JP2021178262A - Electrophoretic speed measurement method, electrophoretic speed measurement device, aggregation control device, program and aggregation control system - Google Patents

Abstract

To provide an electrophoretic speed measurement method that can continuously, stably and accurately measure an electrophoretic speed of impurities in the water to which a voltage is applied.SOLUTION: An electrophoretic speed measurement method includes a moving speed measurement step, a correction value acquisition step, and a correction step. The moving speed measurement step measures a moving speed of impurities contained in treated water to which a voltage is applied. The correction value acquisition step acquires a correction value for correcting the moving speed. The correction step corrects the moving speed using the correction value, and outputs the corrected moving speed as the electrophoretic speed of the impurities contained in the treated water.SELECTED DRAWING: Figure 1

Description

Embodiments of the present invention relate to a method for measuring the speed of electrophoresis, a speed measuring device for electrophoresis, an aggregation control device, a program, and an aggregation control system.

Conventionally, as a method for treating water to be treated such as river water, rainwater, sewage, and industrial wastewater, a method of using a coagulant to form impurities contained in the water to be treated as agglomerates (flock) and precipitating and removing them has been used. be. In this method, the aggregated state of flocs affects the quality of the treated water. The floc aggregation state changes depending on the amount of the flocculant injected into the water to be treated. However, the amount of the flocculant injected, which improves the flocculation state, changes with the fluctuation of the water quality of the raw water. Therefore, a method of appropriately controlling the amount of the flocculant injected so that the flocculation state becomes good in response to the fluctuation of the water quality of the water to be treated is being studied.

Conventionally, a method of controlling the agglutinating agent injection amount using the result of observing the flocculation state has not been put into practical use, and the agglutinating agent injection amount is controlled according to the fluctuation of the water quality of the raw water. Normally, in order to control the amount of flocculant injected into the water to be treated so that the flocculation state is good, the flocculation state is evaluated and the result is used to inject the optimum flocculant. It is necessary to calculate the amount.

The charged state of impurities (including flocs) is used as an index for evaluating the aggregated state of flocs.

It has been devised to measure the charged state of impurities by image processing at the rate of electrophoresis of impurities in the water to be treated (suspension) to which a voltage is applied.

Japanese Patent No. 6270655 JP-A-2017-56418 Japanese Unexamined Patent Publication No. 2018-143937

An object to be solved by the present invention is to provide a method for measuring the speed of electrophoresis, which can continuously and stably measure the speed of electrophoresis of impurities in water to which a voltage is applied.

In order to solve the above problems, the method for measuring the speed of electrophoresis of the embodiment includes a moving speed measuring step, a correction value acquisition step, and a correction step. The moving speed measuring step measures the moving speed of impurities contained in the water to be treated to which a voltage is applied. The correction value acquisition step acquires a correction value for correcting the movement speed. In the correction step, the movement speed is corrected using the correction value, and the speed of electrophoresis of impurities contained in the water to be treated is output.

The figure which shows the structure of the water treatment plant which concerns on 1st Embodiment. The figure which shows the cell which contains the suspension which concerns on 1st Embodiment. The flowchart which shows the operation of the aggregation control apparatus which concerns on 1st Embodiment. The figure which shows the trend data at the time of continuously measuring the moving speed of the impurity contained in the water to be treated when the voltage which concerns on 1st Embodiment is applied, and when the voltage is not applied. The figure which shows the cell which contains the suspension which concerns on 2nd Embodiment. The flowchart which shows the operation of the aggregation control apparatus which concerns on 2nd Embodiment. The figure which shows the trend data when the moving speed which concerns on 2nd Embodiment is continuously measured by changing the applied voltage alternately. The figure which shows the coagulant injection amount determined based on the corrected movement speed which concerns on 2nd Embodiment.

Hereinafter, embodiments for carrying out the invention will be described.

(First Embodiment)
The method for measuring the speed of electrophoresis, the speed measuring device for electrophoresis, the aggregation control device, the program, and the aggregation control system according to the first embodiment will be described with reference to FIGS. 1 to 4.

FIG. 1 is a diagram showing a configuration of a water treatment plant 1 according to the first embodiment. The water treatment plant 1 includes a solid-liquid separation step. The solid-liquid separation step is a step of separating solids (impurities) such as suspensions contained in the liquid from the liquid with a flocculant, but is not limited to specific equipment. The water treatment plant 1 is, for example, a water purification plant, a sewage treatment plant, an industrial wastewater treatment facility, or the like. When the water treatment plant 1 is a water purification plant, the raw water is, for example, river water, dam lake water, groundwater, rainwater, and sewage. Hereinafter, the water treatment plant 1 will be described as a water purification plant as an example. The water treatment plant 1 is not limited to a water purification plant, and may be a sewage treatment plant, an industrial wastewater treatment facility, or the like.

