JP7350621B2 - Turbidity measuring device, turbidity measuring method, water purification monitoring system - Google Patents

Description

The present invention relates to a turbidity measuring device and method using light scattering, and particularly to a turbidity measuring device and method used for water quality management.

Conventionally, turbidity, which indicates the degree of turbidity of water, has been used as an index for water quality management. For example, in the water supply industry, the turbidity at the outlet of filtration ponds, etc. is set at 0.1 degrees according to the "Guidelines for countermeasures against cryptosporidium, etc. in water supplies," which was applied to promote countermeasures against chlorine-resistant pathogenic organisms such as Cryptosporidium. If this level is exceeded, large-scale measures must be taken, such as stopping water intake. Therefore, monitoring and appropriately managing turbidity has become a very important issue.

Turbidity is measured using various methods such as transmitted light scattering method, surface scattering light method, transmitted light method, scattered light method, integrating sphere method, and particle counting method. It utilizes the transmission and scattering of light. For example, an apparatus is known that measures turbidity based on the number concentration and light scattering cross section of each particle size category of microparticles present in sample water using a microparticle counting method (see Patent Document 1).

By the way, various disorders occurring in water treatment processes include biological disorders caused by living organisms. For example, in the case of water treatment, problems such as filtration leakage, abnormal odor and taste, poor flocculation, and filtration blockage are generally recognized as biological problems. In order to prevent such biological damage, it is important to understand not only the turbidity but also the status of biological particles contained in water.

Patent No. 3672158

“Guidelines for measures against Cryptosporidium etc. in water supply”, Ministry of Health, Labor and Welfare, March 2007

According to the above-mentioned prior art, it is possible to measure the turbidity of sample water in real time, but even if the turbidity increases, it is difficult to determine whether the cause is biological. I can't. Therefore, in the water treatment process, apart from measuring turbidity, microorganisms are usually detected using a fluorescence microscope or culture.

However, with such a method, it is not possible to detect microorganisms in real time, so it is difficult to provide prompt and appropriate feedback in response to changes in turbidity. In addition, there is a known method of measuring the number of biological particles by counting particles that emit autofluorescence present in sample water, but there is no indicator between the turbidity measurement results and the fluorescent particle counting results. Because they are different, it is difficult to grasp the extent to which fluorescent substances (organisms) influence turbidity by simply comparing the two.

Therefore, an object of the present invention is to provide a technique for specifying turbidity derived from fluorescent substances.

In order to solve the above problems, the present invention employs the following biological particle measuring device and biological particle measuring device. Note that the following words in parentheses are merely examples, and the present invention is not limited thereto.

That is, in the turbidity measuring device and turbidity measuring method of the present invention, light of a predetermined wavelength is irradiated toward the liquid, and scattered light emitted from particles contained in the liquid is selectively received and its intensity is adjusted. In addition to outputting a signal with a size corresponding to the intensity, it also selectively receives fluorescence emitted from particles contained in the liquid and outputs a signal with a size corresponding to its intensity, and the unit is determined based on each output signal. The number of fluorescent particles that emit fluorescence per volume is counted for each predetermined particle size category, and based on the counting results, the turbidity of the liquid resulting from the fluorescent particles is calculated.

In the particle counting method, as is well known, turbidity is measured based on scattered light emitted from particles contained in a liquid. That is, since the only light taken into account in this measurement is scattered light, there is no way to know how much of the measured turbidity is actually derived from microorganisms.

In contrast, in the above embodiment, the turbidity derived from the fluorescent particles (fluorescence turbidity) is calculated based on the scattered light and fluorescence emitted from the particles contained in the liquid. Therefore, according to this aspect, the magnitude of turbidity derived from the fluorescent substance can be specified in the same unit as general turbidity.

Preferably, in the turbidity measuring device and turbidity measuring method described above, the number of particles per unit volume can be further counted for each particle size category, and the turbidity of the liquid can be calculated based on the counted results. It is.

In this embodiment, the number of all particles per unit volume is counted for each particle size category. Alternatively, even if the number of all particles cannot be counted directly, the number of all particles is equal to the sum of the number of fluorescent particles and the number of non-fluorescent particles that do not emit fluorescence, so the number of fluorescent particles and the number of non-fluorescent particles can be calculated. Once the number of particles has been counted, by adding them up, the number of all particles will naturally be counted indirectly.

Moreover, since turbidity is calculated based on all particles, the turbidity is the sum of the fluorescent turbidity and the turbidity originating from particles that do not emit fluorescence (non-fluorescent turbidity). Therefore, if the turbidity is calculated based on the number of all particles in each particle size classification, by subtracting the fluorescent turbidity from this, the non-fluorescent turbidity will also be automatically calculated. In addition, even if turbidity cannot be directly calculated, if non-fluorescent turbidity is calculated based on the number of non-fluorescent particles in each particle size category, turbidity can be automatically calculated by adding this to fluorescent turbidity. The degree will also be calculated indirectly. Therefore, according to this aspect, it is possible to specify turbidity, fluorescent turbidity, and non-fluorescent turbidity, and it is possible to understand the breakdown of turbidity.

More preferably, in the turbidity measuring device and turbidity measuring method described above, the ratio of turbidity derived from fluorescent particles to the turbidity of the liquid is further calculated. Furthermore, at least the proportion of the turbidity derived from the fluorescent particles to the calculated turbidity of the liquid is displayed.

According to this aspect, the ratio of the fluorescent turbidity to the turbidity of the liquid is specified and the value is displayed, so that the degree of influence of the fluorescent substance on the turbidity can be easily grasped.

As described above, according to the present invention, turbidity originating from a fluorescent substance can be specified.

