JP2017072404A - Flocculation monitoring device, flocculation monitoring method, flocculation treatment system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flocculation monitoring device and a flocculation monitoring method which can measure a flocculation state in a flocculation treatment of treated water with high concentration of suspended solids (SS).SOLUTION: A measurement light irradiation part (laser beam irradiation part 10) irradiates a measurement area (18) of treated water (8) with measurement light, and a scattered light reception part (laser beam reception part 12) receives light scattered by particles (flocs 70) of the treated water, which exist in the measurement area. A measurement value calculation part (calculator 48) obtains an index of a flocculation state of the treated water from a change of a light reception level (scattered light level) of the scattered light in each flocculation treatment, which can be acquired by the scattered light reception part.SELECTED DRAWING: Figure 1

Description

The present invention relates to, for example, a monitoring technique for aggregating treatment of water to be treated such as purified water, industrial water, and wastewater, and a technique for using the same.

  In the flocculation treatment of treated water such as purified water, industrial water, and wastewater, for example, SS (Suspended Solid) in the treated water is flocculated by inorganic flocculant or organic flocculant, and then separated by precipitation and pressurized. Solid-liquid separation such as levitation separation, centrifugation, sand filtration, membrane separation is performed. The SS agglomeration state varies depending on pH, coagulant dosage, stirring conditions, etc. If the agglomeration treatment is not performed under appropriate conditions, the quality of the water to be treated will be deteriorated and the solid-liquid separation treatment in the next step will be adversely affected May affect.

  In such agglomeration treatment, there is a method of setting agglomeration conditions in laboratory tests. However, in actual agglomeration treatment, if it takes time to set the agglomeration conditions, the quality of the water to be treated fluctuates. There are cases where it cannot be accurately grasped. Therefore, in order to set the optimum aggregation conditions such as pH, coagulant dosage, and stirring conditions, it is important to monitor the treatment state of the treated water during the aggregation process in real time and monitor the SS aggregation state. .

  Regarding this coagulation monitoring, the treated water is irradiated with laser light to receive the scattered light from the particles in the treated water, and AM (Amplitude Modulation) detection is performed on the received light signal, and then the minimum value of the signal intensity It is known that the flocculant dosage is calculated from this minimum value (for example, Patent Document 1). In this aggregation monitoring, the minimum value of the signal intensity of the scattered light is obtained, and the scattered light from the unaggregated suspension is detected from the scattered light from the aggregate in the water to be treated.

As for the laser light used for the aggregation monitoring, it is known to use laser light that emits light at predetermined time intervals by intermittently driving a laser diode (for example, Patent Document 2). The use time of the laser light emitting element is extended by the light emission mode for shortening the light emission time.

JP 2002-195947 A JP 2005-241338 A

  By the way, in the agglomeration treatment of the water to be treated, for example, when the concentration of SS contained is low, the concentration of sludge that is not taken into the flocs in the gap between the agglomerated flocs (floc) is measured, and based on this measured value A chemical injection system for controlling the chemical injection amount of the flocculant is used. In this concentration measurement, laser light is irradiated to the measurement area of the water to be treated, the scattered light from the measurement area is received, and the measurement value representing the unaggregated SS concentration is obtained from the signal level obtained by photoelectric conversion of the scattered light. .

  Further, in the condensing process in the case where the SS concentration of the water to be treated is medium, for example, it may be difficult to measure the SS concentration because flocs are always present in the measurement region. A technique of calculating an aggregation index with reference to a detection value is used.

  However, there is a limit to the sludge concentration to be applied to the agglomeration treatment system by chemical injection. For example, if the SS concentration of water to be treated is very high, for example, excessive sludge is contained, even if laser light is emitted into the water to be treated, scattered light Is blocked by sludge and cannot receive light. That is, laser light emitted toward the measurement area is attenuated by flocs and sludge existing in the space from the light emitting surface to the measurement area, and is also shielded by flocs and sludge existing in the area from the measurement area to the light receiving surface. End up. As a result, the chance that the scattered light reaches the light receiving portion is extremely reduced, so that there is a problem that the concentration of SS cannot be grasped and an index for judging the aggregation state cannot be calculated. If this index cannot be calculated, there is a problem that an appropriate injection amount of the flocculant cannot be determined.

  With respect to such a problem, Patent Documents 1 and 2 do not disclose or suggest the problem, and do not disclose or suggest a configuration for solving the problem.

  Then, the objective of this invention is providing the aggregation monitoring apparatus or the aggregation monitoring method which can measure an aggregation state in the aggregation process of the to-be-processed water with high SS density | concentration in view of the said subject.

Another object of the present invention is to realize an agglomeration system that can perform chemical injection control in treated water that is difficult to receive scattered light by using the above-described agglomeration monitoring device or agglomeration monitoring method. is there.

  In order to achieve the above object, according to one aspect of the coagulation monitoring apparatus of the present invention, the coagulation monitoring apparatus monitors the treatment state of the treated water to be coagulated, and the measurement light is applied to the measurement area of the treated water. A measurement light irradiating unit for irradiating; a scattered light receiving unit for receiving scattered light from particles of the water to be treated in the measurement region; and a received light level of the scattered light for each aggregation process obtained in the scattered light receiving unit. What is necessary is just to provide the measured value calculating part which calculates | requires the parameter | index of the aggregation state of the said to-be-processed water from a change.

  In the aggregation monitoring device, the measurement value calculation unit obtains a change in the light reception level using a peak value of the received light signal of the scattered light and the number of appearances of the received light signal having a peak value equal to or greater than a predetermined value. The aggregation index of the water to be treated may be obtained.

  In the aggregation monitoring apparatus, the measurement value calculation unit sets a first threshold value that defines a peak value of the received light signal and a second threshold value that defines the number of appearance of the peak value that satisfies the first threshold value. The aggregation state of the water to be treated may be determined based on the first threshold value and the second threshold value.

  In the aggregation monitoring device, the water to be treated may be in a state in which the scattered light receiving unit cannot receive the scattered light or in a state in which the received light level is a predetermined level or less at the start of the aggregation treatment.