For example, the water treatment plant 1 shown in FIG. 1 includes a coagulation control system 2 and each water storage unit as equipment for realizing the solid-liquid separation function. For example, each water storage unit is a landing well 10, a mixing pond 20 (rapid mixing pond), a floc forming pond 30-1 to 30-3, a sedimentation pond 40, and a filtration pond 50. Of each water storage section, the landing well 10 is located most upstream with respect to the flow of the water to be treated. Of each water reservoir, the filtration reservoir 50 is located most downstream with respect to the flow of water to be treated.

The landing well 10 is a facility that stores raw water sent to the water treatment plant 1, separates impurities having a relatively high specific density such as plants and earth and sand from the raw water, and sends the water to the water storage section in the subsequent stage. The raw water referred to here is the water to be treated, and is sent to the landing well 10 from inside and outside the water treatment plant 1. The "water to be treated" is water containing a target substance to be separated by the treatment during the treatment by the water treatment plant 1. Further, the water to be treated includes a part of the water being treated by the water treatment plant 1 and the water collected from the water treatment plant 1. Water that has been treated and is discharged, reused, or drinkable is referred to as "treated water". That is, the raw water can be said to be the water to be treated in the initial state. The water to be treated includes water that is collected from the water treatment plant 1 and then not returned to the water treatment plant 1. Further, the "impurity" referred to here is a target substance to be separated by the treatment by the water treatment plant 1. The "impurities" include those in which impurities are agglomerated with each other by a coagulant described later (flock).

The landing well 10 is provided with a water quality meter 11. The water quality meter 11 measures the water quality of the water to be treated in the landing well 10. For example, water quality is represented by various quantities such as turbidity, chromaticity, water temperature, conductivity, pH (hydrogen ion concentration index), and alkalinity. The water quality meter 11 transmits information representing the water quality obtained by measuring these quantities to the aggregation control system 2. In the landing well 10, relatively large unnecessary substances such as plants and earth and sand are separated from the water to be treated by sedimentation. The supernatant water from which these unnecessary substances have been separated (hereinafter referred to as “supernatant water”) is sent to the mixing pond 20 in the subsequent stage in a state containing the suspension remaining without being separated by precipitation.

A flow meter 12 is provided in the pipe between the landing well 10 and the mixing pond 20. The flow meter 12 measures the flow rate of the supernatant water sent from the landing well 10 to the mixing pond 20. The flow meter 12 transmits information indicating the flow rate of the supernatant water sent from the landing well 10 to the mixing pond 20 to the coagulation control system 2.

The supernatant water is sent from the landing well 10 to the mixing pond 20. The coagulation control system 2 injects a coagulant into the water (mixed water) of the admixture pond 20. For example, the flocculant includes an aluminum-based inorganic flocculant such as poly aluminum chloride (PAC: Poly Aluminum Chloride) and aluminum sulfate (sulfate band). Of these, PAC is mainly used in water purification plants.

The mixing pond 20 is provided with a stirring device 21 and a pH meter 22. The stirring device 21 (rapid stirring device) stirs the water in the mixing pond 20. For example, the stirring device 21 is a flash mixer. A motor is connected to the stirring device 21, and the stirring speed may be variable. The pH meter 22 continuously measures the pH of the water in the mixing pond 20. The pH meter 22 may intermittently measure the pH of the water in the mixing pond 20 at a predetermined cycle. For example, the pH meter 22 measures pH every 10 minutes. The pH meter 22 transmits information representing the pH value of the water in the mixing pond 20 to the aggregation control system 2. The pH meter 22 may be provided in the pipe between the mixing pond 20 and the floc forming pond 30-1 to 30-3. When the flocculant is injected into the mixing pond 20, the suspension (impurity) contained in the water to be treated aggregates and becomes an agglomerate (flock). In the mixing pond 20, the mixing of the raw water and the coagulant is promoted by the stirring device 21. Impurities in the raw water aggregate to form flocs by promoting miscibility between the raw water and the flocculant. The mixing pond 20 sends the treated water in which the raw water and the flocculant are mixed to the floc forming ponds 30-1 to 30-3 together with the formed flocs.

The floc forming ponds 30-1 to 30-3 aggregate the flocs formed in the admixture pond 20 to form larger flocs. The floc forming ponds 30-1 to 30-3 have a slow-speed stirring device 31-1 to 1-31-3 that slowly stirs the treated water.

The slow-speed stirring device 31-1 to 1-31-3 is set so that the stirring intensity gradually decreases toward the downstream side. That is, the rotation speed of the slow-speed stirring device 31-1 to 1-31-3 is highest in the slow-speed stirring device 31-1 and decreases in the order of the slow-speed stirring device 31-2 and the slow-speed stirring device 31-3. As a result, the flocs repeatedly collide with other flocs in the water to be treated, and become huge and easily settle. The floc forming ponds 30-1 to 30-3 send the water to be treated containing the flocs to the settling pond 40.

