irradiates light 91 towards the flow cell 20. The flow cell 20 has a wall 22 and an interior space 24. At least a part of the wall 22 is formed of a material that transmits at least a part of the component of the light 91 irradiated by the light source 10. At least a portion of the wall portion 22 is formed of glass, for example. The wall portion 22 may have a window portion into which light is incident or emitted and a support portion that supports the window portion. In this specification, the window portion into which light is incident or emitted is sometimes described as a wall portion 22. The interior space 24 is surrounded by the wall portion 22. Sample water passes through the interior space 24. As an example, the wall portion 22 has a cylindrical shape. Fig. 1 schematically shows a cross section of a wall portion 22 and an inner space 24.

The measurement light detection unit 30 detects the measurement light 92 from the flow cell 20. The measurement light detection unit 30 measures the amount of light at least one wavelength of the measurement light 92. The measurement light 92 is light emitted from the flow cell 20 when the light 91 is irradiated from the light source 10 in a state where the sample water is present in the flow cell 20. The measurement light 92 may include fluorescence emitted from a measurement target substance included in the sample water by irradiation of the light 91 with the measurement target substance. In this case, the measurement light detection unit 30 can measure the light quantity of the measurement light 92 at a wavelength different from that of the light 91.

The concentration measuring unit 32 measures the concentration of the substance to be measured contained in the sample water based on the measurement result in the measurement light detecting unit 30. The sample water is, for example, tap water, sewer water, seawater, factory wastewater, or the like, but is not limited thereto. When a fluorescent substance such as polycyclic aromatic hydrocarbon (Polycyclic Aromatic Hydrocarbons: hereinafter referred to as PAH) is contained in the sample water, if ultraviolet light 91 is irradiated to the sample water, fluorescence (measurement light 92) having a wavelength specific to the substance is generated. Since the fluorescence intensity is proportional to the concentration of the fluorescent substance contained, the concentration of the fluorescent substance as the measurement target substance can be measured with high accuracy by measuring the light quantity of the measurement light 92 at the wavelength.

If dirt is generated on the wall 22 of the flow cell 20, the intensity of the light 91 or the measuring light 92 is attenuated by the dirt. In the case where the wall 22 is provided with the window, dirt on the wall 22 refers to dirt on the window. Dirt of the wall portion 22 refers to, for example, foreign matter adhering to the inner surface or the outer surface of the wall portion 22. If the intensity of the light 91 or the measurement light 92 is attenuated, an error occurs in the measurement result of the concentration of the measurement target substance. Therefore, it is preferable to be able to detect with high accuracy whether or not dirt is generated on the wall 22 of the flow cell 20.

The dirt detecting unit 40 detects dirt in the wall 22. The dirt detecting unit 40 may detect dirt on the wall 22 by triggering a predetermined operation in the water quality analysis device 100. For example, when the wall 22 of the flow cell 20 is cleaned by the cleaning unit 60, the dirt detecting unit 40 detects dirt on the cleaned wall 22. The cleaning portion 60 may clean the inner surface of the wall portion 22 by flowing cleaning liquid into the inner space 24 of the flow cell 20, or may clean the wall portion 22 by bringing a brush or the like into contact with the inner surface or the outer surface of the wall portion 22. The cleaning portion 60 may clean the wall portion 22 each time a set cleaning period passes. When the degree of dirt in the wall 22 is out of the allowable range, the dirt detecting unit 40 may notify the cleaning unit 60 that the cleaning is not completed. Upon receiving the notification, the cleaning portion 60 may clean the wall portion 22 of the flow cell 20 again.

The dirt detecting portion 40 can detect dirt of the wall portion 22 every time the set detection period elapses. The dirt detecting unit 40 may detect dirt on the wall 22 at predetermined detection intervals, and cause the cleaning unit 60 to clean the wall 22 when the degree of dirt on the wall 22 is out of the allowable range. The dirt detecting unit 40 may detect dirt on the wall 22 according to an instruction of a user or the like. In this case, the dirt detecting unit 40 may cause the cleaning unit 60 to clean the wall 22 when the dirt level of the wall 22 is outside the allowable range.