  In order to achieve the above object, according to one aspect of the coagulation monitoring method of the present invention, the coagulation monitoring method monitors the treatment state of the water to be treated to be coagulated. A measuring light irradiation step for irradiating; a scattered light receiving step for receiving scattered light due to particles of the water to be treated in the measurement region; and a step for measuring a change in a received light level of a received light signal due to the received scattered light; A measurement value calculation step for obtaining an index of the aggregation state of the water to be treated from the change in the light receiving level for each aggregation treatment.

In order to achieve the above object, according to one aspect of the flocculation system of the present invention, there is provided a flocculation treatment system that performs flocculation treatment of water to be treated. A coagulation monitoring device for monitoring a coagulation state; and a chemical injection means for injecting a drug based on a monitoring result of the coagulation monitoring device with respect to the water to be treated. A coagulation monitoring device for monitoring a processing state, a measurement light irradiating unit for irradiating measurement water with measurement light, and a scattered light receiving unit for receiving scattered light from particles of the water to be processed in the measurement region And a measurement value calculation unit for obtaining an indicator of the aggregation state of the water to be treated from a change in the light reception level of the light reception signal for each aggregation process obtained in the scattered light receiving unit, Based on the target, the chemical feed means may control the injection of the drug into the treated water tank.

  According to the present invention, any of the following effects can be obtained.

  <Aggregation monitoring device or aggregation monitoring method>

  (1) Even when the SS concentration is high, the progress of aggregation can be grasped based on the change in the light receiving level of scattered light.

  (2) It is possible to grasp the treatment state of the water to be treated during flocculation in real time. Thereby, it becomes possible to select the dosage of the flocculant according to the processing state.

  (3) By determining the peak value of scattered light above the specified value and the number of occurrences as the received light level of the scattered light, the average aggregation state in the treatment tank can be grasped, and stable control of the aggregation process is performed. Can do.

  <Aggregation system>

  (1) Even if the SS concentration is high, the treatment state of the water to be treated during the coagulation treatment can be grasped in real time, and based on this, the coagulation conditions of the water to be treated and the dosage of the coagulant can be obtained. it can.

  (2) Since the state of floc growth due to the progress of agglomeration according to the change in the light reception level is assumed and the drug injection can be controlled according to the growth state, the cost can be reduced by excessive drug injection.

Other objects, features, and advantages of the present invention will become clearer with reference to the accompanying drawings and each embodiment.

It is a block diagram which shows an example of the aggregation monitoring apparatus which concerns on 1st Embodiment. It is a block diagram which shows an example of an arithmetic circuit. It is a figure which shows the example of a state of the flock in to-be-processed water. It is a figure which shows an example of the detection waveform of the scattered light level according to the growth of floc. It is a figure which shows an example of the detection waveform of the scattered light level according to the growth of floc. It is a figure which shows an example of the detection waveform of the scattered light level according to the growth of floc. It is a flowchart which shows the process sequence of aggregation monitoring. It is a figure which shows an example of the aggregation system which concerns on 2nd Embodiment. It is a flowchart which shows the process sequence of an aggregation process. It is a figure which shows the other structural example of an aggregation monitoring apparatus.

[First Embodiment]

  FIG. 1 shows an aggregation monitoring device according to the first embodiment. The configuration illustrated in FIG. 1 is an example, and the aggregation monitoring device, the aggregation monitoring method, or the aggregation system of the present invention is not limited to such a configuration.

  The aggregation monitoring device 2 is a device that determines the aggregation state of SS in the water to be treated, and includes a sensor unit 4. The coagulation treatment of the water to be treated includes a coagulation process for the purpose of dehydrating excess sludge contained in the water to be treated, in addition to the coagulation sedimentation process for purifying the water to be treated. This sensor unit 4 is, for example, maintained in the water 8 to be treated stored in the coagulation tank 6 and submerged in the sludge that has settled at the bottom of the coagulation tank 6. The coagulation tank 6 is an example of the water tank to be treated for storing the water to be treated 8, and has a function of performing the coagulation treatment of the water to be treated 8. The coagulation tank 6 is, for example, a sedimentation basin (thickener) or the like, in which treated water 8 is stored, and high-concentration sludge is deposited at the bottom.

  The sensor unit 4 includes a laser light irradiation unit 10 and a scattered light receiving unit 12. The laser light irradiation unit 10 is an example of a measurement light irradiation unit that irradiates measurement light used for aggregation monitoring, and is formed at a light exit end of a first optical fiber 14-1 that guides laser light, which is an example of measurement light. Is done. The scattered light receiving unit 12 is formed at the light incident end of the second optical fiber 14-2 that guides the scattered light.

  A measurement region 18 is set between the laser beam irradiation unit 10 and the scattered light receiving unit 12 with a shielding member 16 interposed. The measurement region 18 is irradiated with laser light emitted from the laser light emitting unit 20 from the laser light irradiation unit 10. This measurement region 18 is an example of an irradiation region of the laser water 8 to be treated. Moreover, it is good also as a light emission area | region from the laser light emission surface side of the laser beam irradiation part 10 to the measurement area | region 18. FIG. Furthermore, a region from the scattered light receiving unit 12 until the scattered light generated in the measurement region 18 reaches the light receiving surface may be a light receiving region. When this measurement region 18 is irradiated with laser light, the laser light is scattered by particles in the water 8 to be treated, and scattered light is generated. Therefore, the scattered light receiving unit 12 receives this scattered light from the measurement region 18. In this case, if a floc exists in the measurement region 18, the floc affects the scattered light.

  The shielding member 16 is a means for fixing and supporting the optical fibers 14-1 and 14-2 and a means for shielding natural light from the measurement region 18. In this shielding member 16, as an example, the first support portion 22-1 that fixes and supports the optical fiber 14-1 and the second support portion 22-2 that supports the optical fiber 14-2 have a certain angle. A vertex 24 is provided. For example, the angle of the apex portion 24 is preferably 90 degrees, but may be other angles. The apex portion 24 is opposed to the measurement region 18 and is interposed between the laser light irradiation unit 10 and the scattered light receiving unit 12. Thereby, it is possible to prevent the laser light from the laser light irradiation unit 10 from entering the scattered light receiving unit 12, and the scattered light receiving unit 12 can receive the scattered light on the particle side in the measurement region 18.

