JP3300764B2 - Suspension coagulation test method and coagulant injection amount determination method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for measuring a change in transmitted light intensity continuously measured by one or a plurality of transmitted light intensity measuring devices installed on an extension of one agglutination reaction device.
This agglutination test method determines the quality of the agglutination reaction and determines the optimal amount of coagulant to be injected.It is effective for detecting, detecting, and analyzing the growth process of various particles in the reaction tank. It is effective in the field of coagulation and sedimentation treatment for industrial wastewater.

[0002]

2. Description of the Related Art Conventionally, a coagulation test of a suspension is mainly performed by a jar test method, and an optimum coagulant injection amount has been determined based on the results. However,
The jar test method is performed in a batch method,
It has the disadvantage of requiring time, effort, and experience, and therefore has the disadvantage of not responding to water quality fluctuations over time. There are empirical formula and feedback method as a countermeasure for this.
These are basically methods for determining the coagulant injection amount associated with several water quality items, and have a drawback in that they lack responsiveness and reliability to fluctuations in water quality. In addition, the fuzzy method and PDA
Although there is a law, it is still in the stage of examination and is not practical.

[0003]

The optimum coagulant injection amount in the coagulation and sedimentation process depends on various factors such as water temperature, types and concentrations of various coexisting ions in water, quality and amount of suspension, and stirring conditions. Therefore, it is necessary to determine the optimal coagulant injection amount corresponding to the conditions at each time point. However, as described above, the method for determining the optimal coagulant injection amount based on the conventional coagulation test method (jar test method) requires time, effort, and experience, and has a drawback in terms of responsiveness and reliability to time fluctuation of water quality. is there.

[0004] Therefore, from the change in transmitted light intensity continuously measured by one or a plurality of transmitted light intensity measuring devices installed on the extension of one agglutination reaction device, it is determined whether or not the agglutination reaction is good and the optimum aggregating agent is used. Established a method for continuously estimating the amount of injection, and based on this method, was able to respond quickly to changes in water quality, and in a short time, without the need for labor and experience, to automatically optimize the coagulant injection The aim is to establish a method by which the amount can be determined.

[0005]

Means for Solving the Problems] whether the means of the present invention to solve the problems of creating a mixed solution of coagulant and suspensions of different (a) concentrations continuous manner, or aggregation A first step of injecting a coagulant whose concentration has been continuously changed by an agent concentration changing device into a suspension; and (b) one or a plurality of transmitted light intensity measuring devices including a light source unit and a light receiving unit. In one agglutination reactor equipped,
A second step of continuously pumping a predetermined amount of the mixed liquid having a different coagulant concentration at a predetermined speed, mixing and stirring, and allowing the coagulation reaction to proceed; and (c) a continuous step in the second step. And (d) in the third step, the average transmitted light intensity and its amplitude are obtained from the continuously measured changes in transmitted light intensity, and the aggregation / floc formation speed is calculated from this. (Hereinafter referred to as a flocculation rate), a floc diameter, a floc number and a fourth step of calculating the floc number; and (e) a flocculation rate, a floc diameter, a floc number continuously calculated in the fourth step, and their maximum values or A method for testing the agglutination of a suspension and a method for determining an amount of an aggregating agent to be injected, comprising: a step of judging the quality of the agglutination reaction based on a minimum value and a fifth step of determining an optimal amount of an aggregating agent to be injected.

In an agglutination reaction tank provided with a stirrer and a transmitted light intensity measuring device comprising a light source unit and a light receiving unit,
When the agglutination reaction proceeds with stirring at a predetermined stirring speed, a continuous change in transmitted light intensity (or voltage) occurs as the agglutination proceeds. This transmitted light intensity changes according to the following equation.