1 is a schematic configuration diagram showing an embodiment of a fluorescence turbidity measurement device. It is a flowchart which shows the example of a procedure of fluorescence turbidity measurement processing. 3 is a flowchart illustrating an example of a procedure of data analysis processing. FIG. 3 is a diagram showing an example of inputting a fluorescence signal and a scattered light signal. It is a flowchart which shows the example of a procedure of particle counting processing. It is a table summarizing the number of fluorescent particles and the number of non-fluorescent particles counted by particle size classification by particle counting processing. It is a table summarizing the number of particles counted by particle size category in a comparative example. It is a flowchart which shows the example of a procedure of a notification process. It is a figure (1/2) showing an example of the display mode of a measurement result. It is a figure (2/2) showing an example of the display mode of a measurement result. It is a figure showing an example of changes in turbidity, the number of fluorescent particles, and the number of non-fluorescent particles, and the ratio of fluorescent turbidity to turbidity (1/2). FIG. 2 is a diagram showing an example of changes in turbidity, the number of fluorescent particles, and the number of non-fluorescent particles, and the ratio of fluorescent turbidity to turbidity (2/2). FIG. 1 is a diagram showing an example of a water purification monitoring system including a fluorescence turbidity measuring device.

Embodiments of the present invention will be described below with reference to the drawings. Note that the following embodiments are preferred examples, and the present invention is not limited to these examples.

FIG. 1 is a diagram schematically showing the configuration of a fluorescence turbidity measuring device 1. As shown in FIG. Here, "fluorescent turbidity" refers to turbidity measured due to particles that emit fluorescence (hereinafter referred to as "fluorescent particles") contained in sample water. On the other hand, "non-fluorescent turbidity" refers to turbidity measured due to particles that do not emit fluorescence (hereinafter referred to as "non-fluorescent particles") contained in sample water. In addition, "fluorescence turbidity measuring device" refers to the measurement of turbidity, fluorescent turbidity, non-fluorescent turbidity, and the proportion of fluorescent turbidity in turbidity (hereinafter, these are collectively referred to as This is a device that performs ``fluorescence turbidity measurement'' and reports the results.

As shown in FIG. 1, the fluorescence turbidity measurement device 1 is broadly comprised of a detection system 2 and a measurement system 3. Of these, the detection system 2 is a part that irradiates light onto sample water and detects light generated by interaction between particles contained in the sample water and the irradiated light. Further, the measurement system 3 is a part that measures fluorescence turbidity based on the light detected by the detection system 2 and notifies the result.

In addition, the fluorescence turbidity measuring device 1 of this embodiment measures turbidity derived from fluorescent particles, which is emitted from substances such as chlorophyll that are necessary for metabolism existing in the cells of phytoplankton such as algae. Autofluorescence is used as an indicator. Furthermore, it is possible to detect particles having a particle size of 0.5 μm to several 100 μm.

[Detection system]
First, the configuration of the detection system 2 will be explained.
The detection system 2 includes, for example, a light emitting means 10, an irradiation lens 20, a flow cell 30, a first condensing lens 40, a light shielding means 50, a scattered light selection optical means 60, a light shielding wall 65, a fluorescence selection optical means 70, a second It is composed of a condensing lens 80, a fluorescent light receiving means 90, a third condensing lens 100, a scattered light receiving means 110, and the like.

The light emitting means 10 is, for example, a semiconductor laser diode or a semiconductor LED element, and emits irradiation light 11 toward the flow cell 30 . As described above, in this embodiment, fluorescence is detected using autofluorescence emitted from a substance such as chlorophyll as an indicator. For example, the excitation wavelength spectrum of chlorophyll a has a distribution with a peak at about 430 nm. In order to excite chlorophyll a, light in the ultraviolet range to the blue visible light range (for example, 330 to 460 nm) is suitable. Therefore, in order to emit more fluorescence, a wavelength of 405 nm is adopted as the wavelength of the irradiation light 11.

An irradiation lens 20 is provided on the optical axis of the irradiation light 11. The irradiation lens 20 is composed of an optical lens such as a collimator lens, a biconvex lens, or a cylindrical lens, and adjusts the spread angle of the irradiation light 11 to be parallel or less and focuses the light inside the flow cell 30 .

The flow cell 30 is formed in a cylindrical shape from a transparent material such as quartz or sapphire, and the inside thereof serves as a flow path for sample water. For example, sample water containing fluorescent particles _Pf and non-fluorescent particles _Ps is poured into the flow cell 30, which is obtained by separating water in the water purification process.

When the light emitting means 10 irradiates the irradiation light 11 toward the flow cell 30 into which the sample water has been poured, the irradiation light 11 is focused by the irradiation lens 20 and enters the flow cell 30 . As a result, a detection region for detecting light generated from the fluorescent particles P _f and the non-fluorescent particles P _s is formed at a predetermined position within the flow cell 30 . When the irradiated light 11 is absorbed by chlorophyll a in the cells of the fluorescent particles P _f , fluorescence in the wavelength range of 630 to 710 nm is emitted. Further, the wavelength distribution of fluorescence emitted from the fluorescent particles P _f has a peak at about 670 nm.

A light shielding means 50 is provided at a position in front of the optical axis of the irradiated light 11, that is, at a position opposite to the light emitting means 10 via the flow cell 30. The light blocking means 50 is, for example, a beam damper or a beam trap, and blocks and absorbs the irradiation light 11 that has passed through the flow cell 30.

On the other hand, a first condensing lens 40 is disposed at a position lateral to the optical axis of the irradiated light 11. The first condensing lens 40 condenses light generated by the interaction between the fluorescent particles P _f and the non-fluorescent particles P _s and the irradiation light 11 within the flow cell 30 . In order to collect as much light as possible, it is preferable that the aperture of the lens be large.

The light focused by the first focusing lens 40 enters the scattered light selection optical means 60. The scattered light selection optical means 60 is, for example, a dichroic mirror. In this embodiment, for example, a dichroic mirror with a cutoff wavelength of 410 nm is employed. Since the scattered light emitted from the fluorescent particles _Pf and the non-fluorescent particles _Ps has the same wavelength as the irradiation light 11, by arranging such a scattered light selection optical means 60, it is possible to emit the fluorescent particles _Pf and the non-fluorescent particles. While reflecting the scattered light emitted from the particles P _s , other light including fluorescence emitted from the fluorescent particles P _f can be transmitted.