  The laser light emitting unit 20 includes, for example, a laser light emitting element 26 and a light emitting circuit 28. The laser light emitting element 26 is an example of a laser light source that emits laser light. The laser light source is preferably a laser diode, but may be any element or device that can obtain laser light. Note that the measurement light used for monitoring aggregation is not limited to laser light. Any light that strikes particles and generates scattered light can be used for monitoring aggregation, and the measurement region 18 can be efficiently irradiated with light by using measurement light having excellent directivity such as laser light. it can. In the case of using such measurement light, a light emitting unit including a light emitting element that emits measurement light and a light emitting circuit that drives the light emitting element may be used. For example, a light emitting diode may be used as the measurement light.

  The light emitting circuit 28 is an example of a driving unit for the laser light emitting element 26. As an example, the light emitting circuit 28 includes an AM (Amplitude Modulation) modulation circuit 30, a timing circuit 32, and a function generator 34. The AM modulation circuit 30 performs amplitude modulation (AM modulation) on the timing signal Ts with a modulation signal Ms having a predetermined frequency f, and outputs a light emission signal Dr having an amplitude of the predetermined frequency f and intermittent at predetermined time intervals. To do. In response to this light emission signal Dr, the laser light emitting element 26 changes with the modulation signal Ms and repeats light emission and non-light emission at a predetermined time interval according to the timing signal Ts. Thereby, the light emission time of the laser light emitting element 26 for aggregation monitoring is shortened. Even when a light emitting element such as a laser diode having a short light emission lifetime of several thousand hours is used for the laser light emitting element 26, deterioration due to continuous lighting can be prevented, so that the usage time can be extended.

  The timing circuit 32 generates a timing signal Ts. The timing signal Ts may be, for example, a pulse signal that is intermittent at a constant cycle. This timing signal Ts is used as synchronization information for the calculation processing of the aggregation index related to the aggregation of the water 8 to be treated. That is, the timing signal Ts synchronizes the light emission of the laser light emitting element 26 and the calculation processing of the aggregation index.

  The function generator 34 is an example of an oscillator that oscillates the modulation signal Ms. The modulation signal Ms preferably has a frequency f that can avoid the influence of natural light on the laser light. For example, f = 70 to 150 [kHz] may be used. The signal form may be a periodic signal having the same amplitude, and the waveform form may be any of a sine wave, a triangular wave, a rectangular wave, and the like.

  When the measurement region 18 is irradiated with the laser light obtained by the laser light emitting unit 20, the scattered light scattered by the microcolloid particles existing in the measurement region 18 enters the scattered light receiving unit 12. In this case, the fine colloidal particles are unaggregated colloidal particles. The scattered light obtained by the micro colloidal particles has a frequency similar to that of the laser light emitted from the laser light irradiation unit 10 and is intermittent in a constant cycle. Further, the reflected light reflected by the floc existing in the measurement region 18 enters the scattered light receiving unit 12.

  In the treated water 8 having a high SS concentration, in addition to the measurement region 18, sludge and aggregated floc exist on the light emitting region and the light receiving region side. In this case, the laser light emitted from the laser light emitting unit 20 is attenuated or shielded by high concentration SS or floc. In this case, the chance that the scattered light scattered by the non-aggregated colloidal particles present in the measurement region 18 and the reflected light reflected by the floc will reach the scattered light receiving unit 12 side extremely.

  The light reception output of the scattered light receiving unit 12 is guided to the signal processing unit 36 by the optical fiber 14-2. The signal processing unit 36 performs processes such as photoelectric conversion, removal of noise components, a level signal representing the intensity of scattered light, and a measurement value representing the intensity of scattered light from the level signal. As an example, the signal processing unit 36 includes a photoelectric conversion circuit 38 and a detection circuit 40.

  The photoelectric conversion circuit 38 includes a photodetector 42, a band pass filter 44, and an amplifier 46. The photodetector 42 receives the scattered light guided by the optical fiber 14-2 and converts it into an electric signal Ei. The band pass filter 44 cuts a noise component from the electric signal Ei and extracts a signal component of the modulation signal Ms. By setting the cut-off frequency of the bandpass filter 44, unnecessary fluctuation components are removed and the signal component of the modulation signal Ms is output. The amplifier 46 amplifies the signal component of the modulated signal Ms in the scattered light and outputs a light reception signal Eo having an amplitude level corresponding to the scattered light. In the photoelectric conversion circuit 38, a photodiode may be used instead of the photodetector 42, or a high-pass filter may be used instead of the band-pass filter 44. By using these filters, it is possible to cut a DC noise component generated by receiving non-measurement light such as natural light or illumination light.

  The detection circuit 40 detects the output signal Do from the received light signal Eo by AM detection (envelope detection). This output signal Do is an example of a light reception signal and represents the level of the direct current component of the light reception signal Eo. The level of the output signal Do represents the level of light scattered by the particles in the water to be treated containing fine colloidal particles. That is, a noise component that is scattered light other than the fine colloidal particles and a reflection component due to flocs are included.

  The output of the detection circuit 40 is applied to the arithmetic circuit 48. The calculation circuit 48 is an example of a measurement value calculation unit, and includes a wave height detection unit 50 and a comparison unit 52. The arithmetic circuit 48 records the level (signal intensity) of the output signal Do input to the arithmetic circuit 48 in the data recording unit 64 of the memory unit 60 (FIG. 2), and measures the output signal Do by the wave height detection unit 50. Do. The arithmetic circuit 48 determines the aggregation level of the water to be treated using these measurement results, and outputs an aggregation index representing the aggregation level. The aggregation level represented by the aggregation index is represented, for example, by “unaggregated”, “insufficient aggregation”, “currently sufficient”, or “excess”. The arithmetic circuit 48 further includes a light emission control unit 54, and outputs a control signal (timing signal Ts) synchronized with the light emission of the laser light emitting element 26 and the calculation processing of the aggregation index to the timing circuit 32.