The settling pond 40 precipitates the flocs contained in the water to be treated by retaining the water to be treated supplied from the floc forming ponds 30-1 to 30-3 for a predetermined time or longer. The predetermined time is, for example, about 3 hours. The sedimentation pond 40 sends the water to be treated, which has been retained for a predetermined time or longer, to the filtration pond 50.

The filtration pond 50 removes minute flocs that have not been settled and removed in the settling pond 40, for example, by sand filtration. The clean water from which the flocs have been removed by the filter pond 50 is sterilized with chlorine in a clean water pond (not shown) and then distributed to a water pipe. The treated water may be appropriately treated with ozone or biological activated carbon before being passed through sand filtration in the filtration pond 50. Further, the treated water may be subjected to the same treatment after being passed through sand filtration.

The coagulation control device 80 includes a velocity measuring device 90, a coagulant injection control unit 83, and a charge state target value calculation unit 84. A part or all of the speed measuring device 90, the flocculant injection control unit 83, and the charge state target value calculation unit 84 are hardware functional units such as LSI (Large Scale Integration) and ASIC (Application Specific Integrated Circuit). You may. The coagulation control device 80 includes a coagulant injection rate set value calculated according to the charge state of impurities (including flocs) that combine electrophoresis and image processing, and a flow rate of water to be treated measured by the flow meter 12. Based on, the amount of flocculant injection is determined. The program may be recorded on a computer-readable recording medium. The computer-readable recording medium is, for example, a flexible disk, a magneto-optical disk, a portable medium such as a ROM or a CD-ROM, or a storage device such as a hard disk built in a computer system. The diagnostic device program may be transmitted over a telecommunication line.

The speed measuring device 90 includes a moving speed measuring unit 81 and a correction unit 82.

The moving speed measuring unit 81 is a device that analyzes a part of the collected water to be treated and measures the agglutination state index value. In the water treatment plant 1 shown in FIG. 1, a configuration in which a part of the water to be treated is collected from the mixing pond 20 is shown. However, this configuration is an example, and the water to be treated does not necessarily have to be collected from the mixing pond 20. For example, the water to be treated may be separated from the distribution pipe between the mixing pond 20 and the floc forming ponds 30-1 to 30-3, or may be obtained from the floc forming ponds 30-1 to 30-3. May be good. Further, the water flow to the moving speed measuring unit 81 may be mechanically collected by a pump or the like, or the operator of the water treatment plant 1 may collect the water to be treated instead of the pump.

The collected water to be treated is contained in a predetermined measuring container (hereinafter referred to as "cell 200"). The water to be treated contains impurities and fine flocs. In the following, the water to be treated is referred to as suspension 300, if necessary. The water to be treated is also referred to as test water or sample, if necessary.

The moving speed measuring unit 81 includes a light source unit 810, an imaging unit 811 and a speed measuring unit 812 as a configuration for measuring the aggregation state index value. The light source unit 810 irradiates the cell 200 with light. The light source unit 810 is a light source that irradiates, for example, laser light or visible light. The light source unit 810 may be configured so that the intensity and wavelength of the emitted light can be changed.

The image pickup unit 811 is configured by using an image pickup device such as a camera. The image pickup unit 811 receives the scattered light that the light emitted from the light source unit 810 is reflected by the surface of the floc in the mixed water to the optical system. The image pickup unit 811 is arranged at a position in the cell 200 where the water to be treated can be imaged. For example, the imaging unit 811 is installed on the side surface of the cell 200 so that the suspension 300 can be imaged through the transparent side surface of the cell 200. As shown in FIG. 2, the image pickup unit 811 images the suspension 300 on the suspension 300 at a predetermined cycle. The predetermined cycle is, for example, a cycle of 1/3 second to 1 second. When the predetermined cycle is a 1/3 second cycle, the image pickup unit 811 generates 3 frames of image data per second. The fine flocs whose surface charge is neutralized move not only in the electric field direction but also in the two-dimensional direction. The image pickup unit 811 outputs the generated image data to the speed measurement unit 812 at each imaging time.

The speed measuring unit 812 performs image analysis processing by software on the image data output from the imaging unit 811 and measures the electrophoresis speed of flocs in the water to be treated. Specifically, the speed measuring unit 812 measures the position of the flocs in the suspension 300 in the image data output from the imaging unit 811 for each floc. The speed measuring unit 812 measures the position of each floc at different imaging times. Here, an arbitrary imaging time is defined as the first imaging time, and the imaging time after a predetermined cycle is defined as the second imaging time. The interval between the first imaging time and the second imaging time is, for example, a 1-second interval or a 1/3 second interval. The speed measuring unit 812 measures the speed of the electrophoresis of the flocs based on the position of the flocs at the first imaging time and the positions of the flocs at the second imaging time. Further, the speed measuring unit 812 may measure the average speed of the electrophoresis of the flocs based on the positions of the flocs at two or more imaging times. The speed measuring unit 812 outputs the measurement data of the measured electrophoresis speed for each floc to the correction unit 82.