[0007]

I = I ₀ exp (−KNπr ² ) (1) I: transmitted light intensity I ₀ ; light source intensity K: constant N: number of particles r: particle radius, ie, transmission as the agglutination reaction proceeds The light intensity will increase. Therefore, the transmitted light intensity reflects the quality of the aggregation and the suitability of the coagulant injection amount, and the optimum coagulant injection amount can be determined based on the transmitted light intensity change. The agglutination test method and the method for determining the amount of coagulant injection of the suspension of the present invention are based on the method of transmitting transmitted light continuously measured by one or more transmitted light intensity measuring devices installed on an extension of one agglutination reaction device. It has the function of automatically determining the optimal coagulant injection amount in a short time and without the need for labor and experience from the change in strength, and measures and calculates the coagulation speed, floc diameter and floc number. Has an action.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited to these drawings and embodiments.

FIG. 1 is a schematic diagram of an apparatus for determining the optimum coagulant injection amount according to the present invention.

FIG. 2A shows a state in which mixed liquids having different concentrations are continuously prepared in the mixed liquid preparation apparatus at a constant time interval. FIG. This shows a state in which a predetermined amount of the mixed liquid having different concentrations is sequentially and continuously supplied at a constant flow rate, and aggregating reaction is progressing according to the aggregating agent concentration in the process of mixing and stirring.

FIG. 3 is a diagram showing a change over time in transmitted light intensity when the embodiment of the present invention is executed by the test apparatus of FIG.

FIG. 4 shows several changes in transmitted light intensity (or voltage) over time obtained when the agglutination reaction is advanced at a fixed coagulant injection amount in an agglutination reaction tank equipped with a transmitted light intensity measuring device. Is overwritten with respect to the injection amount.

FIG. 5 shows the amount of coagulant injection and the change in transmitted light intensity based on the change in transmitted light intensity for each predetermined distance (time) obtained from a plurality of transmitted light intensity measuring devices provided in one agglutination reaction tube. It is redrawn to show the relationship.

FIG. 6 shows a change in transmitted light intensity at a specific coagulant injection amount determined from a continuously measured change in transmitted light intensity, an average agglutination reaction rate distribution per unit time, and a calculation based on this. 5 shows a change in transmitted light intensity.

FIG. 7 shows a mixed solution in which the concentration of the coagulant is continuously changed by the coagulant concentration changing device, which is fed to the coagulation reaction device, and is fed to the coagulation reaction tank having a set of transmitted light intensity measuring devices. 5 shows the temporal changes in transmitted light intensity and flocculant concentration when an embodiment of the present invention is performed.

First, the measuring device shown in FIG. 1 will be described.
The apparatus basically includes (a) a plurality of mixed liquid preparation portions for continuously preparing and sending a mixed liquid of a suspension and a flocculant, and (b) one or more transmitted light intensity measuring devices. Agglutination reaction device part (c) Consisting of three parts: control and analysis part.

In the mixture preparation section, the on-off valve (2) and the first
A predetermined amount of the suspension is introduced into the water tank (A) through the water level meter (3), and a predetermined amount of the coagulant is introduced into the water tank (A) through the on-off valve (4). Rapid stirring by 5). After a certain time, the on-off valve (7) is opened, and water is sent to the agglutination reactor by the metering pump (9).

Water is supplied to the water tank (B) by the same process until the water level in the water tank (A) reaches the second water level gauge (6).
The coagulant is injected and stirred to prepare mixed liquids having different coagulant concentrations, and preparation for the next water supply is completed. When the water level in the water tank (A) reaches the second water level gauge (6), the on-off valves (18 and 7) are opened and closed to start feeding the mixed water in the water tank (B). At this time, the on-off valve (8) is opened to drain the water in the water tank (A), and the inside of the water tank is washed with a test sample, and then water is again introduced into the water tank (A), a coagulant is injected, and stirring is performed. Prepare for water supply.

That is, an admixture in which the concentration of the coagulant is changed stepwise is semi-continuously prepared in each water tank, and after stirring for a predetermined time at a predetermined intensity, a predetermined amount thereof is continuously supplied at a constant speed to the coagulation reaction apparatus. It is a device to send water to.