  The wave height detection unit 50 includes a function of detecting the amplitude of the received scattered light, the amplitude measurement, and counting the number of appearances of the peak waveform. The wave height detection unit 50 detects an inflection point at the level of the output signal Do recorded in the data recording unit 64, for example, and measures the peak value of the inflection point. By detecting the inflection point, the wave height detection unit 50 detects the generation of the amplitude of the output signal Do. In other words, the wave height detection unit 50 detects the first inflection point where the output signal Do changes from rising to falling and the second inflection point where the output signal Do changes from falling to rising, and the adjacent first inflection point and Generation of amplitude is detected by detecting the second inflection point. The wave height detection unit 50 obtains a level difference between the adjacent first and second inflection points by measuring the peak value, and measures the amplitude of the output signal Do. With these functions, the wave height detection unit 50 can measure the number of appearances of the peak waveform of the output signal Do for each amplitude.

  For example, the comparison unit 52 compares the level of the output signal Do recorded in the data recording unit 64 with a preset threshold value, and counts the number of appearances of peak waveforms that are equal to or greater than the threshold value. The level of the output signal Do of the received scattered light, or the combination of the level of the output signal Do and the number of appearances of the waveform that is equal to or greater than the threshold value is set as the received light level of the scattered light. This threshold value may be switched depending on, for example, the type of water to be treated and sludge, the application, or the coagulation conditions, the type of chemical to be added, and one or more threshold values may be set.

  For example, as shown in FIG. 2, the arithmetic circuit 48 is realized by a circuit including a computer such as a microprocessor. The arithmetic circuit 48 includes an analog / digital converter (A / D) 56, a processor 58, and a memory unit 60. The A / D 56 converts the output signal Do into a digital signal. The output signal of the A / D 56 represents the level of the output signal Do as a digital value and is used for digital processing of the amplitude detector 50 and the minimum value detector 52.

  The processor 58 executes an OS (Operating System) and an aggregation program in the program storage unit 62 of the memory unit 60, and functions as the wave height detection unit 50, the comparison unit 52, and the light emission control unit 54 described above.

  The memory unit 60 is an example of a recording unit, and includes a program storage unit 62, a data recording unit 64, and a RAM (Random-Access Memory) 66. The program storage unit 62 stores an OS, the above-described aggregation program, and the like as programs. In addition to the level of the output signal Do, the data recording unit 64 records threshold value data that defines the peak value set according to the aggregation condition and the number of appearances as described above. The RAM 66 is used as a work area for information processing.

  The calculation result of the processor 58 is output to the display unit 67. For example, a liquid crystal display (LCD) is used for the display unit 67. The display unit 67 displays the measurement value used for the calculation of the processor 58, the value of the peak value of the output signal Do as the calculation result, the number of appearances for each threshold, and the determined aggregation index.

  <Relationship between change in received light level and aggregation state>

  The relationship between the aggregation state in the treated water having a high SS concentration and the change in the light reception level of the scattered light detected by the aggregation monitoring device 2 will be described.

  FIG. 3 shows an example of the state of suspended matter and floc contained in the water to be treated or the precipitated sludge.

  In the treated water 8 or sludge having a high SS concentration, when the agglomeration treatment is not sufficiently advanced, unagglomerated suspended matter and floc 70 having a certain size or less are in a dense state. In the water 8 and sludge with insufficient aggregation, the laser light emitted from the laser light irradiation unit 10 hits the flock 70 before reaching the measurement region 18, and the light scattered in the measurement region 18 is received by the laser light. The light is shielded by other flocs 70 and sludge before entering the portion 12. Thus, the clearance gap between the flocs 70 of the to-be-processed water in which the flocks 70 are in a dense state is analyzed.

With regard to the high-concentration treated water in which the flocs 70 having a particle diameter 2a are densely packed, for example, a virtual cubic space is assumed by connecting the centers of four adjacent specific flocs 70, and the flocs 70 occupy in this space. Calculate the percentage. For the ratio of voids surrounded by spheres created by adjacent spheres, refer to the following document, for example.
(Niigata University Faculty of Engineering, Particulate Materials Engineering Laboratory, Professor: Yukio Kimura, Lecture: “Space of Circle and Sphere” http://www.gs.niigata-u.ac.jp/~kimlab/lecture/math/SpacingCirclesSpheres.html )
It can be assumed that the inside of this cube includes four flocks 70 by combining the flocks 70 divided by the sides of the cube. Here, since the particle size of the floc 70 is 2a, the ratio of the sphere to the total volume of the sphere and the volume of the cube is about 0.74, and the ratio of the space (void) is 0.26. The sphere diameter does not affect the ratio of this space.

In addition, since one side of the assumed cube has a diagonal length of 4a, the length of one side is a. Thus, if the volume of the gap in the cube is Vc,
Vc = 16 × 0.26 = 5.88a ³ (1)
It becomes.

As a result, assuming that the particle size of the sludge is increased from 0.2 [mm] to 2 [mm] by injecting the flocculant, the volume of the gap in each particle size is as follows. The flocculant only needs to have a function of aggregating SS in the water to be treated to form a floc, and may be a dehydrating agent for aggregating sludge in the water to be treated and reducing the water content.
(When the particle size is 0.2 mm) V _0.2 = 0.047 [mm ³ ] (2)
(When the particle size is 2 mm) V ₂ = 47 [mm ³ ] (3)
If the total volume of the measurement region 18 and the surrounding light emitting region and light receiving region is, for example, about 3 [mm ³ ], the gap becomes larger due to the growth of the floc 70, so that there is a high possibility that scattered light will pass through this gap. Become.

  [Reception state of scattered light according to floc growth]

  The detection state of the scattered light shown in FIG. 4 shows, for example, a state where the water to be treated is not aggregated or the amount of the flocculant added is small. At this time, since the coagulation treatment in the water to be treated is insufficient, the scattered light scattered by the measurement region 18 in the scattered light receiving unit 12 cannot be received, or the scattered light is attenuated, and the scattered light level is reduced. Is maintained at 0 [mV] or a value close thereto.