Fluorescence selection optical means 70 is arranged on the optical axis of the light transmitted through scattered light selection optical means 60. The fluorescence selection optical means 70 is, for example, a long pass filter. In this embodiment, since chlorophyll a having a fluorescence spectrum with a peak at about 670 nm is used as an index, a long-pass filter with a cutoff wavelength of 600 nm is adopted accordingly. Note that the cutoff wavelength of the long-pass filter is not limited to this, and a wavelength that can cut more light having a shorter wavelength than fluorescence (such as Raman scattered light) may be selected. Furthermore, instead of a long-pass filter, a band-pass filter that transmits light in a predetermined wavelength range may be used, or a band-pass filter that transmits light with a wavelength longer than the predetermined wavelength while reflecting light with a shorter wavelength may be used. A dichroic mirror may also be used.

A second condensing lens 80 is arranged on the optical axis of the light transmitted through the fluorescence selection optical means 70. The second condensing lens 80 condenses the light that has passed through the fluorescence selection optical means 70 and makes it enter the fluorescence light receiving means 90 . The light transmitted through the fluorescence selection optical means 70 includes, in addition to the fluorescence from the fluorescent particles _Pf , Raman scattered light that was not cut by the fluorescence selection optical means 70. Note that the optical path from passing through the scattered light selection optical means 60 to reaching the fluorescent light receiving means 90 is covered with a light shielding wall 65. The light shielding wall 65 is, for example, a cylindrical structure. The light shielding wall 65 can prevent light from other sources from entering the fluorescent light receiving means 90.

The fluorescence receiving means 90 is, for example, a photodiode (PD, semiconductor optical element) or a photomultiplier tube (PMT, photomultiplier tube), and is configured to receive a signal by a voltage value corresponding to the intensity (amount of light) of the incident light. Outputs electrical signals. Note that the electrical signal output by the fluorescence receiving means 90 is input to the measurement system 3.

On the other hand, the third condensing lens 100 is arranged on the optical axis of the light reflected by the scattered light selection optical means 60, that is, the scattered light. The third condensing lens 100 condenses the scattered light and makes it enter the scattered light receiving means 110 . Note that the optical path from the reflection side of the scattered light selection optical means 60 to the scattered light reception means 110 is also covered with a light-blocking wall in the same way as the optical path from the transmission side of the scattered light selection optical means 60 to the fluorescence reception means 90. 65 may be provided.

The scattered light receiving means 110 is, for example, a photodiode (PD, semiconductor optical element) or a photomultiplier tube (PMT, photomultiplier tube), and has a voltage value corresponding to the intensity (light amount) of the incident light. outputs an electrical signal. Note that the electrical signal output by the scattered light receiving means 110 is input to the measurement system 3.

[Measurement system]
Next, the configuration of the measurement system 3 will be explained.
The measurement system 3 includes, for example, a signal processing unit 200, a data processing unit 300, a notification unit 400, and the like. Of these, the signal processing unit 200 converts the electrical signal input by the detection system 2 (fluorescence light receiving means 90, scattered light receiving means 110) into a form suitable for analysis. Furthermore, the data processing unit 300 counts the number of fluorescent particles and the number of non-fluorescent particles for each particle size classification based on the converted signal data, and then calculates the fluorescence turbidity based on the counting results. The notification unit 400 then reports the processed results.

Next, the contents of the processing executed by the individual units 200, 300, and 400 will be explained in more detail.

[Fluorescence turbidity measurement processing]
FIG. 2 is a flowchart showing an example of a procedure for fluorescence turbidity measurement processing. The fluorescence turbidity measurement process is a process executed by the measurement system 3. The procedure will be explained below using an example procedure.

Step S10: First, the signal processing unit 200 executes data collection processing. Specifically, when an electrical signal is received from the fluorescent light receiving means 90, the first amplifier 212 in the fluorescent signal processing section 210 amplifies the received electrical signal by a predetermined amplification factor, and the first A/D converting section 214 converts the amplified electrical signal (analog signal) into a digital signal. Further, upon receiving the electrical signal from the scattered light receiving means 110, in the scattered light signal processing section 220, the second amplifier 222 amplifies the received electrical signal with a predetermined amplification factor, and the second A/D converting section 224 Converts the amplified electrical signal (analog signal) into a digital signal. The digital signals converted by each A/D converter 214 and 224 are input to the data processing unit 300.

In the following description, the digital signal converted by the first A/D converter 214 will be referred to as a "fluorescent signal", and the digital signal converted by the second A/D converter 224 will be referred to as a "scattered light signal". That's it.

Step S20: Next, the data processing unit 300 executes data analysis processing. In this process, the data storage section 310 stores the input fluorescence signal and scattered light signal, and the data analysis section 320 performs data analysis based on these signals.

Step S30: Then, the data processing unit 300 executes analysis result output processing. In this process, the result output section 330 stores the latest measurement results analyzed by the data analysis section 320 in the data storage section 310 and inputs them to the notification unit 400. In addition, the result output unit 330 can also output the measurement results to a printer or transmit them to another device via a network.

Step S40: Finally, the notification unit 400 executes notification processing. In this process, the notification unit 400 reports the latest input measurement results.

Note that the specific contents of the data analysis process and the notification process will be described in detail later with reference to other drawings.

[Data analysis processing]
FIG. 3 is a flowchart showing an example of the procedure of data analysis processing. The procedure will be explained below using an example procedure.

Step S100: The data processing unit 300 executes signal storage processing. In this process, the data storage section 310 stores the fluorescence signal and scattered light signal input by the signal processing unit 200 (first A/D conversion section 214, second A/D conversion section 224). That is, the substance of the data storage unit 310 is a storage area (memory).

Step S110: The data processing unit 300 executes particle counting processing. In this process, the data analysis unit 320 counts the number of fluorescent particles and the number of non-fluorescent particles for each particle size classification based on the fluorescence signal and scattered light signal input at the same time.

[Example of input of fluorescence signal and scattered light signal]
FIG. 4 is a diagram showing an example of inputting a fluorescence signal and a scattered light signal.