It is to be noted that the coagulant whose concentration is continuously changed is suspended by the coagulant concentration converter shown in the upper left part of FIG. It is also possible to inject the mixture into a liquid to create a mixture having a continuous concentration change. That is, the concentrated flocculant solution (16) is continuously injected into the dilution water tank (17) filled with a predetermined amount of distilled water by the quantitative pump (14), and is simultaneously quantitatively sent by the pump (9). Suspension (15)
In this manner, a mixture in which the concentration of the flocculant is continuously changed can be prepared by the method of injecting the mixture at the same speed. Here, the rate of change of the flocculant concentration is adjusted by adjusting the rate of water absorption and delivery of the metering pump (14). Further, the flocculant concentration in the diluent and the admixture can be calculated from the flocculant absorption water supply speed and the suspension water supply speed of the metering pumps (14) and (9).

Although not shown, as in the semi-continuous mixed liquid preparation method (upper right in FIG. 1), if a distilled water tank, a water level gauge, a water supply / drainage opening / closing valve, etc. are linked with a process control device, a series of coagulation can be achieved. After the test, the same diluent and admixture preparation process can be repeated, and smooth operation can be performed using a plurality of coagulant concentration converters.

These processes are performed by the control unit (1).
Controlled by 2), in order to make this process proceed smoothly, two or more mixed liquid preparation tanks,
Alternatively, a coagulant concentration converter can be prepared.

On the other hand, the agglutination reaction tube portion is a single transparent tube, and the mixed water is mixed and mixed in the process of flowing at a constant flow rate in the tube.
The agglutination reaction proceeds while being stirred, but in order to adjust the mixing / stirring intensity and to shorten the length of the tube, a bypass flows into the tube,
A partition for causing a swirling flow or the like may be provided. The flow velocity in the pipe is set so as to obtain a predetermined G value. The agglutination reaction tube is set to a predetermined gradient and curvature.

Further, a light source section (10) is provided on the extension of the tube.
One or a plurality of transmitted light intensity measuring devices, each of which includes a light receiving unit (11), are installed at predetermined intervals. Since the flow rate in the agglutination reaction tube is constant, the mixing / stirring time is set by adjusting the distance from the pump to each transmitted light intensity measuring device. Therefore, one transmitted light intensity measuring device detects and measures a transmitted light intensity change for each coagulant injection concentration during a predetermined mixing / stirring time. In addition, it is also possible to arrange a lens between the light source unit and the light receiving unit to enlarge or reduce a change in light intensity according to the particle diameter of the particles.

The arithmetic unit (13) is connected to the light receiving unit (11) by a lead wire, and transmits the light intensity (I) or voltage (I) in each transmitted light intensity measuring device from before the start to the end of a series of agglutination reaction experiments. The time change of V) is measured and recorded, and each aggregation index is calculated based on the data.

FIG. 2A shows a state in which mixed liquids having different concentrations are continuously prepared at a fixed time interval in the mixed liquid preparation apparatus, and FIG. This shows a state in which a predetermined amount of a different mixed liquid is sequentially and continuously supplied at a constant flow rate, and a coagulation reaction according to a coagulant concentration is progressing in the process of mixing and stirring.

A plurality of transmitted light intensity measuring devices (L ₁ , L ₂ ... L _n ) are attached to the agglutination reaction device at fixed intervals, and each point (time; T ₁ , T ₂₎ ..T _n )
The time change of the transmitted light amount (I) or the voltage (V) is measured and recorded.

FIG. 3 is a diagram showing the change over time of the transmitted light intensity measured at each measurement point when the embodiment of the present invention is executed by the measuring apparatus of FIG. Stirring and mixing after the start time; in T _1, is incomplete the progress of the agglutination reaction for a small time, a V-shaped change in the transmitted light intensity changes relatively small in each coagulant injection amount And take the maximum value near the optimal injection volume. Take deeper V-shaped change in the long T ₂ of the agglutination reaction time,
Here, the maximum value is obtained near the optimum injection amount.

FIG. 4 shows a fixed coagulant injection amount (D ₁ , D _{2) in} a coagulation reaction tank equipped with a transmitted light intensity measuring device.
... Dn) are obtained by overwriting changes in transmitted light intensity (or voltage) over time obtained when the agglutination reaction is advanced in D _n ) for several injection amounts. As the coagulant injection amount approaches the optimum value, the coagulation reaction speed increases and the floc diameter (amplitude) also increases, but if the injection is excessive, the speed and the floc diameter decrease. FIG. 3 shown in FIG.
The time corresponds to the change in transmitted light intensity (or voltage) for each coagulant injection amount at T ₁ and T ₂ .