The correction unit 82 acquires the measurement data of the electrophoresis speed for each floc output by the speed measurement unit 812. The correction unit 82 calculates the average value of the electrophoresis speed of each floc based on the measurement data of the electrophoresis speed of each floc. Further, the correction unit 82 acquires a correction value for correcting the average value of the electrophoresis speed of each floc. Then, the correction unit 82 corrects the average value of the electrophoresis speed of each floc using the correction value, and outputs it as the electrophoresis speed of impurities (including flocs). The measurement data used when calculating the average value is the measurement data captured in 1 to 5 minutes. Dozens to hundreds of flocs are observed in these 1 to 5 minutes. The correction unit 82 obtains the average value of the electrophoresis speed in one measurement by statistically processing the electrophoresis speed of each floc. The correction unit 82 outputs information representing the average value of the electrophoresis speed corrected by the acquired correction value to the coagulant injection control unit 83.

The charge state target value calculation unit 84 calculates a control target value when the coagulant injection rate of the coagulant injection device 70 is determined by the feedback control method. Feedback control is a control method in which a controlled variable follows a control target value by varying the manipulated variable based on the deviation between the controlled variable and the control target value. The charge state target value calculation unit 84 includes a water quality meter 11 for measuring the water quality of the landing well 10, a pH meter 22 for measuring the water quality of the mixing pond 20, a settling pond water quality meter 41 for measuring the water quality of the settling pond 40, and a filtration pond 50. The target value of the charged state is calculated based on the information from the filtration pond water level meter 51 that measures the water level of. The target value may be manually input by the operator, or the target value may be calculated from information on the raw water quality of the landing well, the treated water quality of the sedimentation pond, and the clogging speed of the filtration pond. When the operator manually inputs the target value, the operator inputs the target value manually from the target value manual input unit 60. The target value manual input unit 60 is, for example, a keyboard, a mouse, a touch panel, or the like. The charge state target value calculation unit 84 outputs the calculated target value to the coagulant injection control unit 83.

The coagulant injection control unit 83 is a coagulant injection device based on the target value calculated by the charge state target value calculation unit 84 and the information representing the average value of the electrophoresis speed calculated by the coagulant injection control unit 83. The amount of the flocculant injected in 70 is determined as the operation amount. For example, the flocculant injection control unit 83 executes feedback control such as P control (proportional control: Proportional Controller), PI control (proportional integral control: Proportional-Integral Controller), and PID control (Proportional-Integral-Differential Controller). .. The coagulant injection control unit 83 outputs the determined coagulant injection amount to the coagulant injection device 70. The coagulant injection amount may be the coagulant injection rate, which is the amount of coagulant injected per treatment flow rate.

The coagulant injection device 70 injects the coagulant into the mixing pond 20 in accordance with the control from the coagulation control device 80.

Next, the aggregated state of flocs will be described.

The floc aggregation state differs depending on the amount of the flocculant injected into the water to be treated. The surface of the suspension is usually negatively charged in water. On the other hand, as the flocculant, one that is positively charged in water is used. Therefore, the flocculant adheres to the suspension (impurities). The flocculant adhering to the suspension brings the surface potential of the suspension closer to 0 [mV] by canceling the negative charge of the suspension. Therefore, the flocculant has the effect of weakening the repulsion between the suspensions and increasing the number of collisions. Due to the action of this flocculant, the flocs that collide with each other gradually agglomerate, and the formation of larger flocs is promoted.

If the coagulant injection amount is insufficient, the average value of the surface potentials of the suspensions remains negatively large and the suspensions repel each other. Therefore, the formation of flocs does not proceed sufficiently when the amount of flocculant injected is insufficient. On the other hand, when the amount of the flocculant injected is excessive, the average value of the surface potentials of the suspensions becomes positive and the suspensions repel each other. Therefore, the formation of flocs does not proceed sufficiently even in a situation where the amount of the flocculant injected is excessive. On the other hand, when the amount of the flocculant injected is appropriate, the surface charge of the suspension is neutralized, the repulsive force between the suspensions is reduced, and the suspensions are mutually affected by the action of the intramolecular force. Inquire. Therefore, the formation of flocs proceeds when the amount of the flocculant injected is appropriate. Therefore, it is desirable that the amount of the flocculant injected is controlled to an appropriate amount that neutralizes the surface charge of the suspension (makes the surface potential approach 0 [mV]).