The upper part of FIG. 4 shows the time-varying distribution of the fluorescent signal _VA that has been A/D converted and input to the data processing unit 300 in accordance with the electrical signal from the fluorescent light receiving means 90. A threshold value A (V _thA ) is provided for the peak value of the fluorescence signal _VA . By the way, as described above, the light that has passed through the fluorescence selection optical means 70 is incident on the fluorescence reception means 90, but the incident light includes, in addition to the fluorescence _L1 , Raman light that has not been cut by the fluorescence selection optical means 70. A small amount of light _L2 such as scattered light is included. Therefore, strictly speaking, the magnitude of the fluorescence signal V _A corresponds to the light amount L _t that is the sum of the light amounts of the fluorescence L ₁ and other light L ₂ .

Furthermore, the lower part of FIG. 4 shows the time-varying distribution of the scattered light signal _VB that is A/D converted and input to the data processing unit 300 in accordance with the electrical signal from the scattered light receiving means 110. In this embodiment, in order to count the number of fluorescent particles and the number of non-fluorescent particles in each of n particle size categories, n thresholds are provided for the peak value of the scattered light signal _VB , and The peak value of _VB is classified into n particle size categories. Among the n threshold values, the smallest threshold value B1 (V _thB1 ) is a value corresponding to 0.5 μm, which is the minimum value of the particle size that the fluorescence turbidity measuring device 1 can detect.

In order to facilitate understanding of the invention, an example in which there are five particle size classifications will be described here. The five particle size categories include, for example, a first particle size category D ₁ in which particles with a particle size d of 0.5 μm or more and less than 1.0 μm are classified, and a particle size d of 1.0 μm or more and 2.0 μm. A second particle size division D ₂ in which particles with a particle size d _of less than A fourth particle size division D ₄ in which particles with a particle size of less than 5.0 μm are classified, and a fifth particle size division D ₅ in which particles with a particle size d of 5.0 μm or more are classified are set. In this case, five threshold values B1 (V _thB1 ) to B5 (V _thB5 ) are provided for the scattered light signal V _B . Among these, the threshold value B1 (V _thB1 ) is a value corresponding to 0.5 μm, the threshold value B2 (V _thB2 ) is a value corresponding to 1.0 μm, and the threshold value B3 (V _thB3 ) is a value corresponding to 2.0 μm. The threshold value B4 (V _thB4 ) is a value corresponding to 0.3 μm, and the threshold value B5 (V _thB5 ) is a value corresponding to 5.0 μm.

In particle counting processing, if the peak value of the scattered light signal _VB is greater than or equal to the threshold value B1, and the peak value of the fluorescent signal _VA input at the same time as the scattered light signal _VB is greater than or equal to the threshold value A, The light input at this timing is determined to be light emitted from the fluorescent particles _Pf , and the number of fluorescent particles is incremented by 1. On the other hand, if the peak value of the scattered light signal _VB is greater than or equal to the threshold value _B1 , but the peak value of the fluorescent signal VA input at the same time as the scattered light signal _VB is less than the threshold value A, this timing The input light is determined to be light emitted from the non-fluorescent particles _Ps , and 1 is added to the number of non-fluorescent particles.

For example, at time t1, the peak value of the scattered light signal V _B is greater than or equal to the threshold value B1, but the peak value of the fluorescent signal VA is less than the threshold value _A , so 1 is added to the non-fluorescent particles. Furthermore, at time t2, the peak value of the scattered light signal V _B is greater than or equal to the threshold value B1, and the peak value of the fluorescent signal _VA is greater than or equal to the threshold value A, so that the number of fluorescent particles is added by one.

[Particle counting process]
FIG. 5 is a flowchart illustrating an example of a procedure for particle counting processing. The procedure will be explained below using an example procedure.

Step S200: When the peak value of the scattered light signal _VB is greater than or equal to the threshold value B1, the data analysis unit 320 branches the process depending on the magnitude of the peak value of the scattered light signal _VB . Specifically, when the peak value of the scattered light signal _VB is greater than or equal to the threshold value B1 and less than the threshold value B2, the data analysis unit 320 classifies the detected particles into the first particle size classification _D1 ( Step S210), if the peak value of the scattered light signal _VB is greater than or equal to the threshold value B2 and less than the threshold value B3, the detected particles are classified into the second particle size classification _D2 (step S212), and the scattered light signal If the peak value of _VB is greater than or equal to the threshold B3 and less than the threshold B4, the detected particles are classified into the third particle size classification _D3 (step S214), and the peak value of the scattered light signal _VB is set to the threshold. B4 or more and less than the threshold B5, the detected particles are classified into the fourth particle size classification _D4 (step S216), and if the peak value of the scattered light signal _VB is more than the threshold B5, , the detected particles are classified into the fifth particle size classification _D5 (step S218). Note that since the threshold value B1 corresponds to the minimum value of the detectable particle size, there is no need to process the case where the particle size is less than the threshold value B1.

Step S220: Next, the data analysis unit 320 checks whether the peak value of the fluorescence signal _VA input at the same time as the scattered light signal _VB is equal to or greater than the threshold value A. As a result of the confirmation, if the peak value of the fluorescence signal _VA is equal to or greater than the threshold value A (step S220: Yes), the data analysis unit 320 next executes step S230. On the other hand, if the peak value of the fluorescence signal _VA is less than the threshold A (step S220: No), the data analysis unit 320 next executes step S232.

Step S230: The data analysis unit 320 adds 1 to the number of fluorescent particles in the particle size categories classified according to the magnitude of the peak value of the scattered light signal _VB .

Step S232: The data analysis unit 320 adds 1 to the number of non-fluorescent particles in the particle size categories classified according to the magnitude of the peak value of the scattered light signal _VB .

By repeatedly performing the above procedure, the number of fluorescent particles and the number of non-fluorescent particles per unit volume are counted for each particle size classification. Further, by adding together the counted number of fluorescent particles and the number of non-fluorescent particles, the total number of particles per unit volume is calculated for each particle size classification.