When the dirt detecting unit 40 detects dirt on the wall 22, the light source 10 irradiates the flow cell 20 with light 91 having a predetermined wavelength component. The wavelength of the light 91 at the time of detecting the dirt may be different from the wavelength of the light 91 at the time of measuring fluorescence of the object substance. The light source 10 may have a light source unit that irradiates light 91 for detecting dirt, and a light source unit that irradiates light 91 for detecting fluorescence.

The transmitted light detection unit 70 irradiates light 91 into the flow cell 20 and detects transmitted light 94 transmitted through the flow cell 20. For example, the transmitted light detection light section 70 may detect light that the light 91 travels straight inside the flow cell 20 and emits as transmitted light 94. The wall 22 may be provided with a window into which the light 91 is incident, a window from which the measurement light 92 is emitted, and a window from which the transmitted light is emitted. The transmitted light detecting section 70 detects the transmitted light amount, which is the light amount of the transmitted light 94. The transmitted light detection unit 70 can detect the transmitted light amount of the set wavelength. The transmitted light detecting section 70 outputs an electric signal indicating the amount of transmitted light to the dirt detecting section 40.

If dirt adheres to the wall portion 22, the intensity of light is attenuated by the dirt, and thus the transmitted light quantity of the transmitted light 94 becomes small. Therefore, by detecting to what extent the transmitted light quantity of the transmitted light 94 is attenuated with respect to the light quantity of the light 91 emitted from the light source 10, the degree of fouling of the wall portion 22 can be estimated. On the other hand, due to degradation of the light source 10 or the like, the light quantity of the light 91 emitted from the light source 10 may vary with time even if the setting value for the light source 10 is the same. If the amount of light 91 changes, this will result in a change in the amount of transmitted light 94. Therefore, it is difficult to detect the dirt of the wall portion 22 with high accuracy only from the transmitted light 94.

The water quality analyzer 100 of this example detects the light source light quantity, which is the light quantity of the light 91 irradiated by the light source 10, by the light source monitor 50. The light source monitor 50 detects the light source quantity of the light 91 before entering the flow cell 20. The light source monitor 50 can receive the branched light 93 obtained by branching a part of the light 91.

The fouling detection section 40 detects fouling of the wall section 22 of the flow cell 20 based on the light source light amount and the transmitted light amount. The dirt detecting section 40 corrects the transmitted light amount with the light source light amount, and detects dirt of the wall section 22 based on the correction result. For example, the dirt detecting section 40 corrects to be larger as the light source light amount is smaller and the transmitted light amount is larger, and determines that the dirt degree of the wall section 22 is larger as the corrected transmitted light amount is smaller. As an example, the dirt detecting section 40 detects dirt of the wall section 22 based on a light amount ratio (transmitted light amount/light source light amount) of the light source light amount to the transmitted light amount. The dirt detecting unit 40 determines that the degree of dirt is greater as the light quantity ratio is smaller. As described above, by detecting fouling of the wall portion 22 using the light source light amount and the transmitted light amount, the influence of degradation or the like of the light source 10 can be reduced, and fouling of the wall portion 22 can be detected with high accuracy. The light source light amount and the transmitted light amount can be measured without flowing the sample water into the flow cell 20.

Fig. 2 is a diagram showing an example of the light source light quantity, the transmitted light quantity, and the light quantity ratio (transmitted light quantity/light source light quantity). The vertical axis in fig. 2 represents the light amount or the light amount ratio. Fig. 2 shows the light source light quantity, the transmitted light quantity, and the light quantity ratio in the plurality of states A, B, C, D. As an example, the state a is a state at factory shipment, and is a state in which the wall portion 22 is free from dirt and the light source 10 is not degraded. The state B is a state in which dirt is present on the wall portion 22 and the light source 10 is not degraded. The state C is a state in which no dirt is present on the wall portion 22, and the light source 10 is degraded. The state D is a state in which dirt is present on the wall portion 22 and the light source 10 is deteriorated. The degree of fouling of the wall 22 in the state B, D is the same, and the degree of degradation of the light source 10 in the state C, D is the same.