FIG. 2 is a diagram showing a cell 200 containing the suspension 300 according to the first embodiment. The material of the cell 200 is a transparent material such as glass or acrylic. The cell 200 includes an electrode 210 at the positive end of the x-axis and an electrode 220 at the negative end of the x-axis in the figure. That is, the cell 200 has a pair of electrodes 210 and 220. Further, the electrode 210 and the electrode 220 are arranged so as to face each other in the x-axis direction. The electrode 210 and the electrode 220 are connected to the voltage application unit 230. The voltage application unit 230 applies a voltage between the cathode 210 and the anode 220. In FIG. 2, the negative electrode of the voltage application unit 230 is connected to the electrode 210. Hereinafter, if necessary, the electrode connected to the negative electrode of the voltage application unit 230 is referred to as a cathode. Further, the positive electrode of the voltage application unit 230 is connected to the electrode 220. Hereinafter, if necessary, the electrode connected to the positive electrode of the voltage application unit 230 is referred to as an anode. In FIG. 2, the voltage application unit 230 applies a negative potential to the electrode 210 and a positive potential to the electrode 220. The measured voltage when measuring the moving speed of the floc is, for example, 10 to 40 V. The voltage application time is, for example, 3 to 5 minutes. After applying the voltage for 3-5 minutes, the suspension 300 is replaced. By applying this voltage, the flocs in the positively or negatively charged suspension 300 move in the direction of the electrode 220 or the electrode 210 (electric field direction). Hereinafter, the moving speed in the positive direction of the x-axis is represented by a positive value, and the moving speed in the negative direction of the x-axis is represented by a negative value. Similarly, it is assumed that the moving speed in the positive direction of the y-axis is represented by a positive value, and the moving speed in the negative direction of the y-axis is represented by a negative value. Here, the depth (thickness) of the measuring container (cell) in the Z-axis direction is, for example, 1 mm to 3 mm.

When a voltage is applied to the suspension 300, the fine flocs having a negative surface charge electrophores in the negative direction of the x-axis toward the electrode 220 to which the positive potential is applied. Therefore, the average rate of electrophoresis of flocs in suspension 300, which has a negative surface charge, is negative.

Since the electric field direction according to the measured voltage is approximately the x-axis direction, the electric field direction is hereinafter referred to as the x-axis direction as necessary. Further, since the direction intersecting the electric field direction due to the measured voltage includes the y-axis direction, the direction intersecting the electric field direction due to the measured voltage is referred to as the y-axis direction as necessary thereafter.

When a voltage is applied to the suspension 300, the fine flocs having a positive surface charge electrophores in the positive direction of the x-axis toward the electrode 210 to which the negative potential is applied. Therefore, the average rate of electrophoresis of flocs in suspension 300, which has a positive surface charge, is positive.

The fine flocs whose surface charge is neutralized float in the suspension 300 even when a voltage is applied. Therefore, the direction of electrophoresis of fine flocs whose surface charge is neutralized is not constant even when a voltage is applied between the electrodes 210 and 220. Therefore, the variation in the moving speed of each floc becomes large, and the dispersion of the moving speed becomes large. The dispersion value of the electrophoresis rate of fine flocs whose surface charge is neutralized is equal to or higher than a predetermined value. That is, by using this predetermined value as a threshold value and comparing the dispersion value when a voltage is applied with the threshold value, it is possible to grasp whether or not the surface charge is neutralized.

As described above, the surface charge state (charged state) of the flocs can be obtained by measuring the rate of electrophoresis of the flocs in the suspension 300. However, in the cell 200 for continuously measuring the charge state of the flocs, a phenomenon occurs in which the flocs move immediately after the suspension 300 is sealed in the cell 200 even though no voltage is applied. ..

The cause of this is the generation of a flow due to the impact of closing the encapsulation valve being transmitted to the suspension 300 in the cell 200, and the temperature difference between the water temperature of the suspension 300 and the temperature around the cell 200 in the suspension 300. It is conceivable that convection is generated, and convection of the suspension 300 is generated due to a change in the volume inside the cell 200 due to the accumulation of deposits such as flocs on the inner wall of the glass of the cell 200.

FIG. 3 is a flowchart showing the operation of the aggregation control device 80 according to the first embodiment.

In step S101, the water to be treated (suspension 300) is passed through the cell 200, and the valves before and after the cell 200 are closed. The suspension 300 is a part of the water to be treated collected from the mixing pond 20. The suspension 300 is collected from the mixing pond 20 and passed through the cell 200. Next, the valves around the cell 200 are closed. The work of closing the valves around the cell 200 may be performed mechanically by an electric switch or the like, or may be manually performed by the operator of the water treatment plant 1.

In step S102, a correction value for correcting the moving speed of impurities (including flocs) in the suspension 300 to which the voltage is applied is acquired. The correction value in the first embodiment is that impurities (including flocs) in the suspension 300 to which no voltage is applied are continuously imaged, and individual impurities (including flocs) are imaged in the x-axis direction. And the moving speed in the y-axis direction. That is, the correction value in this embodiment is the moving speed of impurities that does not depend on the applied voltage.