Note that the above procedure example is just an example and is not limited thereto. For example, in the above procedure example, the number of fluorescent particles and the number of non-fluorescent particles are counted, but instead of this, the total number of particles and the number of fluorescent particles may be counted. In this case, by subtracting the number of fluorescent particles from the total number of particles counted, the number of non-fluorescent particles per unit volume can be calculated for each particle size category.

[Counting results by particle size classification: embodiment]
FIG. 6 is a table summarizing the number of fluorescent particles and the number of non-fluorescent particles counted for each particle size category by the particle counting process (FIG. 5).

The number of fluorescent particles classified into the first particle size classification _D1 is _Nf1 , and the number of non-fluorescent particles is _Ns1 . Furthermore, from the sum of these counts, the total number of particles classified into the first particle size classification D ₁ is calculated as N ₁ (=N _f1 +N _s1 ).

The number of fluorescent particles classified into the second particle size classification _D2 is _Nf2 , and the number of non-fluorescent particles is _Ns2 . Furthermore, from the sum of these counts, the total number of particles classified into the second particle size classification D ₂ is calculated as N ₂ (=N _f2 +N _s2 ).

The number of fluorescent particles classified into the third particle size classification _D3 is _Nf3 , and the number of non-fluorescent particles is _Ns3 . Furthermore, from the sum of these counts, the total number of particles classified into the third particle size classification _D3 is calculated as _N3 (= _Nf3 + _Ns3 ).

The number of fluorescent particles classified into the fourth particle size classification _D4 is _Nf4 , and the number of non-fluorescent particles is _Ns4 . Furthermore, from the sum of these counts, the total number of particles classified into the fourth particle size classification _D4 is calculated as _N4 (= _Nf4 + _Ns4 ).

The number of fluorescent particles classified into the fifth particle size classification _D5 is _Nf5 , and the number of non-fluorescent particles is _Ns5 . Furthermore, from the sum of these counts, the total number of particles classified into the fifth particle size classification D ₅ is calculated as N ₅ (=N _f5 +N _s5 ).

Here, since both the number of fluorescent particles and the number of non-fluorescent particles for each particle size classification are counted as the number of particles per unit volume, each count value can be directly read as the number concentration.

In the present embodiment, turbidity and fluorescence turbidity are calculated based on the counting results for each particle size category according to the particle counting method. In the table of FIG. 6, the particle sizes r ₁ to r ₅ shown immediately below each particle size category D ₁ to D ₅ are used as the particle size of each particle size category when calculating turbidity. Here, as an example, the median value of the particle size range in the corresponding particle size category is used as the value of particle diameters r ₁ to r ₅ . For example, the particle size r ₁ of the first particle size classification D ₁ is “0.75 μm” which is the median value of “0.5 μm or more and less than 1.0 μm”. However, the particle size r ₅ of the fifth particle size division D ₅ is set to a predetermined value of "7.0 μm" because the particle size range has no upper end and the median value cannot be determined. Note that the values used as the particle sizes r ₁ to r ₅ are not limited to the median values of the particle size range. For example, the minimum value may be used instead of the median value.

[Turbidity calculation process: see Figure 3]
Step S120: The data processing unit 300 executes turbidity calculation processing. In this process, the data analysis unit 320 divides the number of particles by particle size category according to the particle counting method based on the total number of particles by particle size category calculated as a result of step S110 (particle counting process: FIG. 5) described above. Turbidity is calculated using a known formula for calculating the sum of the products of the number concentration and the average scattering cross section.

In calculating turbidity, the number concentration of each particle size category is calculated based on the total number of particles N ₁ to N ₅ for each particle size category and the flow rate. Further, the average scattering cross section of each particle size category can be calculated based on the particle sizes r ₁ to r ₅ of each particle size category.

Step S130: The data processing unit 300 executes fluorescence turbidity calculation processing. In this process, the data analysis unit 320 calculates fluorescence turbidity based on the number of fluorescent particles for each particle size category calculated as a result of step S110 (particle counting process: FIG. 5) described above.

Fluorescence turbidity is also calculated using the same formula as when calculating turbidity. In addition, in calculating the fluorescence turbidity, the number concentration of each particle size category is calculated based on the number of fluorescent particles N _f1 to N _f5 for each particle size category and the flow rate. Further, the average scattering cross section of each particle size category can be calculated based on the particle sizes r ₁ to r ₅ of each particle size category.

Step S140: The data processing unit 300 executes non-fluorescent turbidity calculation processing. In this process, the data analysis unit 320 calculates non-fluorescent turbidity by subtracting the fluorescent turbidity calculated in step S130 from the turbidity calculated in step S120.

Note that instead of calculating non-fluorescent turbidity as the difference between turbidity and fluorescent turbidity, it is also possible to calculate it using the same formula as when calculating turbidity and fluorescent turbidity. In calculating the non-fluorescent turbidity in that case, the number concentration in each particle size category is calculated based on the number of non-fluorescent particles N _s1 to N _s5 for each particle size category and the flow rate.

Step S150: The data processing unit 300 executes a ratio calculation process. In this process, the data analysis unit 320 calculates the respective proportions of fluorescent turbidity and non-fluorescent turbidity in the turbidity based on the turbidity, fluorescent turbidity, and non-fluorescent turbidity calculated in steps S120 to S140. do.

According to the above procedure, turbidity, fluorescent turbidity, non-fluorescent turbidity, and each ratio of fluorescent turbidity and non-fluorescent turbidity to turbidity are calculated. This makes it possible to specify the degree of influence of fluorescent particles (biological particles) on turbidity.

[Counting results by particle size classification: comparative example]
FIG. 7 is a table summarizing the number of particles counted by particle size category in the comparative example. The comparative example corresponds to a general turbidity meter that measures turbidity using a particle counting method.

In the comparative example, the number of particles is counted by particle size category based only on scattered light. Then, turbidity will be calculated based on the counting results. Therefore, only turbidity is calculated, and it is impossible to specify fluorescent turbidity or the degree of influence of fluorescent particles (biological particles) on turbidity.

[Notification processing]
FIG. 8 is a flowchart showing an example of the procedure of notification processing. The procedure will be explained below using an example procedure.