  The scattered light detection state shown in FIG. 5 shows a case in which, for example, the aggregation process has progressed and the floc 70 has grown to a predetermined size. The scattered light level increases and the number of received light increases. The floc 70 grown at this time has an increased laser light irradiation area, for example, so that the level of scattered light generated by hitting the surface of the floc 70 increases, and the increase in the floc 70 increases the gap between the flocs 70. There will be more opportunities for higher levels of scattered light. Conversely, if the floc 70 is small and has a high density, the surface area of the floc 70 irradiated with the scattered light is reduced, so that the level of the scattered light is reduced, and the gap between the flocks 70 is reduced, thereby causing the scattered light receiving unit. By the time it reaches 12, the attenuation rate of scattered light increases and the received light level decreases.

  In the scattered light detection state shown in FIG. 6, for example, the aggregating process further proceeds from the aggregating process shown in FIG. 5 and the aggregating process proceeds. The scattered light level further increases and the number of received light increases. . At this time, the peak value of the scattered light level becomes a large value, and the number of appearances of the high scattered light level increases. Since many high scattered light levels can be detected in the water to be treated 8 having a high SS concentration, it is determined that the flocs in the water to be treated 8 are sufficiently grown and the agglomeration process is proceeding. When such a high scattered light level can be received, the drug injection may be stopped.

<Output of aggregation index>

  The laser light emitted from the laser light emitting unit 20 hits the floc 70 existing on the optical path, for example, and generates scattered light. Assuming that the average particle density from the scattered light generation point to the scattered light receiving unit 12 is substantially constant, when the floc density is high (when the floc is small), the scattered light changes in the distance between the particle and the light emitting surface. And the level of the output signal Do is smaller than when the large flock 70 is generated. On the contrary, when the floc 70 is large, the change in the distance between the particle and the light emitting surface is large, and the level of the output signal Do is large compared to the case of the small floc 70.

  The index of the aggregation level when the sludge concentration in the water to be treated 8 is high is based on whether the peak value is equal to or higher than a predetermined threshold depending on the level of scattered light detected and the number of appearances of the level higher than the threshold. Is set. In other words, in this aggregation monitoring, the amount of increase in the received light signal of scattered light and the number of occurrences (occurrence frequency) of such a signal correlate with the increase in the gap between flocs grown by aggregation, which is used as an aggregation index. . Table 1 shows the aggregation index based on the peak value of the scattered light level and the number of appearances thereof.

  In Table 1, L1 to L3 are examples of the first threshold value with respect to the peak value (peak value) of the output signal Do indicating the scattered light level. For example, L1 = 500 [mV], L2 = 1000 [mV], L3 = 2000 [mV] is set. What is necessary is just to set a threshold value with the threshold value of such L1-L3, for example according to the kind of coagulation sludge in to-be-processed water, a property, coagulation conditions, etc. Usually, the threshold value of the peak value is set as a value of L1 <L2 <L3. In the determination of the aggregation level, for each of the threshold values L1 to L3 with respect to the peak value, the number of appearances of the waveform exceeding the threshold value in the aggregation state detection time is determined. N1 to N3 are set as the second threshold regarding the number of appearances, and N1 = 5 [times], N2 = 4 [times], and N3 = 3 [times] are set as an example. For example, the thresholds N1 to N3 of the number of appearances are used to determine the aggregation level by excluding a state where the aggregation state is partially progressing in the water to be treated.

  According to Table 1, for example, it is determined whether or not the peak value of the level (scattered light level) of the output signal Do is greater than or equal to the thresholds L1 to L3, and whether or not the number of appearances satisfies the thresholds N1 to N3 This is an index for determining which of the aggregation levels 1 to 3 belongs to the aggregation state. And based on this parameter | index, it can grasp | ascertain whether the addition amount of a flocculant is inadequate or excess, and addition control can be performed.

<Signal processing and signal processing of measurement values>

  Here, an example of signal processing used for monitoring processing will be described. The timing signal Ts controlled by the timing circuit 32 is a pulse signal having a constant pulse width tw at intervals (cycles) of a constant time T. In this case, the H level section (= pulse width tw) is the laser light emission time, and the L level section (= T-tw) is the laser light non-light emission time. As an example, T = 2 [seconds] and tw = 0.2 [seconds] are set. In this case, T-tw = 2 [seconds] may be set.

  The modulation signal Ms processed by the function generator 34 is a periodic signal having a constant frequency f and the same amplitude. The frequency f may be selected from 70 to 150 [kHz].

  The light emission signal Dr is an output signal of the AM modulation circuit 30 that modulates the timing signal Ts with the modulation signal Ms. That is, the light emission signal Dr is a periodic signal in which the modulation signal Ms is superimposed on the pulse width tw in the H level section of the timing signal Ts. That is, the light emission signal Dr is a periodic signal whose pulse width tw changes with the amplitude of the modulation signal Ms and is intermittent with the timing signal Ts.

  When such a light emission signal Dr is used, laser light having a light emission mode based on the light emission signal Dr can be obtained from the laser light emitting element 26.

  When this laser beam is irradiated from the laser beam irradiation unit 10 to the measurement region 18, scattered light is obtained from suspended substances in the treated water 8 staying in the measurement region 18 and particles such as the floc 70. This scattered light is received by the scattered light receiver 12.

  The light receiving signal Eo is obtained on the output side of the amplifier 46 through photoelectric conversion, filtering and amplification of the photoelectric conversion circuit 38. The light reception signal Eo is intermittent with the timing signal Ts, has the frequency of the modulation signal Ms, and has a level of amplitude corresponding to the intensity of the scattered light.

  When this light reception signal Eo is detected by the detection circuit 40, an output signal Do having a DC level corresponding to the intensity of the scattered light is obtained intermittently with the timing signal Ts. In the signal processing of the light reception signal Eo, for example, the output signal Do can be obtained by detecting the output of the bandpass filter 44 by half-wave rectification and then holding the top peak of the detection output.

  As a result, the arithmetic circuit 48 performs A / D conversion from the output signal Do and measures the peak values of the amplitude and signal level described above.