In step S103, the suspension 300 in the cell 200 is drained, and the next suspension 300 is sampled.

In step S104, as in step S101, the suspension 300 is passed through the cell 200, and the valves before and after the cell 200 are closed.

In step S105, a voltage is applied to the suspension 300.

In step S106, the moving speed measuring unit 81 continuously images impurities (including flocs) in the suspension 300 to which the voltage is applied, and individually images the impurities (including flocs) in the suspension 300 to which the voltage is applied by image processing. The rate of electrophoresis of impurities in the x-axis direction and the y-axis direction is measured. In the present embodiment, the moving speed of impurities contained in the water to be treated to which a voltage is applied is the sum of the moving speeds of impurities that do not depend on the applied voltage and the moving speeds of impurities that depend on the applied voltage. It is the moving speed. That is, in the present embodiment, the moving speed of the impurities contained in the water to be treated to which the voltage is applied is a value measured by the moving speed of the impurities contained in the suspension 300 to which the voltage is applied.

In step S107, the correction unit 82 corrects the moving speed using the correction value.

A method of correcting the moving speed in step S107 will be described with reference to FIG.

FIG. 4 shows a continuous measurement of the moving speed of impurities contained in the water to be treated when the voltage according to the first embodiment is applied and when the voltage is not applied (when there is no voltage). It is a figure which shows the trend data of. In particular, FIG. 4A is a diagram showing trend data when the moving speed of impurities is continuously acquired. FIG. 4B is a diagram showing the corrected movement speed in which the movement speed is corrected based on the correction value. FIG. 4 shows the trend data when one measurement is performed in a cycle of 5.5 minutes. In this trend, the movement speed is newly quantified and updated every 5.5 minutes.

Here, the moving speed of impurities (including flocs) may deviate by a certain amount from the moving speed that captures the original charged state of impurities due to the movement of the suspension 300 after being encapsulated in the cell 200. .. This deviation width is not always constant, and varies depending on convection due to the temperature difference between water temperature and air temperature, the degree of dirt adhesion to the cell wall surface, and the elapsed time from chemical cleaning. In addition, the deviation width is expected to fluctuate daily and seasonally. Therefore, in the present embodiment, this deviation width is periodically measured and corrected.

Specifically, it is considered that the movement of impurities due to convection or the like is close to the moving speed when measured at no voltage at the time of measurement. Therefore, during the continuous measurement of the first moving speed, the moving speed (correction value) of impurities in the x-axis direction at no voltage is quantified, and the result of the subsequent measurement is corrected based on this moving speed. ..

Originally, the moving speed (correction value) at no voltage should be almost zero if impurities are stationary after encapsulation, but it will not be zero due to various factors when continuous measurement is performed. Therefore, by periodically quantifying the moving speed (correction value) when there is no voltage and using the correction value to correct the moving speed of impurities contained in the water to be treated to which the voltage is applied, more accurate impurities. It is possible to quantify the speed of electrophoresis according to the charge state of.

The movement speed (correction value) at no voltage may be measured several times a day at regular intervals, or if it fluctuates seasonally, it may be measured seasonally. If the movement speed at no voltage fluctuates even during the day, the measurement may be performed several times during the day and several times during the night, or may be performed several times every hour.

In step S108, the coagulant injection control unit 83 determines the coagulant injection amount to be output to the coagulant injection device 70 based on the corrected moving speed of the impurities.

In step S109, the coagulant injection device 70 injects the coagulant into the mixing pond 20 in accordance with the control from the coagulation control device 80.

In this embodiment, the moving speed (correction value) at no voltage is periodically quantified, and the moving speed of impurities contained in the water to be treated to which the voltage is applied is corrected by using this to make it more accurate. The charged state of impurities can be quantified.

(Second embodiment)
The second embodiment acquires the speed of electrophoresis by reversing the potential of the applied voltage.

The method for measuring the speed of electrophoresis, the speed measuring device for electrophoresis, the aggregation control device, the program, and the aggregation control system according to the second embodiment will be described with reference to FIGS. 5 to 8. The configurations of the electrophoresis speed measuring method, the electrophoresis speed measuring device, the aggregation control device, the program, and the aggregation control system having the same functions as those of the first embodiment are described with the same reference numerals. Omit.

The main configuration difference between the first embodiment and the second embodiment is the cell 500.

FIG. 5 is a diagram showing a cell 500 containing the suspension 300 according to the second embodiment. The difference from the cell 200 according to the first embodiment is that the potential of the applied voltage in the voltage applying unit 530 can be inverted as shown in FIGS. 5 (a) and 5 (b). It is a point. In FIG. 5A, the voltage application unit 530 applies a negative potential to the electrode 510 at the positive end of the x-axis in the figure, and applies a positive potential to the electrode 520 at the negative end. Further, in FIG. 5B, the voltage application unit 530 applies a positive potential to the electrode 520 at the positive end of the x-axis in the figure, and applies a negative potential to the electrode 510 at the negative end.