In fig. 2, a determination criterion in the case where the presence or absence of fouling of the wall portion 22 is detected based on only the transmitted light amount and a determination criterion in the case where the presence or absence of fouling of the wall portion 22 is detected based on the light amount ratio (transmitted light amount/light source light amount) are indicated by broken lines. The criterion is set in advance by a user or the like. For example, it is determined that "no dirt" is present when the light amount or the light amount ratio is greater than the determination reference, and it is determined that "dirt" is present when the light amount or the light amount ratio is less than the determination reference.

When the fouling of the wall portion 22 is detected based on the transmitted light amount alone, although the fouling of the state B, D can be detected, the fouling may be erroneously detected as "fouling" even in the state C where the wall portion 22 is not fouled. If only the transmitted light amount is used, the case where the transmitted light amount is attenuated by the degradation of the light source 10 and the case where the transmitted light amount is attenuated by the fouling of the wall portion 22 cannot be distinguished, and therefore the fouling of the wall portion 22 is erroneously detected in the case where the light source 10 is degraded. In addition, as in the state B, D, although the degree of fouling of the wall portion 22 is originally the same, the degree of fouling is detected differently due to degradation of the light source 10.

On the other hand, by using the light amount ratio (transmitted light amount/light source light amount), the influence of degradation of the light source 10 can be reduced. For example, as in the state C, the influence of the deterioration of the light source 10 is corrected, and the fouling of the wall 22 can be detected with high accuracy. The dirt detecting unit 40 can detect the presence or absence of dirt in the wall 22 by comparing the light quantity ratio with a dirt determination criterion. The scale detection unit 40 may determine the scale level based on the magnitude of the deviation of the light quantity ratio from the scale determination reference.

Fig. 3 is a flowchart showing an example of the operation of the water quality analyzer 100. The water quality analysis device 100 starts measuring the concentration of the substance to be measured in the sample water based on the predetermined trigger signal. The trigger signal may be input by a user or the like, may be automatically input by a change in the surrounding environment, may be automatically input every time a predetermined period elapses, or may be input by another factor.

In the measurement step S202, the concentration measurement unit 32 measures the sample water. The concentration measuring unit 32 measures the concentration of the substance to be measured based on the measuring light 92 measured by the measuring light detecting unit 30. As described above, the measurement light 92 may be fluorescence emitted from the sample water. At this time, the concentration measuring unit 32 can measure the concentration of the fluorescent substance based on the light amount of the measuring light 92.

In the continuous use stage S204, the water quality analysis device 100 continuously or intermittently measures the concentration of the substance to be measured in the sample water during a preset continuous use period. When the continuous use period has elapsed, in the cleaning stage S206, the cleaning portion 60 performs cleaning in the flow cell 20. The washing unit 60 may wash the flow cell 20 by flowing a washing liquid containing clean water, a medicine, or the like through the inner space 24 of the flow cell 20, may wash the flow cell 20 by sweeping a brush or the like across the inner space 24, and may wash the flow cell 20 by combining these.

After the cleaning unit 60 performs the predetermined cleaning process, the dirt detecting unit 40 determines whether or not the cleaning of the flow cell 20 is completed in the cleaning completion determination step S208. The dirt detecting unit 40 may detect the presence or absence of dirt in the wall 22 of the flow cell 20, and determine that the cleaning is completed when it is determined that there is no dirt. As shown in fig. 2, the dirt detecting unit 40 can determine whether dirt is present or not by comparing the light quantity ratio (transmitted light quantity/light source light quantity) with a predetermined dirt determination criterion. In the washing completion determination step S208, the transmitted light amount and the light source light amount may be measured in a state where the internal space 24 of the flow cell 20 is filled with clear water, or the transmitted light amount and the light source light amount may be measured in a state where the internal space 24 is not filled with liquid.

When it is determined in the cleaning completion determination step S208 that the cleaning is completed, the water quality analysis device 100 may repeat the processing from the measurement step S202 or may end the operation. When it is determined in the cleaning completion determination step S208 that the cleaning is not completed, the cleaning unit 60 repeats the process of the cleaning step S206. When the cleaning of the flow cell 20 is not completed within the set period from the start of the cleaning, the dirt detection unit 40 may output a notification indicating that the cleaning is not completed. At this time, the water quality analysis device 100 may repeat the processing from the measurement stage S202, or may end the operation.