Step S300: The notification unit 400 checks whether it is time to update the notification. In the fluorescence turbidity measurement device 1, measurement of fluorescence turbidity and storage of the results are continuously performed, and the latest measurement results are notified (an update timing of the notification occurs every time the measurement results are updated). The configuration is also such that notification of measurement results can be performed at preset fixed time intervals (for example, at intervals of several minutes). If a setting regarding a certain period of time is made, the update timing of the notification occurs every certain period of time.

As a result of the confirmation, if it is the notification update timing (step S300: Yes), the notification unit 400 next executes step S310. On the other hand, if it is not the notification update timing (step S300: No), the notification unit 400 ends the process without executing anything.

Step S310: The notification unit 400 executes display update processing. In this process, the notification unit 400 causes the display 410 to display the latest measurement results on the screen. Note that the display mode of the measurement results will be further described later using another drawing.

Step S320: Notification unit 400 executes notification sound output processing. In this process, the notification unit 400 outputs a predetermined notification sound from the speaker 320, thereby notifying the user that the display screen has been updated. In addition to this, if the latest measurement result satisfies a predetermined condition (for example, if the fluorescence turbidity exceeds a predetermined value, or if the percentage of fluorescence turbidity exceeds a predetermined percentage, etc.), A predetermined warning sound may be output. Further, the warning sound may be made different depending on the content of the warning.

[Measurement result display format]
9 and 10 are diagrams showing an example of a display mode of measurement results displayed on the screen of the display 410.

(A) in FIG. 9: Turbidity, fluorescence turbidity, and the ratio of fluorescence turbidity to turbidity are represented in a pie chart. Looking at the illustrated display example, the turbidity is "0.00016", the fluorescent turbidity is "0.00005", and the proportion of the fluorescent turbidity to the turbidity is "31%". I understand. By displaying it as a pie chart, it gives a visual impact and makes it easy to understand the proportion of fluorescent turbidity in turbidity.

(B) in FIG. 9: Fluorescent turbidity and non-fluorescent turbidity are expressed in a band graph together with an indicator that takes the sum of both as 100%. Looking at the illustrated display example, it can be seen that the fluorescent turbidity is "0.00005" and the non-fluorescent turbidity is "0.00011". Further, although the respective ratios of fluorescent turbidity and non-fluorescent turbidity are not shown numerically, the approximate ratio can be grasped from the size of the width occupied in the band graph. By displaying as a band graph in this way, each ratio of fluorescent turbidity and non-fluorescent turbidity can be grasped intuitively.

Figure 10: Changes in fluorescent turbidity and non-fluorescent turbidity over time are shown in an area graph. Looking at the displayed example shown, non-fluorescent turbidity does not show much change except for local fluctuations, while fluorescent turbidity shows periods of gradual rise and periods of sharp decline. You can see that there is a belt. By displaying the area graph in this way, it is possible to check the time-series trends of fluorescent turbidity and non-fluorescent turbidity while comparing them.

Note that these display modes are given as examples, and the measurement results may be displayed in other modes. Further, the number of digits after the decimal point, the scale interval of the graph, etc. may be changed as appropriate depending on the situation.

Figures 11 and 12 show the changes in turbidity, the number of fluorescent particles, and the number of non-fluorescent particles measured by the fluorescent turbidity measuring device 1 from evening to early morning at a water treatment plant, as well as the turbidity at four points in time. It is a figure which shows an example of the ratio of fluorescence turbidity occupied.

In both figures, the line graph in the upper row shows the change in turbidity of the sample water, and the line graph in the lower row shows the number concentration of fluorescent particles and non-fluorescent particles (the number of fluorescent particles per 10 mL of sample water N _f and the number of non-fluorescent particles N _s ). Furthermore, each of the four pie charts shows the proportion of fluorescence turbidity in the turbidity at the corresponding time point.

Figure 11: Shows the transition of measured values measured at water purification plant A from the evening of June 13th to the early morning of June 14th. The line graph shows that there is no major change in turbidity between 4:30pm and 7pm, but when comparing the two pie charts on the left, it was 31% at the beginning of this timeframe. It can be seen that the fluorescence turbidity reached 76% at the end of the process, indicating a significant increase. Also, looking at the line graph, the number of fluorescent particles N _f changes at a high value from night to midnight, and the turbidity also changes at a high value along with this, reaching its maximum around 3 o'clock, but from the right From the second pie chart, it can be seen that the fluorescence turbidity at this point had reached "94%". Also, looking at the line graph, the number of fluorescent particles _Nf decreases rapidly from around 5 o'clock to early morning, and the turbidity also decreases rapidly. The fluorescence turbidity was 80%, indicating that even after the turbidity decreased, fluorescent particles (biological particles) still influenced the turbidity at a high rate.

Figure 12: Shows the transition of measured values measured at water purification plant B from the evening of June 17th to the early morning of June 18th. Looking at the line graph, we can see that while the number of fluorescent particles _Nf changes at a high value from night to midnight, there are several time periods where the number of non-fluorescent particles _Ns locally fluctuates wildly. Although the turbidity value remains high, it fluctuates wildly in some areas. Following the four pie charts in order, the fluorescence turbidity was "35%" around 5:00 p.m., but it became "52%" before 7:00 p.m., and the turbidity reached its maximum at 3:00 p.m. By then, it had reached 79%, but by 9 o'clock, when the turbidity had dropped, it had dropped to 36%.

In both FIGS. 11 and 12, the shape of the line graph showing the change in turbidity is exactly the shape of the line graph showing the change in the number of fluorescent particles _Nf and the line graph showing the change in the number of non-fluorescent particles _Ns . It has a shape that seems to fit together. From this, it is possible to infer that turbidity is somehow linked to the number concentration of fluorescent particles and non-fluorescent particles. However, while the unit of turbidity is "degrees", the unit of number concentration is "particles/mL", so simply comparing the two values does not allow fluorescent particles (biological particles) to become turbid. It is difficult to ascertain the extent to which these effects are being exerted.