The cell 500 according to the second embodiment reverses the positive and negative of the potential of the voltage applied to the suspension 300 by changing the potential of the voltage applied in the voltage application unit 530 and inverting the positive electrode and the negative electrode. Is possible.

FIG. 6 is a flowchart showing the operation of the aggregation control device 80 according to the second embodiment.

In step S201, the suspension 300 is passed through the cell 500, and the valves before and after the cell 500 are closed. The suspension 300 is a part of the water to be treated (mixed water) collected from the mixing pond 20. The suspension 300 is collected from the mixing pond 20 and passed through the cell 500. Next, the valves around the cell 500 are closed.

In step S202, a voltage is applied to the suspension 300. The voltage is applied in step S202, for example, as shown in FIG. 5A.

In step S203, the moving speed measuring unit 81 measures the moving speeds of individual impurities (including flocs) in the suspension 300 under voltage application in the x-axis direction and the y-axis direction by image processing. The moving speed measuring unit 81 continuously images impurities in the suspension 300 to which a voltage is applied, and measures the moving speed of the impurities.

In step S204, the suspension 300 in the cell 500 is drained, and the next suspension 300 is sampled.

In step S205, as in step S201, the suspension 300 is passed through the cell 500, and the valves before and after the cell 500 are closed.

In step S206, a voltage obtained by exchanging the applied potential with step S202 is applied to the suspension 300. The voltage is applied in step S206, for example, as shown in FIG. 5 (b).

In step S207, the moving speed measuring unit 81 measures the moving speeds of individual impurities in the suspension 300 under voltage application in the x-axis direction and the y-axis direction by image processing. As shown in FIG. 5B, the moving speed of impurities measured by applying a voltage obtained by exchanging the applied potential with step S202 is referred to as an inversion moving speed.

In step S208, the correction unit 82 calculates a correction value based on the movement speed measured in steps S203 and S207 and the reverse movement speed, and uses the calculated correction value to move the impurity. To correct. At this time, the moving speed to be corrected may be the moving speed measured in step S203 or the moving speed measured in step S207.

As an example, a method of correcting the moving speed in step S208 will be described with reference to FIGS. 7 and 8.

FIG. 7 is a diagram showing trend data when the moving speed according to the second embodiment is continuously measured by alternately changing the applied voltage. In particular, FIG. 7A is a diagram showing trend data when the movement speed is continuously acquired. FIG. 7B is a diagram showing the corrected movement speed after the movement speed is corrected using the correction value.

FIG. 7 shows the trend data when the moving speed is continuously measured as in FIG. 4, but the difference from FIG. 4 is that the direction in which the voltage is applied, that is, the polarity is measured for each measurement. It is a point of replacement. Specifically, the moving speed measuring unit 81 inverts the positive electrode and the negative electrode in the voltage applying unit 530 for each measurement. Therefore, in the electrophoresis of impurities (including flocs), it is observed that the movement in the x-axis direction is reversed for each measurement.

Even in the trend, the moving speed is periodically observed with the positive and negative signs inverted.

Originally, the trend of FIG. 7 (a) should be a mirror target for a moving speed of 0 even if the polarities are exchanged if the movement of impurities at the time of encapsulation is stationary.

However, the trend of FIG. 7A may shift in the positive direction or the negative direction by a certain width due to the influence of convection in the cell 500 during continuous measurement.

Here, in the present embodiment, data is acquired while exchanging the polarities, and while taking the average of the absolute values of the moving speeds in each measurement, the average value of the absolute values is measured in the direction of the original voltage polarity. By adding the code of the movement speed observed at times, the movement speed after correction can be obtained. In the present embodiment, the moving speed (correction value) of the agglomerates that does not depend on the applied voltage is calculated by taking the average of the absolute values of the moving speeds. It is desirable that the average of the absolute values be taken between a plurality of measurements, and for example, the average value of the latest 2 times, 4 times, and 6 times is assumed.

The corrected movement speed is obtained by adding a sign to this average value. The trend of FIG. 7B shows the corrected movement speed in which a sign is added to the average value of the absolute values.

In step S209, the coagulant injection control unit 83 determines the coagulant injection amount to be output to the coagulant injection device 70 based on the corrected movement speed output from the coagulation control device 80.

FIG. 8 is a diagram showing a flocculant injection amount determined based on the corrected movement speed according to the second embodiment. In FIG. 8, the coagulant injection amount is determined from the corrected moving speed shown in FIG. 7 (b).

In step S210, the flocculant injection device 70 injects the flocculant into the mixing pond 20 in accordance with the control from the flocculation control device 80.