In the cleaning step S206, the cleaning unit 60 may select a method of cleaning the flow cell 20 based on at least one of the light source light amount and the transmitted light amount. The selection of the cleaning method may be a selection of the characteristics of the cleaning liquid used for cleaning, or a selection of the tool used for cleaning (whether a brush or a cleaning liquid is used, etc.). The cleaning section 60 may select the cleaning method according to the degree of dirt determined by the light quantity ratio (light source light quantity and transmitted light quantity). At this time, in the cleaning stage S206, the light quantity ratio can be measured. The cleaning section 60 can adjust the pH of the cleaning liquid flowing through the flow cell 20 according to the degree of dirt. The greater the degree of fouling, the greater the deviation of the pH of the cleaning solution from neutral. The degree of change in the pH value according to the degree of dirt may be experimentally determined in advance and set in the cleaning unit 60.

The washing unit 60 may select a washing method based on the history of the sample water flowing through the flow cell 20 in the past. In this example, the washing unit 60 may select a washing method according to the type of sample water flowing through the continuous use stage S204. The kind of the sample water may be a kind of a substance contained in the sample water. For example, any one of the acidic and alkaline cleaning liquids may be selectively used according to the kind of the sample water. Since the substance of the dirt adhering to the flow cell 20 can be estimated from the type of the sample water, the cleaning section 60 can select the cleaning liquid corresponding to the type of the sample water. What cleaning liquid should be selected for each substance may be set in the cleaning section 60 in advance. In the water quality analyzer 100 of this example, the portion where the cleaning liquid flows is preferably formed of a material that does not deteriorate even if the acidic or alkaline cleaning liquid flows.

The cleaning unit 60 may estimate the type of the substance adhering to the wall 22 based on the light quantity ratios (light source light quantity and transmitted light quantity) at the plurality of wavelengths, and select the cleaning method based on the estimation result. The cleaning unit 60 can estimate the type of the substance adhering to the wall 22 by comparing the shape of the spectrum of the light quantity ratio with the transmission spectrum determined according to the type of each substance. By using the light quantity ratio in which the deterioration of the light source 10 is corrected, the type of the substance adhering to the wall portion 22 can be estimated with high accuracy.

Fig. 4 is a flowchart showing another example of the operation of the water quality analyzer 100. The operation of this example differs from the operation example of fig. 3 in that the method further includes a period passing determination stage S210 and a cleaning method change stage S212. The other phases are the same as the example of fig. 3.

In this example, when it is determined in the cleaning completion determination stage S208 that cleaning is not completed, the progress period passes through the determination stage S210. In the period elapsed determination step S210, the dirt detection section 40 determines whether or not a set period has elapsed from the start of cleaning of the flow cell 20. When the set period has not elapsed, the dirt detecting unit 40 causes the cleaning unit 60 to repeat the process of the cleaning stage S206. When the cleaning is not completed within the set period, the dirt detecting unit 40 changes the cleaning method of the cleaning unit 60 in the cleaning method changing stage S212. When the cleaning unit 60 does not end the cleaning within the set period, a more powerful cleaning method can be selected. For example, when clean water is used but cleaning is not completed within a set period, the cleaning unit 60 may perform cleaning again using a chemical or a surfactant-containing cleaning liquid. In addition, the cleaning unit 60 may adjust the pH of the cleaning liquid when the cleaning liquid is used but the cleaning is not completed within the set period.

Fig. 5 is a flowchart showing another example of the operation of the water quality analyzer 100. The operation of this example differs from the operation example of fig. 3 or 4 in that the scale detection stage S205 is further provided. The other phases are the same as the examples of fig. 3 or fig. 4. Although fig. 5 shows an example in which the dirt detection stage S205 is added to the operation example of fig. 3, the dirt detection stage S205 may be added to the operation example of fig. 4.