<Procedure for aggregation monitoring>

  FIG. 7 shows an example of the processing procedure of aggregation monitoring. This processing procedure is an example of the aggregation monitoring method of the present invention. This processing procedure is executed by a computing process (information processing) including the processor 58 and the memory unit 60 included in the arithmetic circuit 48.

  In this processing procedure, conditions for aggregation monitoring are set in the condition setting step (S1). In this condition setting, for example, the SS concentration condition of the treated water, the condition of the type of the treated water and the treated sludge, the crest values L1 to L3 of the scattered light according to the treated water and the treated sludge, and the threshold of the number of appearances thereof N1 to N3 etc. are set.

  After this condition setting, it is determined whether or not aggregation monitoring is started (S2). When monitoring is started (YES in S2), the process proceeds to the laser emission process to drive the laser emission element 26 (S3), and the process proceeds to the laser beam irradiation process (S4). In the laser beam irradiation process, as described above, the measurement region 18 is irradiated with the laser beam.

  In the scattered light receiving step (S5), as described above, the scattered light is received from the measurement region 18 and converted into a received light signal having a level representing the intensity of the scattered light.

  As a signal processing step, the peak value of the waveform is measured for the scattered light level of the output signal Do, and the number of appearances of the waveform whose peak value exceeds the thresholds L1 to L3 is measured (S6). The peak value detection processing of the output signal Do is arithmetically processed by the arithmetic circuit 48 based on the signal processing of the measurement value already described.

  As the determination process of the aggregation state, it is determined whether or not the scattered light level is less than the condition of the aggregation level 1 shown in Table 1 described above for the measured output signal Do (S7). When the peak value of the scattered light level is less than the threshold value L1 (YES in S7), the scattered light receiving unit 12 has received no or almost no scattered light, and the aggregation process in the water to be treated has not progressed. Then, it is determined that the growth of floc is insufficient, and the aggregation index “unaggregated” is output (S8). Based on such determination, in the aggregating process, control such as increasing the addition rate of the aggregating agent is performed.

  When the scattered light level is not less than the aggregation level 1 (NO in S7), that is, when the peak value of the output signal Do is equal to or greater than the threshold L1 and the number of appearances of the waveform is equal to or greater than the threshold N1, the “aggregation level 1 When “above” is confirmed, it is determined whether or not the condition is less than the aggregation level 2 condition (S9). In this determination, it is determined whether the peak value of the output signal Do is the threshold value L2 and whether the number of appearances of such a waveform exceeds the threshold value N2. When the condition of aggregation level 2 is not satisfied (YES in S9), the aggregation index “aggregation level 1 or more and less than 2” is output (S10). Based on this determination, in the flocculation process, it is determined that the flocculation is insufficient or the growth process is flocked, and control is performed to increase the addition amount of the flocculating agent smaller than the flocculation level 1 or less.

  When the scattered light level is not less than the aggregation level 2 (NO in S9). It is determined whether or not the aggregation level is less than 3 (S11). In this determination, it is determined whether the peak value of the output signal Do is the threshold value L3, or whether the number of appearances of such a waveform exceeds the threshold value N3. When the condition of the aggregation level 3 is not satisfied (YES in S11), the aggregation index “aggregation level 2 or more and less than 3” is output (S12). Based on this determination, the aggregation process determines that the aggregation is sufficient, and maintains the current amount of the flocculant charged.

  If the condition of aggregation level 3 is satisfied (NO in S11), the aggregation index “excess drug injection” is output (S13). In this case, in the flocculation process, control for reducing the addition amount of the flocculating agent is performed.

  In this aggregation monitoring process, the determination of the aggregation state is determined from the aggregation level 1 in which a threshold with a low scattered light level is set. However, the present invention is not limited to this, and the output signal Do may be determined from the aggregation level 3. .

<Operation and Effect of First Embodiment>

  According to the first embodiment, the following operations and effects can be obtained.

  (1) The aggregation monitoring device 2 obtains the peak value of the signal waveform from the output signal Do of the received scattered light in the wave height detection unit 50 and the comparison unit 52 of the arithmetic circuit 48, and the peak value exceeds a threshold value. The change in the light reception level is determined by obtaining the number of appearances of the waveform exceeding the threshold. And the arithmetic circuit 48 calculates | requires the parameter | index of the aggregation state of to-be-processed water from the change of this received light level. With such a configuration, even when the SS concentration is high and it is difficult to measure the SS concentration by laser light in a non-aggregated state, the progress of the agglomeration process by the chemical injection can be grasped, and an appropriate chemical injection process is performed. It becomes possible to control the aggregation by.

  (2) In aggregation monitoring, a plurality of threshold values for the peak value of the output signal Do are set, and the change in the light reception level is determined based on which threshold value is exceeded and the number of waveforms that exceed this threshold value. to decide. This threshold value is set according to the nature of the sludge to be treated and the purpose of coagulation contained in the water to be treated, or the type of coagulant added. Thereby, also in the to-be-processed water with high SS density | concentration, an aggregation state can be grasped | ascertained precisely.

  (3) In the determination of the aggregation state, not only the threshold value for the peak value of the output signal Do but also the aggregation level is determined by combining the number of appearances of waveforms exceeding the threshold value, so that the aggregation process is partially performed in the treated water. Therefore, it is possible to eliminate such a state that is unevenly generated.

  (4) In the above embodiment, the aggregation level is determined by the number of appearances of the waveform exceeding the second threshold, but the present invention is not limited to this. When the number of occurrences of the peak value of the output signal Do is small, or when a peak value that partially protrudes occurs, even if the number of appearances of the waveform is not judged or the second threshold value is not exceeded, The aggregation level may be determined only from the peak value. As a result, the gap between the flocs increases due to the large growth of the flocs, and even when the level of the scattered light is biased, it is possible to appropriately control the medicine injection and grasp the aggregation state.