In contrast, in this embodiment, after the fluorescence turbidity is measured, the value of the fluorescence turbidity and the ratio of the fluorescence turbidity to the turbidity are graphed. Therefore, according to the present embodiment, turbidity and fluorescent turbidity can be compared under the same index from the display of measurement results, and the degree of influence of fluorescent particles (biological particles) on turbidity can be easily grasped. becomes possible.

In addition, if the measurement results show that although the turbidity remains at a low value, the proportion of fluorescent turbidity in the turbidity is starting to increase, the amount of inflow of organisms will increase and the turbidity will rise. This makes it possible to detect signs of a rise in turbidity and take measures at an early stage to prevent a rise in turbidity. If countermeasures can be taken at an early stage, not only can an increase in turbidity be prevented, but the amount of chemicals injected can also be kept to the minimum necessary, resulting in a reduction in the cost required for turbidity management. This can lead to reductions.

[Water purification system equipped with a fluorescence turbidity measuring device]
Finally, further examples of utilization of the fluorescence turbidity measuring device 1 will be explained.
FIG. 13 is a diagram showing an example of a water purification system 500 including the fluorescence turbidity measuring device 1.

The water purification system 500 can be realized using, for example, common water purification plant equipment. As is well known, in a typical water purification plant, water is taken from various water sources 502 such as rivers, lakes, dams, etc., and the raw water is transferred to a settling basin 504, a landing well 504, and then to a coagulant injection facility 508 where it is coagulated. Chlorine is injected with the agent. Thereafter, the water is stored in a settling tank 510, and then passes through a chlorine injection facility 512 and chlorine is injected therein. The water after chlorine injection is filtered in a filter basin 514, and then passes through another chlorine injection equipment 516 where chlorine is injected again. The water purified in this manner is transferred from the water distribution reservoir 518 to the water supply device 520, and is sent to each home through the water supply pipes.

The water purification system 500 also includes a coagulant injection facility 508 and two chlorine injection facilities 512 and 516, as well as a drug supply device 530, a drug adjustment device 540, and a central monitoring and control device 560. Among these, the drug supply device 530 is a supply source of the drugs injected by the flocculant injection equipment 508 and the chlorine injection equipment 512 and 516. The supply amount of the medicine supplied from the medicine supply device 530 is adjusted by the medicine adjustment device 540, and then sent to the flocculant injection equipment 508 and the chlorine injection equipment 512, 516. The central monitoring and control device 560 also controls the adjustment of the drug supply amount by the drug adjustment device 540.

In such a water purification system 500, for example, a diversion device 550 that diverts water from the vicinity of the outlet of the water landing well 506 or the vicinity of the outlet of the filtration basin 514 is installed, and the diverted water is poured into the fluorescence turbidity measuring device 1. The fluorescence turbidity measurement device 1 measures the fluorescence turbidity of the diverted water, that is, the water that passes through these positions and moves on to the next process, and sends the measurement results to the central monitoring and control device 560 via the network. do. In response to this, the central monitoring and control device 560 determines the type of drug to be supplied from the drug adjustment device 540 to each injection facility 508, 512, 516 according to the measured fluorescent turbidity and non-fluorescent turbidity. It becomes possible to control the supply amount in real time.

Next, drug control will be specifically explained.

The drug supply device 530 is a tank that stores multiple types of drugs, such as a flocculant such as polyaluminum chloride (PAC) used to coagulate and precipitate fine sand, soil, etc. mixed in water, and a disinfectant. Disinfectants such as sodium hypochlorite (chlorine) used for disinfection are stored. These drugs supplied from the drug supply device 530 are sent to the drug adjustment device 540 through a water pipe. Although not shown, there are two water pipes for connecting the drug supply device 530 and the drug adjustment device 540, one for flocculant and one for disinfectant.

The drug adjustment device 540 is a device that adjusts the flow rate of various drugs supplied from the drug supply device 530 and sends it to the flocculant injection equipment 508 and each chlorine injection equipment 512, 516, and controls the adjustment valves 542, 544, 546. have. Regulating valve 542 is connected to a water pipe between drug supply device 530 and flocculant injection equipment 508 . Note that although not shown, since the flocculant and chlorine are injected into the flocculant injection equipment 508, there are two systems of water pipes that connect the chemical supply device 530 and the flocculant injection equipment 508, and the adjustment valve 542 The flow rate of each system can be adjusted. Further, the adjustment valve 544 is connected to the water pipe between the chemical supply device 530 and the chlorine injection equipment 512, and the adjustment valve 546 is connected to the water pipe between the chemical supply device 530 and the chlorine injection equipment 516. There is. The chemical adjustment device 540 individually adjusts the flow rate of the chemical sent to the coagulant injection equipment 508 and each chlorine injection equipment 512, 516 using adjustment valves 542, 544, 546 based on instructions from the central monitoring and control device 560.

The central monitoring and control device 560 determines in real time the type of drug to be supplied to each injection facility 508, 512, 516 and the amount thereof to be supplied, according to the received counting results. For example, if the fluorescence turbidity is high, it is assumed that a large amount of algae, etc. is contained, and an increase in the amount of chlorine supplied is determined. Further, for example, if the non-fluorescent turbidity is high, it is assumed that a large amount of non-living contaminants is contained, and it is determined to increase the supply amount of flocculant and decrease the supply amount of chlorine. Then, the central monitoring and control device 560 instructs the drug adjusting device 540 to adjust the amount of drug supplied based on the determined content.

As described above, according to the water purification system 500 equipped with the fluorescence turbidity measuring device 1, the flocculant injection equipment 508 and each chlorine injection equipment 512, 516 and the amount thereof can be varied, and water quality can be efficiently managed in the water purification process. Further, since the amount of medicine supplied is appropriately controlled depending on the situation, the amount of medicine supplied can be suppressed to the necessary minimum, and the cost required for water purification treatment can be reduced.