The fouling detection section 40 of this example detects fouling of the wall section 22 using the transmitted light amount in a state where the sample water flows through the flow cell 20. Specifically, the fouling of the wall portion 22 is detected using the light source light amount and the transmitted light amount measured during the continuous use period in the continuous use stage S204. The dirt detecting portion 40 may detect dirt of the wall portion 22 at a predetermined cycle during continuous use. In the example of fig. 5, in the dirt detection stage S205 during continuous use, dirt of the wall portion 22 is detected. When it is determined in the dirt detection step S205 that the wall portion 22 is free of dirt, the water quality analysis device 100 continues the process of the continuous use step S204. When it is determined in the dirt detection stage S205 that the wall 22 is dirty, the water quality analysis device 100 performs the process after the cleaning stage S206. The processing after the cleaning stage S206 is the same as the example of fig. 3 or 4.

Fig. 6 is a diagram showing a configuration example of the measurement light detection unit 30 and the concentration measurement unit 32. The measuring light detecting section 30 of this example includes a fluorescence detecting section 33 and a scattered light detecting section 31. The concentration measuring unit 32 includes a signal processing unit 35 and a turbidity measuring unit 34. The water quality analyzer 100 of this example includes a light source 10-1 and a light source 10-2. The light source 10-1 is a light source that irradiates light 91-1 for measuring scattered light (measuring light 92-1), and the light source 10-2 is a light source that irradiates light 91-2 for measuring fluorescence (measuring light 92-2). The light 91-1 and the light 91-2 may have different wavelength components. Light 91-1 from light source 10-1 is also used for measurement of transmitted light 94. That is, a part of the light 91-1 is emitted as scattered light, and the other part is emitted as transmitted light.

The water quality analyzer 100 of this example measures the concentration of the fluorescent substance contained in the sample water based on the amount of fluorescence (measurement light 92-2). On the other hand, when suspended matter is contained in the sample water, the light quantity of the light 91-2 or the measuring light 92-2 may be attenuated due to the influence of light scattering and absorption from suspended matter (particles). This phenomenon is called the internal filtering effect. Due to the internal filter effect, in an environment where the concentration of suspended matter (hereinafter referred to as turbidity) is high, the measurement accuracy of the fluorescence intensity may deteriorate.

In order to improve the measurement accuracy of the fluorescence intensity, the water quality analyzer 100 of this example corrects the light quantity of the measurement light 92-2 measured based on the turbidity of the sample water. The water quality analysis device 100 measures fluorescence intensity together with turbidity of sample water. The water quality analyzer 100 measures turbidity of the sample water based on the amount of scattered light or transmitted light from the sample water 3. The scattered light detecting section 31 detects the amount of scattered light of the sample water. The transmitted light detecting section 70 shown in fig. 1 can detect the light amount of the transmitted light of the sample water.

First, measurement of turbidity of sample water will be described. The light source 10-1 irradiates light 91-1 as infrared light into the sample water inside the flow cell 20. The light source 10-1 is exemplified by an LED (Light Emitting Diode: light emitting diode) or a laser irradiation device.

Scattered light (measurement light 92-1) or transmitted light 94 (see fig. 1) is generated by irradiating light 91-1 into the sample water inside the flow cell 20. Scattered light is generated by light scattering of suspended matter contained in the sample water. The higher the concentration of the suspended matter, the more the amount of scattered light increases. The transmitted light 94 is light that is not absorbed or scattered by the suspension of the sample water 3. The higher the concentration of the suspended matter, the more attenuated the amount of transmitted light 94.

The turbidity measuring unit 34 can measure the turbidity of the sample water based on at least one of the amount of the measurement light 92-1 detected by the scattered light detecting unit 31 and the amount of the transmitted light 94 detected by the transmitted light detecting unit 70. The turbidity measuring unit 34 can measure turbidity from the amount of one of the measurement light 92-1 and the transmitted light 94. As described above, the amounts of the measurement light 92-1 and the transmitted light 94 vary according to the turbidity, and therefore the turbidity can be estimated from these amounts of light. The turbidity measuring unit 34 may calculate turbidity using the ratio of the amounts of the measurement light 92-1 and the transmitted light 94 (the amount of the measurement light 92-1/the amount of the transmitted light 94). The higher the turbidity, the greater the ratio of the amounts of light.

Next, measurement of the concentration of the fluorescent substance in the sample water will be described. Light source 10-2 irradiates light 91-2 into the sample water inside flow cell 20. As an example, light 91-2 is ultraviolet. As an example, the light source 10-2 is a xenon flash lamp, an LED, or a laser irradiation device.