[Second Embodiment]

  FIG. 8 shows the aggregation system according to the second embodiment. The aggregation system 72 is an example of an aggregation processing system using the aggregation monitoring device 2 according to the first embodiment. In FIG. 8, the same parts as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  In the aggregation monitoring device 2, the aggregation index of the water to be treated 8 in which the aggregation treatment is performed in the aggregation tank 6 is calculated and provided to the control unit 74. This agglomeration index indicates an agglomeration index obtained from the treatment state of the water to be treated 8 that is agglomerated in the agglomeration tank 6.

  The controller 74 controls the agglomeration treatment of the water 8 to be treated in the agglomeration tank 6 such as the amount of the flocculant injected and the stirring control. A flocculant is injected into the water 8 to be treated in the flocculation tank 6 from the chemical injection section 76. The agglomeration tank 6 may be provided with a stirrer that stirs the water 8 to be treated. This stirrer may be driven by the drive unit 80 controlled by the control unit 74.

  The control unit 74 is configured by a computer, for example, and calculates the dosage of the flocculant using the aggregation index provided from the aggregation monitoring device 2.

<Aggregating treatment of aggregating system>

  FIG. 9 shows an example of the processing procedure of the aggregation processing. In this processing procedure, it is determined whether or not the aggregation process is started (S21), and the aggregation process is started according to the determination result. When the coagulation process is started (YES in S21), coagulation monitoring is performed on the treatment state of the water 8 to be treated in the coagulation tank 6 (S22). This aggregation monitoring is performed by the aggregation monitoring device 2. Details of this processing content are omitted. In this aggregation monitoring device 2, an aggregation index indicating the treatment state of the water to be treated 8 is calculated (S 23) and provided to the control unit 74 of the aggregation system 72.

  When receiving the aggregation index, the control unit 74 selects the aggregating agent dosage based on the aggregation index (S24). Thereby, the chemical injection of the flocculant is performed from the chemical injection part 76 (S25).

  It is monitored whether or not the aggregation process is terminated (S26). If the aggregation process is not terminated (NO in S26), the process returns to S22 and the aggregation processes of S22 to S26 are continued.

  When the aggregation process is terminated (YES in S26), the aggregation monitoring is terminated (S27), and the aggregation process is terminated.

<Operation and Effect of Second Embodiment>

  According to the second embodiment, the following functions and effects can be obtained.

  (1) The state of agglomeration processing is grasped in real time, and an aggregation index is generated from the measured value of scattered light regardless of the presence or absence of flocs and used for drug injection control, so stable drug injection control can be realized. .

  (2) Coagulation conditions of the water to be treated and the dosage of coagulant are required.

  (3) In addition to optimizing the amount of chemicals to be treated, stable agglomeration can be performed and the agglomeration efficiency can be increased.

  (4) The compensation function of the agglomeration system based on the measurement of the treatment state of the agglomeration tank 6 can be maintained, and the influence on the environmental load can be avoided by preventing the administration of excessive aggregating agent, and the agglomeration process with high reliability Can be realized.

  (5) Even in the case of high-concentration sludge treatment, it is possible to grasp the change in the agglomeration state due to the added chemical and to perform accurate chemical injection control.

[Other Embodiments]

  (1) In the above embodiment, laser light that is emitted at a predetermined time interval and amplitude-modulated at a predetermined frequency is used, but turbidity is measured without considering the life of the laser light-emitting element. In the case of priority, laser light that has been subjected to amplitude modulation at a predetermined frequency may be used. In this case, a plurality of lowest level signals may be extracted from the continuous light reception signal at a predetermined timing.

  (2) In the above embodiment, as the aggregation state index, the peak value of the output signal Do, which is the scattered light level, is equal to or greater than a threshold value, and the aggregation level is determined based on a change in the number of appearances of waveforms exceeding the threshold value However, the present invention is not limited to this. For example, the arithmetic circuit 48 may calculate the total of the output signals Do of the measured scattered light level and compare the total value with a predetermined threshold value to obtain the aggregation level index. The arithmetic circuit 48 includes, for example, an integration circuit, and may calculate the total value from the measured waveform of the output signal Do, or may calculate the total value using the peak value recorded in the data recording unit 64. Also good. The calculation circuit 46 may be set with an aggregation level index based on the total value of the scattered light levels in a predetermined measurement time.

  (3) Further, the arithmetic circuit 48 may calculate an average value of the output signal Do at a predetermined determination time with respect to the measurement result of the output signal Do at the scattered light level, for example. In the determination of the aggregation state, a threshold value that associates the average value with the aggregation level may be used.

  (4) In the above embodiment, the bandpass filter 44 and the amplifier 46 may be realized by digital processing.

  (5) In the above embodiment, purified water, industrial water, waste water, etc. are exemplified as the treated water 8 whose treatment state is monitored by the aggregation monitoring device 2, but this treated water 8 is discarded from a quarry or the like. It may be a drinking liquid such as highly concentrated inorganic wastewater or fruit juice.

  (6) The determination of the aggregation state is not limited to the determination of the aggregation state only once, for example, the scattered light level is measured a plurality of times at predetermined intervals, and the waveform exceeding the threshold value of the measured output signal Do The total number of peak values or the average number of occurrences may be used. Alternatively, the elapsed time after the chemical injection process is measured, and the change in the received light level of the scattered light due to the difference in the elapsed time may be combined to determine the aggregation state index.

  (7) In addition, the aggregation monitoring device 2 is not limited to the case of determining the aggregation state from only the measured output signal Do, and for example, uses the data of the output signal Do of the previous or previous time stored in the data recording unit 64. Thus, the aggregation state may be determined. For example, the arithmetic circuit 48 may obtain a difference value from the value of the output signal Do determined immediately before together with the value of the output signal Do measured this time, and may set the aggregation level index in consideration of the change amount.

  (8) In the above embodiment, the aggregation level is determined based on the peak value of the output signal Do exceeding the threshold and the number of appearances thereof, but the present invention is not limited to this. The arithmetic circuit 48 may set and determine the aggregation level index even when only the number of appearances of the output signal Do exceeding the threshold value increases or decreases, for example.