FIG. 5 shows transmitted light at predetermined time intervals (T ₁ , T ₂ ... T _n ) obtained from a plurality of transmitted light intensity measuring devices when the embodiment of the present invention is executed by the measuring device of FIG. Based on the intensity change, the relationship between the coagulant injection amount and the transmitted light intensity change is plotted again. Although a V-shaped transmitted light intensity change according to the agglutination reaction time is obtained, the average transmitted light intensity and amplitude are maximum near the optimum injection amount (De) at any time (T ₁ , T ₂ ... T _n ). Take the value. That is, the best floc formation at each reaction time is performed in the portion corresponding to the valley of the V-shaped change. Therefore, from the transmitted light intensity change obtained by a plurality of transmitted light intensity measuring devices, from the transmitted light intensity change, reading the injection amount at which the transmitted light intensity and the amplitude are maximum values, it is equivalent to the optimal injection amount. Become.

On the other hand, based on the transmitted light intensity variations obtained by the plurality of transmission light intensity measuring device, the coagulant injection amount per time;, combined together the measurement results at _{T 1, T 2 ·· T n} , FIG. As shown in FIG. 4, a time-dependent change in transmitted light intensity (or voltage) for each coagulant injection amount can be obtained. Further, if the aggregation speed distribution and the average transmitted light intensity and amplitude after a predetermined time are obtained for a predetermined coagulant injection amount, the floc diameter and the number at the injection amount can be calculated.

FIG. 6 is a graph showing the time change of the transmitted light intensity at the specific coagulant injection amount obtained by the above method based on the continuous transmitted light intensity change measured by a plurality of transmitted light intensity measuring devices (FIG. 6). FIG. 6A is a diagram showing an average agglutination reaction rate distribution per unit time based on the graph (FIG. 6B), and a time change of transmitted light intensity calculated and plotted based on the graph (FIG. 6C). That is, the time for each coagulant injection amount; T
It is possible to calculate the average transmitted light intensity and amplitude after a predetermined time based on a coagulation velocity distribution at a predetermined coagulant injection amount obtained by joining the measurement results of ₁ , T ₂ ... T _n. Becomes Therefore, Japanese Patent Application No. 1-1124
According to the method of No. 64, the floc diameter at the injection amount,
The numbers can be calculated.

FIG. 7 shows that the mixed solution having the coagulant concentration changed continuously by the coagulant concentration changing device is supplied to the coagulation reaction device, and the water is supplied to the coagulation reaction tank equipped with a set of transmitted light intensity measuring devices. 5 shows the temporal changes in transmitted light intensity and flocculant concentration when an embodiment of the present invention is performed. This result is basically the same as FIG. However, FIG.
Since the concentration of the flocculant continuously changes as shown in FIG. 2B, the time change of the transmitted light intensity takes a smoother V-shaped change, and takes the maximum value near the optimum injection amount.

[0033]

The method of the present invention for testing the agglutination of a suspension and the method for determining the amount of a coagulant to be injected have the above-mentioned effects. (A) Judgment of the agglutination reaction in a shorter time than the conventional method. And (b) have the effect of easily coping with fluctuations in the quality of raw water, and (c) the index of the agglutination reaction used in the present invention is as follows: Automatic measurement, calculation, and output are possible, and thus have the effect of automating the agglutination reaction test and determination of the optimal coagulant injection amount. (D) The test method is based on a number of indices Therefore, there is an effect that the accuracy of determination and determination is improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a test apparatus for carrying out a method for determining an optimum coagulant injection amount according to the present invention.

FIG. 2A is a view showing a state in which mixed liquids having different concentrations are prepared in the mixed liquid preparation apparatus, and FIG. 2B is a diagram in which a predetermined amount of the mixed liquids having different concentrations is successively transferred to one coagulation reaction tube at a constant flow rate. It is a figure which shows a mode that the water is sent temporarily.