In the present embodiment, even when the magnitude of movement in a no-voltage state when the suspension 300 is sealed in the cell 500 constantly fluctuates, it is possible to make a correction that incorporates the suspension 300 continuously. It is possible to obtain an accurate moving speed in the x-axis direction according to the charge state of impurities (including flocs).

As described above, according to the first embodiment to the second embodiment, an electrophoresis speed measuring method capable of continuously, stably and accurately measuring the electrophoresis speed of impurities, an electrophoresis speed measuring device, and the like. Aggregation control devices, programs and aggregation control systems can be provided.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

1 ... Water treatment plant 2 ... Aggregation control system 10 ... Water landing well 11 ... Water quality meter 12 ... Flow meter 20 ... Mixing pond 21 ... Stirrer 22 ... pH meter 30-1, 30-2, 30-3 ... Flock forming pond 31-1, 31-2, 31-3 ... Slow speed stirring device 40 ... Sedimentation pond 41 ... Precipitation pond water quality meter 50 ... Filtration pond 51 ... Filtration pond water level meter 60 ... Target value manual input unit 70 ... Coagulant injection device 80 ... Coagulation control device 81 ... Movement speed measurement unit 82 ... Correction Unit 83 ... Aggregator injection control unit 84 ... Charge state target value calculation unit 90 ... Speed measuring device 200, 500 ... Cell 210, 220, 510, 520 ... Electrode 230 ... Voltage Applying unit 300 ... Suspension 810 ... Light source unit 811 ... Imaging unit 812 ... Speed measuring unit

Claims (14)

A moving speed measuring step for measuring the moving speed of impurities contained in the water to be treated to which a voltage is applied, and a moving speed measuring step.
A correction value acquisition step for acquiring a correction value for correcting the movement speed, and
A correction step of correcting the moving speed using the correction value and outputting it as the electrophoresis speed of impurities contained in the water to be treated.
A method for measuring the speed of electrophoresis of impurities having. A correction value acquisition step for acquiring a correction value for correcting the moving speed of impurities contained in the water to be treated to which a voltage is applied, and a correction value acquisition step.
The movement speed measurement step for measuring the movement speed, and
A correction step of correcting the moving speed using the correction value and outputting it as the electrophoresis speed of impurities contained in the water to be treated.
A method for measuring the speed of electrophoresis of impurities having. The correction value is the moving speed of impurities contained in the water to be treated to which no voltage is applied.
The method for measuring the speed of electrophoresis of impurities according to claim 1 or 2. The correction value is acquired based on the moving speed and the reversing moving speed of impurities contained in the water to be treated which is applied by reversing the potential of the voltage.
The method for measuring the speed of electrophoresis of impurities according to claim 1 or 2. A moving speed measuring unit that measures the moving speed of impurities contained in the water to be treated to which a voltage is applied, and a moving speed measuring unit.
A correction unit that corrects the movement speed using the correction value acquired to correct the movement speed and outputs it as the electrophoresis speed of the impurities.
A speed measuring device for electrophoresis of impurities with. The correction value is the moving speed of impurities contained in the water to be treated to which no voltage is applied.
The speed measuring device for electrophoresis of impurities according to claim 5. The correction value is acquired based on the moving speed and the reversing moving speed of impurities contained in the water to be treated which is applied by reversing the potential of the voltage.
The speed measuring device for electrophoresis of impurities according to claim 5. A moving speed measuring unit that measures the moving speed of impurities contained in the water to be treated to which a voltage is applied, and a moving speed measuring unit.
The coagulant injection control that corrects the movement speed using the correction value acquired to correct the movement speed and determines the coagulant injection amount to be injected by the coagulant injection device based on the corrected movement speed. Department and
Aggregation control device with. The correction value is the moving speed of impurities contained in the water to be treated to which no voltage is applied.
The agglutination control device according to claim 8. The correction value is acquired based on the moving speed and the reversing moving speed of impurities contained in the water to be treated which is applied by reversing the potential of the voltage.
The agglutination control device according to claim 8. On the computer
A moving speed measuring step for measuring the moving speed of impurities contained in the water to be treated to which a voltage is applied, and a moving speed measuring step.
A correction value acquisition step for acquiring a correction value for correcting the movement speed, and
A correction step of correcting the moving speed using the correction value and outputting it as the electrophoresis speed of impurities contained in the water to be treated.
A program to execute. A moving speed measuring unit that measures the moving speed of impurities contained in the water to be treated to which a voltage is applied, and a moving speed measuring unit.
A coagulant injection device that corrects the movement speed using the correction value acquired to correct the movement speed and injects a coagulant in an amount of the coagulant injection amount determined based on the corrected movement speed.
Aggregation control system with. The correction value is the moving speed of impurities contained in the water to be treated to which no voltage is applied.
The agglutination control system according to claim 12. The correction value is acquired based on the moving speed and the reversing moving speed of impurities contained in the water to be treated which is applied by reversing the potential of the voltage.
The agglutination control system according to claim 12.

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