  (9) As shown in FIG. 10, for example, the aggregation monitoring device 2 includes filter members 80 and 82 on the front side of the laser light emitting element 26 and the photodetector 42 which is a light receiving unit for scattered light. You may provide the washing | cleaning apparatus 90 which carries out the cleaning process of 80,82 one surface. The filter members 80 and 82 are an example of protective means that prevents the water to be treated or sludge from coming into contact with the laser light-emitting element 26 or the photodetector 42, and are transparent members that do not hinder the transmission of laser light or its scattered light, such as acrylic or glass. What is necessary is just to be formed. The cleaning device 90 includes, for example, nozzles 92 and 94 for spraying water, air, and other cleaning agents that do not affect the water to be treated 8 and sludge to the filter members 80 and 82. The cleaning device 90 may be spaced apart from the measurement region 18 of the water to be treated 8 and spaced apart so as not to affect the monitoring of the water to be treated 8. Further, the cleaning device 90 is connected to, for example, the light emission control unit 54 in the arithmetic circuit 48 of the aggregation monitoring device 2 or the control unit 74 of the aggregation system 72 so that it does not overlap with the light emission timing of the laser light, the chemical injection processing timing, or the like. In addition, operation control may be performed. According to such a configuration, the light emitting part of the laser light and the light receiving part of the scattered light can always be kept clean and agglomerated without being affected by sludge in the water to be treated 8 having a high SS concentration. The state can be grasped.

  (10) The aggregation monitoring device 2 performs a measurement process of the aggregation state of the water to be treated 8 before the addition of the flocculant at the start of the aggregation process, and cannot detect the light reception level of the scattered light in an unaggregated state. Alternatively, it may be determined that only a very small value is detected. That is, since the method for determining the aggregation state shown in the above embodiment assumes that the SS concentration is extremely high, the conventional aggregation monitoring of the unaggregated SS concentration cannot be performed at the start of the aggregation processing. You may perform the process to confirm.

As described above, the most preferable embodiment of the aggregation monitoring device, the aggregation monitoring method, and the aggregation system of the present invention has been described. The present invention is not limited to the above description. It goes without saying that various modifications and changes can be made by those skilled in the art based on the gist of the invention described in the claims or disclosed in the embodiments for carrying out the invention. It goes without saying that such modifications and changes are included in the scope of the present invention.

ADVANTAGE OF THE INVENTION According to this invention, the process condition of the coagulation process of to-be-processed water, such as purified water, industrial water, and waste_water | drain, can be grasped | ascertained accurately and can contribute to an efficient coagulation process.

DESCRIPTION OF SYMBOLS 2 Aggregation monitoring apparatus 4 Sensor part 6 Aggregation tank 8 Water to be treated 10 Laser light irradiation part 12 Scattered light receiving part 14-1 1st optical fiber 14-2 2nd optical fiber 16 Shielding member 18 Measurement area | region 20 Laser light emission Unit 22-1 first support unit 22-2 second support unit 24 apex angle unit 26 laser light emitting element 28 light emitting circuit 30 AM modulation circuit 32 timing circuit 34 function generator 36 signal processing unit 38 photoelectric conversion circuit 40 detection circuit 42 Photodetector 44 Band pass filter 46 Amplifier 48 Arithmetic circuit 50 Wave height detection unit 52 Comparison unit 54 Light emission control unit 56 A / D
58 processor 60 memory unit 62 program storage unit 64 data recording unit 66 RAM
70 Flock 72 Aggregation System 74 Control Unit 76 Chemical Injection Unit 80, 82 Filter Member 90 Cleaning Device 92, 94 Nozzle

Claims (6)

A coagulation monitoring device for monitoring the treatment state of the water to be coagulated,
A measurement light irradiating unit for irradiating the measurement area with the measurement light; and
A scattered light receiving unit that receives scattered light from particles of the water to be treated in the measurement region;
A measurement value calculation unit for obtaining an indicator of the aggregation state of the water to be treated from a change in the light reception level of the scattered light for each aggregation process obtained in the scattered light receiving unit;
An agglomeration monitoring device comprising:   The measurement value calculation unit obtains a change in the received light level using a peak value of the received light signal of the scattered light received and the number of appearances of the received light signal having a peak value equal to or greater than a predetermined value, and the treated water The aggregation monitoring apparatus according to claim 1, wherein an aggregation index is obtained.   The measurement value calculation unit sets a first threshold value that defines a peak value of the received light signal, and a second threshold value that defines the number of occurrences of a peak value that satisfies the first threshold value, and the first threshold value The coagulation monitoring apparatus according to claim 2, wherein the coagulation state of the water to be treated is determined based on the second threshold value.   The said to-be-processed water is the state which the said scattered light light-receiving part cannot receive the said scattered light at the time of the start of the said aggregation process, or the said light reception level is a state below a predetermined level, It is characterized by the above-mentioned. The aggregation monitoring apparatus according to any one of the above. A coagulation monitoring method for monitoring the treatment state of water to be coagulated,
A measurement light irradiation step of irradiating the measurement area with the measurement light; and
A scattered light receiving step for receiving scattered light from particles of the water to be treated in the measurement region;
Measuring the change in the light receiving level of the received light signal due to the scattered light received;
A measurement value calculation step for obtaining an indicator of the aggregation state of the water to be treated from the change in the light reception level for each aggregation treatment;
A method for monitoring aggregation. A coagulation treatment system for coagulating water to be treated,
A treated water tank for storing the treated water;
A coagulation monitoring device for monitoring the coagulation state of the water to be treated;
A chemical injection means for injecting a medicine based on a monitoring result of the aggregation monitoring device for the treated water;
The aggregation monitoring device comprises:
A coagulation monitoring device for monitoring the treatment state of the water to be coagulated,
A measurement light irradiating unit for irradiating the measurement area with the measurement light; and
A scattered light receiving unit that receives scattered light from particles of water to be treated in the measurement region;
A measurement value calculation unit for obtaining an indicator of the aggregation state of the water to be treated from a change in the light reception level of the light reception signal for each aggregation process obtained in the scattered light receiving unit;
And the chemical injection means controls the injection of the chemical into the water tank to be treated based on the aggregation state index.

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