In addition, in the example mentioned above, although the fluorescence turbidity measuring device 1 is installed near the exit of the landing well 506 and the exit of the filtration basin 514, the installation location is not limited to this. For example, in addition to these, it may also be installed near the outlet of the settling tank 510. Alternatively, it is also possible to install it in at least one location near each outlet of the landing well 506, the settling basin 510, and the filtration basin 514. In addition to water purification systems, it can also be used to monitor the turbidity of industrial water and mineral water.

[Advantages of the present invention]
As described above, according to the embodiment described above, the following effects can be obtained.
(1) The number of fluorescent particles is counted for each particle size category, and the fluorescent turbidity is calculated based on this, so the size of the turbidity derived from the fluorescent particles can be calculated using general turbidity and indicators. Can be specified in the same unit.

(2) Turbidity, fluorescent turbidity, and non-fluorescent turbidity are calculated based on the number of fluorescent particles, the number of non-fluorescent particles, and the total number of particles counted for each particle size category. and fluorescence turbidity can be compared under the same index.

(3) Since the respective proportions of fluorescent turbidity and non-fluorescent turbidity in turbidity are calculated, it is possible to specify the degree of influence of fluorescent particles (biological particles) on turbidity.

(4) Since the measurement results are displayed in a graph together with numerical values, it is possible to intuitively grasp the proportion of fluorescent turbidity in turbidity and the time-series changes in fluorescent turbidity and non-fluorescent turbidity.

(5) It is possible to detect signs of an increase in turbidity from changes in the fluorescence turbidity displayed as measurement results, and take measures at an early stage to prevent the increase in turbidity. This can prevent an increase in turbidity. Furthermore, if countermeasures are taken at an early stage, the amount of chemical input can be suppressed to the necessary minimum, making it possible to reduce the cost required for turbidity management.

(6) In the water purification system, by measuring the fluorescence turbidity of water in the water purification process using the fluorescence turbidity measuring device 1, and controlling the type and amount of chemicals to be added according to the measurement results, Water quality management in water purification treatment can be performed efficiently. Moreover, the amount of medicine supplied can be suppressed to the necessary minimum, and the cost required for water purification treatment can be reduced.

The present invention is not limited to the embodiments described above, and can be implemented with various modifications.

The wavelength of the irradiation light 11 and the cutoff wavelengths of the scattered light selection optical means 60 and the fluorescence selection optical means 70 in the embodiment described above are merely examples, and may be changed depending on the situation without being limited thereto. It can be changed as appropriate.

In the embodiment described above, fluorescence is detected using chlorophyll or the like as an indicator, but other substances may be used as an indicator instead. In that case, the wavelength of the irradiation light 11 and the cutoff wavelengths of the scattered light selection optical means 60 and the fluorescence selection optical means 70 may be changed depending on the substance to be used as an index.

In the embodiment described above, measurement results at a water purification plant are exemplified, but the place where the fluorescence turbidity measuring device 1 is used is not limited to a water purification plant, but may be used in other places where appropriate management of water quality is required (e.g. , swimming pools, etc.).

In addition, the materials, numerical values, etc. cited as examples of each component of the fluorescence turbidity measuring device 1 are merely examples, and it goes without saying that modifications can be made as appropriate when implementing the present invention.

1 Fluorescence turbidity measuring device 2 Detection system 3 Measurement system 10 Light emitting means 20 Lens for irradiation 30 Flow cell 40 First light collecting lens 50 Light shielding means 60 Scattered light selection optical means 65 Light shielding wall 70 Fluorescence selection optical means 80 Second light collection lens 90 Fluorescence light receiving means 100 Third condensing lens 110 Scattered light receiving means 200 Signal processing unit 300 Data processing unit 400 Notification unit 500 Water purification system

Claims (5)

a light emitting means for irradiating light toward the liquid;
a scattered light receiving means for selectively receiving scattered light emitted from particles contained in the liquid and outputting a signal having a magnitude corresponding to the intensity thereof;
Fluorescence receiving means for selectively receiving fluorescence emitted from particles contained in the liquid and outputting a signal having a size corresponding to the intensity thereof;
Based on the signals output by the scattered light receiving means and the fluorescence receiving means, the number of particles per unit volume and the number of fluorescent particles emitting fluorescence per unit volume are determined for each predetermined particle size classification. particle counting means for counting;
Based on the counting result by the particle counting means, calculate the turbidity of the liquid and the turbidity originating from the fluorescent particles of the liquid, and calculate the ratio of the turbidity originating from the fluorescent particles to the turbidity of the liquid. turbidity calculation means ,
a result display means for displaying at least a proportion of the turbidity derived from the fluorescent particles to the turbidity of the liquid;
Turbidity measuring device equipped with The turbidity measuring device according to claim 1,
The result display means includes:
A turbidity measuring device that visually represents a proportion of turbidity derived from the fluorescent particles to the turbidity of the liquid. a light emitting process of irradiating light toward the liquid;
It selectively receives scattered light emitted from particles contained in the liquid and outputs a signal of a size corresponding to its intensity, and selectively receives fluorescence emitted from the particles and outputs a signal corresponding to its intensity. a light receiving process that outputs a signal of a corresponding size;
a particle counting step of counting the number of particles per unit volume and the number of fluorescent particles emitting fluorescence per unit volume for each predetermined particle size classification based on each signal output in the light receiving step;
Based on the results counted in the particle counting step, calculate the turbidity of the liquid and the turbidity derived from the fluorescent particles of the liquid, and calculate the ratio of the turbidity derived from the fluorescent particles to the turbidity of the liquid. a turbidity calculation step for calculating the
a result display step of displaying at least a proportion of the turbidity derived from the fluorescent particles to the turbidity of the liquid calculated in the turbidity calculation step;
Turbidity measurement methods including. In the turbidity measurement method according to claim 3,
In the result display step,
A turbidity measuring method, characterized in that the ratio of turbidity originating from the fluorescent particles to the turbidity of the liquid is visually expressed. In water purification facilities that purify water,
The turbidity measuring device according to claim 1 or 2 is installed on a waterway in a water purification process,
A water purification monitoring system characterized in that the type or amount of medicine to be injected in the water purification process is determined based on the turbidity calculated by the turbidity measuring device.

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