FIG. 3 is a diagram showing a change over time in transmitted light intensity when the embodiment of the present invention is executed by the test apparatus of FIG. 1;

FIG. 4 shows the change over time in transmitted light intensity (or voltage) obtained when an agglutination reaction is allowed to proceed with a fixed amount of aggregating agent in an agglutination reaction tank equipped with a transmitted light intensity measuring device. FIG.

FIG. 5 shows the relationship between the amount of coagulant injection and the change in transmitted light intensity based on the change in transmitted light intensity for each predetermined distance (time) obtained from a plurality of transmitted light intensity measurement devices provided in a single agglutination reaction tube. It is a diagram redrawn.

FIG. 6 shows a change in transmitted light intensity at a specific coagulant injection amount obtained from a continuously measured change in transmitted light intensity,
It is a figure which shows the average agglutination-reaction rate distribution per unit time, and the transmitted light intensity change calculated based on this.

FIG. 7 is a flow chart showing an embodiment of the present invention, in which an admixture having a coagulant concentration changed continuously by a coagulant concentration changing device is fed to an agglutination reaction device, and is fed to an agglutination reaction tank equipped with a set of transmitted light intensity measuring devices. It is a figure which shows the time change of the transmitted light intensity and the coagulant density | concentration when an Example is performed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flocculant storage container 2,4,7,8,18 On-off valve 3 First water level gauge 5 Stirrer 6 Second water level meter 9 Metering pump 10 Light source unit 11 Light receiving unit 12 Control device 13 Arithmetic device 14 Metering pump 15 Suspension (raw water) 16 Concentrated flocculant solution 17 Dilution water tank

Claims (4)

(57) [Claims] 1. A (a) to create a liquid mixture of different flocculants and suspensions of concentration continuous manner, or flocculant concentration change instrumentation
The flocculant, whose concentration has been continuously changed by
During the first stage and (b) a light source unit and the light receiving portion and a pair or more of the transmitted light intensity measurement device and agglutination reactor one having a consists of entry,
A second step of continuously pumping a predetermined amount of the mixed liquid having a different coagulant concentration at a predetermined speed, mixing and stirring, and allowing the coagulation reaction to proceed; and (c) a continuous step in the second step. And (d) in the third step, the average transmitted light intensity and its amplitude are obtained from the continuously measured changes in transmitted light intensity, and the aggregation / floc formation speed is calculated from this. (Hereinafter referred to as a flocculation rate), a floc diameter, a floc number and a fourth step of calculating the floc number; and (e) a flocculation rate, a floc diameter, a floc number continuously calculated in the fourth step, and their maximum values or A method for testing the agglutination of a suspension and a method for determining an amount of an aggregating agent to be injected, comprising: judging the quality of the agglutination reaction based on the minimum value and a fifth step of determining an optimal amount of an aggregating agent to be injected. 2. In the third stage, a lens is provided between the light source unit and the light receiving unit, and a group of particles flowing in the agglutination reaction device is enlarged or reduced, so that light corresponding to the particle size of the particles is obtained. The method for testing the agglutination of a suspension and the method for determining the amount of aggregating agent to be injected according to claim 1, wherein the determination of the quality of the agglutination reaction and the optimal amount of the aggregating agent to be injected are determined by expanding or reducing the intensity change. 3. In the third stage, a change in transmitted light intensity continuously measured by one or a plurality of transmitted light intensity measurement devices installed at predetermined intervals on an extension of one agglutination reaction device is obtained. The method of claim 1, wherein the maximum value of the average transmitted light intensity and the amplitude is read, and based on the read value, the quality of the agglutination reaction is determined and the optimal coagulant injection amount is determined. Coagulant injection amount determination method. 4. In a third stage, a time change in transmitted light intensity (or voltage) for each coagulant injection amount is determined based on continuous transmitted light intensity changes obtained from a plurality of transmitted light intensity measuring devices. Further, the aggregation speed distribution at a predetermined coagulant injection amount and the average transmitted light intensity after a predetermined time, the amplitude are obtained, the floc diameter at the injection amount, the floc number is calculated, and based on them, the quality of the coagulation reaction is determined. The method of claim 1, wherein the determination and the optimal coagulant injection amount are determined.