The light source 10-2 may include an optical filter inside thereof. Since it includes an optical filter, the light source 10-2 can irradiate light within a prescribed wavelength range of the light 91-2 to the flow cell 2. In this example, the measurement target substance is PAH. PAH emits fluorescence most efficiently around 250nm in wavelength of excitation light. Therefore, as an example, the transmission wavelength of the optical filter of the light source 10-2 is set to 200nm or more and 300nm or less.

Fluorescence (measurement light 92-2) is generated by irradiating light 91-2 into the sample water inside the flow cell 20. The fluorescence detection section 33 detects the light amount of the measurement light 92-2. The fluorescence detection section 33 may include an optical filter therein. Since the optical filter is included, the fluorescence detection unit 33 can receive light within a predetermined wavelength range of the measurement light 92-2. In this example, the measurement target substance is PAH. Regarding PAH, when the wavelength of excitation light is around 250nm, the fluorescence wavelength is around 350 nm. Therefore, as an example, the transmission wavelength of the optical filter inside the fluorescence detection section 33 is set to 300nm or more and 400nm or less.

The signal processing unit 35 calculates the concentration of the fluorescent substance contained in the sample water based on the amount of the measurement light 92-2 detected by the fluorescence detecting unit 33. As described above, the light quantity of the measurement light 92-2 is attenuated by the turbidity of the sample water. The signal processing unit 35 corrects the light quantity of the measurement light 92-2 based on the turbidity measured by the turbidity measuring unit 34, and calculates the concentration of the fluorescent substance. The relationship between the turbidity and the correction amount may be experimentally determined in advance and set in the signal processing section 35. By such processing, the water quality analysis device 100 can accurately measure the concentration of the fluorescent substance in the sample water.

As described in fig. 5, when the fouling of the wall 22 is detected using the transmitted light amount in the state where the sample water flows through the flow cell 20, the transmitted light amount may be attenuated according to the turbidity of the sample water. At this time, the detection accuracy of the dirt of the wall portion 22 may be deteriorated.

The fouling detection section 40 may detect fouling of the wall section 22 of the flow cell 20 using the light quantity of scattered light (scattered light quantity) detected by the scattered light detection section 31, in addition to the transmitted light quantity and the light source light quantity. The dirt detecting unit 40 may use a transmitted light amount common to the turbidity measurement. Instead of the amount of scattered light, the turbidity calculated by the turbidity measuring unit 34 may be used by the dirt detecting unit 40. The dirt detecting section 40 may correct the transmitted light amount using the scattered light amount. That is, when the amount of scattered light is large, it is considered that the amount of transmitted light is greatly attenuated by suspended matter, so that the larger the amount of scattered light is, the larger the amount of transmitted light can be corrected. This reduces the influence of turbidity of the sample water, and can detect fouling of the wall 22 with high accuracy.

In another example, the dirt detecting unit 40 may determine dirt on the wall 22 on the condition that the amount of scattered light or turbidity is equal to or less than a reference value. That is, the fouling detection section 40 may perform fouling determination of the wall section 22 on the condition that the attenuation of the transmitted light amount of the sample water is small. This reduces the influence of turbidity of the sample water, and can detect fouling of the wall 22 with high accuracy.

In the example of fig. 6, the transmitted light amount for turbidity measurement and the transmitted light amount for fouling measurement can be detected by the common transmitted light detection section 70. The light source 10 for turbidity measurement and the light source 10 for fouling estimation can be used in common. Therefore, the number of structural members of the water quality analyzer 100 can be reduced.

The present invention has been described above using the embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various changes or modifications may be made to the above embodiments. It is apparent from the description of the claims that various modifications and improvements are also included in the technical scope of the present invention.

Note that the order of execution of the respective processes such as the operations, steps, procedures, and stages in the apparatus, system, program, and method shown in the claims, the specification, and the drawings may be implemented in any order unless explicitly indicated as "before", "before". Or the like, or the output of the previous process is used in the subsequent process. For convenience of description, the "first", "then" and the like are used with respect to the flow of actions in the claims, the specification and the drawings, but do not necessarily mean that the operations are performed in such order.

Description of the reference numerals

10..A.A light source, 20..A flow cell, 22..A wall portion, 24..A space inside, 30..A light detection portion, 31..A scattered light detection portion, 32..A concentration detection portion, 33..A fluorescence detection portion, 34..A turbidity detection portion, 35..A signal processing portion, 40..A dirt detection portion, 50..A light source monitor, 60..A cleaning portion, 70..A transmitted light detection portion, 91..A light, 92..A measuring light, 93..A branched light, 94..A transmitted light, 100..A water quality analysis device.

Claim (modification according to treaty 19)

1. A water quality analyzer for measuring the concentration of a substance to be measured contained in sample water, comprising:

a flow cell having a wall portion through which light passes and an internal space surrounded by the wall portion, the sample water passing through the internal space;

a light source that irradiates light toward the flow cell;

a light source monitor that detects a light source light amount, which is a light amount of the light irradiated by the light source;

a transmitted light detection unit that detects a transmitted light amount, which is a light amount of transmitted light transmitted through the flow cell; and

and a dirt detecting section that detects dirt on the wall section of the flow cell based on the light source light amount and the transmitted light amount.

2. The water quality analysis device according to claim 1, wherein,

the dirt detecting section detects dirt of the wall section based on a ratio of the light source light amount and the transmitted light amount.

3. The water quality analysis device according to claim 1, wherein,

further comprising a cleaning part for cleaning dirt on the wall part of the flow cell,

the dirt detecting unit determines whether or not the cleaning of the flow cell is completed based on the light source light amount and the transmitted light amount detected after the cleaning of the flow cell.

4. A water quality analyzing apparatus according to claim 3, wherein,

the dirt detecting unit outputs a notification indicating that the cleaning has not been completed when the cleaning has not been completed within a set period from the start of the cleaning of the flow cell.

5. A water quality analyzing apparatus according to claim 3, wherein,

the dirt detecting unit changes a cleaning method in the cleaning unit when cleaning is not completed within a set period from the start of cleaning of the flow cell.

6. A water quality analyzing apparatus according to claim 3, wherein,

the cleaning unit selects a method of cleaning the flow cell based on at least one of the light source light amount and the transmitted light amount.

7. The water quality analysis device according to claim 6, wherein,

the washing section adjusts a pH value of the washing liquid flowing through the flow cell based on a ratio of the light source light amount and the transmitted light amount.

8. A water quality analyzing apparatus according to claim 3, wherein,

the washing unit selects a washing method for the flow cell based on a history of the sample water flowing through the flow cell in the past.

9. A water quality analysis device according to any one of claim 1 to 8,

the fouling detection section detects fouling of the wall section using the transmitted light amount in a state where the sample water is not caused to flow through the flow cell.

10. A water quality analysis device according to any one of claim 1 to 8,

the fouling detection section detects fouling of the wall section using the transmitted light amount in a state where the sample water is caused to flow through the flow cell.

11. The water quality analysis device according to claim 10, wherein,

and a scattered light detecting unit for detecting a scattered light amount which is a light amount of scattered light from the sample water,

the dirt detecting section also detects dirt of the wall section of the flow cell based on the amount of scattered light.

12. The water quality analysis device according to claim 11, wherein,

the apparatus further includes a turbidity measuring unit that measures turbidity of the sample water based on at least one of the amount of scattered light detected by the scattered light detecting unit and the amount of transmitted light detected by the transmitted light detecting unit.

13. The water quality analyzer according to claim 1,

and a cleaning part for cleaning dirt on the wall of the flow cell,

the fouling detection section detects fouling of the wall section using the transmitted light amount in a state where the sample water is caused to flow through the flow cell,

the cleaning section starts cleaning the flow cell in the case where the wall portion is stained.

14. The water quality analyzer according to claim 13,

the fouling detection unit further includes a scattered light detection unit that detects a scattered light amount, which is a light amount of scattered light from the sample water, and detects fouling of the wall portion of the flow cell on the condition that the scattered light amount detected by the scattered light detection unit or turbidity of the sample water is equal to or less than a reference value, wherein the turbidity of the sample water is measured based on at least one of the scattered light amount detected by the scattered light detection unit and the transmitted light amount detected by the transmitted light detection unit.

Claims