JPH0567322B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention provides a method for controlling the properties of raw water when a flocculant is injected into the raw water in order to flocculate suspended matter from the raw water, remove the precipitate, and discharge it as treated water. Regarding a flocculant injection control method for controlling the amount of flocculant to be injected according to and the subsequent jar test, the amount of flocculant injected is adjusted to the optimum dosage detected by that jar test. ,
From measured or analyzed values of zeta potential, colloidal charge, image analysis information before aggregation (i.e., at least one of the geometric mean diameter, number, and average effective density of aggregates, or pilot filter water head loss rate) This invention relates to a coagulant injection control method in which the optimum injection amount is determined by correcting the optimum injection amount so that the measured value or analysis value of the rapid index approaches the target value. [Prior Art] Conventionally, this type of flocculant injection control method includes:
The optimal injection amount of flocculant detected by performing a jar test when injecting a flocculant (inorganic flocculant or organic flocculant) into raw water to flocculate suspended solids, remove precipitates, and discharge as treated water. It has been proposed that the amount of coagulant to be injected is determined according to the above, and the amount of coagulant to be injected is maintained until the next jar test is performed. [Problems to be solved] However, in the conventional flocculant injection control method, the jar test takes more than 30 minutes, so (i) flocculant injection control is delayed by the time required for the jar test; There are drawbacks and even (ii)
It has the disadvantage that it is not possible to sufficiently suppress fluctuations in the turbidity of treated water due to fluctuations in raw water properties, and as a result,
(iii) In order to maintain the turbidity of the treated water at a desired level regardless of fluctuations in the properties of the raw water, the injection amount of the flocculant must always be set to a large value. Therefore, in order to eliminate these drawbacks, the present invention determines the amount of flocculant to be injected during the intermittently executed jar test to the optimum injection amount detected in the jar test, and also determines the injection amount of the flocculant to be the optimal injection amount detected in the jar test, which is performed intermittently, and the difference between the jar test and the subsequent jar test. Rapid indicators (i.e. flowing current, flowing current difference, agglomerated dispersion state, zeta potential, colloid charge A quick index to the target value consisting of the quantity, image analysis information of the aggregates (i.e. at least one of the geometric mean diameter, number and average effective density of the aggregates) or the measured or analyzed value of the head loss rate of the pilot filter. The present invention aims to provide a flocculant injection control method in which the optimum injection amount is determined by correcting the measured value or analytical value of The first solution to the problem provided by the invention is that ``When injecting a flocculant into raw water in order to flocculate suspended solids from the raw water, remove the precipitate, and discharge it as treated water, it is possible to In the flocculant injection control method, the coagulant injection control method comprises: (a) detecting the optimum injection amount of the coagulant for raw water by a jar test; The second step is to inject the coagulant into the raw water according to the optimum injection amount of the coagulant.
(c) A third step of measuring the flowing current of the raw water into which the flocculant was injected in the second step; (d) A flowing current of the measured value of the flowing current measured in the third step. (e) a fifth step in which a flocculant is injected into the raw water after the second step; (f) a fifth step in which the flocculant is injected into the raw water in the fifth step; (g) a seventh step of comparing the target value of the flowing current held in the third step with the measured value of the flowing current measured in the sixth step; and (h) an eighth step of determining the injection amount of the flocculant in the fifth step according to the results compared in the seventh step. method”. The second solution to the problem provided by the present invention is that ``When a flocculant is injected into raw water in order to flocculate suspended solids from the raw water, remove the precipitate, and discharge it as treated water, the properties of the raw water are changed. In the flocculant injection control method, the flocculant injection amount is controlled according to the flow rate of the raw water. (c) when the optimal injection amount of the flocculant is detected in the first step, flocculation of the raw water is performed according to the optimal injection amount of the flocculant detected in the first step; (d) when the optimum injection amount of the flocculant is detected in the first step, according to the injection amount of the flocculant determined in the third step; a fourth step of injecting a flocculant into the raw water; (e) a fifth step of measuring the flowing current of the raw water into which the flocculant was injected in the fourth step; and (f) measurement in the second step. A sixth step of calculating the measured value of the flowing current difference by subtracting the measured value of the flowing current measured in the fifth step from the measured value of the flowing current obtained in the fifth step.
(g) A seventh step for holding the measured value of the flowing current difference calculated in the sixth step as a target value of the flowing current difference; (h) After the fourth step, the raw water is On the other hand, the eighth step of injecting the flocculant, (i) the ninth step of measuring the flowing current of the raw water into which the flocculant was injected in the eighth step, and (j) the flow current measured in the second step. A tenth step of calculating the measured value of the flowing current difference by subtracting the measured value of the flowing current measured in the ninth step from the measured value of the flowing current.
(k) an eleventh step of comparing the target value of the flowing current difference held in the seventh step and the measured value of the flowing current difference calculated in the tenth step; and a twelfth step of determining the injection amount of the flocculant in the eighth step according to the results compared in the eleventh step.'' A third solution to the problem provided by the present invention is that ``When a flocculant is injected into raw water in order to flocculate suspended solids from raw water, remove precipitates, and discharge as treated water, the properties of the raw water are In a flocculant injection control method that controls the amount of flocculant to be injected according to (c) when the optimum injection amount of the coagulant is detected in the step, the injection amount of the coagulant to the raw water is determined in accordance with the optimum injection amount of the coagulant detected in the first step; (d ) A fourth step of analyzing the flocculation and dispersion state of the raw water into which the flocculant was injected in the third step; (f) a sixth step of injecting a flocculant into the raw water after the third step; (g) a fifth step of injecting a flocculant into the raw water in the sixth step; (h) an eighth step of comparing the target value of the agglomerated and dispersed state held in the fifth step with the analytical value of the agglomerated and dispersed state measured in the seventh step; and (i) a ninth step of determining the injection amount of the flocculant in the sixth step according to the results compared in the eighth step. method”. A fourth solution to the problem provided by the present invention is that ``When a flocculant is injected into raw water in order to flocculate suspended matter from the raw water, remove the precipitate, and discharge it as treated water, the properties of the raw water are changed. In a flocculant injection control method that controls the amount of flocculant to be injected according to (c) when the optimum injection amount of the coagulant is detected in the step, the injection amount of the coagulant to the raw water is determined in accordance with the optimum injection amount of the coagulant detected in the first step; (d ) a fourth step of measuring the zeta potential of the aggregates in the raw water into which the coagulant was injected in the third step; (f) a sixth step of injecting a flocculant into the raw water after the third step; (g) a fifth step of injecting the flocculant into the raw water in the sixth step; a seventh step of measuring the zeta potential of the aggregates in the water; (h) comparing the target value of zeta potential held in the fifth step and the measured value of zeta potential measured in the seventh step; an eighth step; and (i) a ninth step of determining the injection amount of the flocculant in the sixth step according to the results compared in the eighth step. ``Injection control method''. A fifth solution to the problem provided by the present invention is that ``When a flocculant is injected into raw water in order to flocculate suspended solids from the raw water, remove the precipitate, and discharge it as treated water, the properties of the raw water are changed. In a flocculant injection control method that controls the amount of flocculant to be injected according to (c) when the optimum injection amount of the coagulant is detected in the step, the injection amount of the coagulant to the raw water is determined in accordance with the optimum injection amount of the coagulant detected in the first step; (d ) A fourth step of measuring the amount of colloid charge of the raw water into which the flocculant has been injected in the third step; (e) Using the measured value of the amount of colloid charge measured in the fourth step as the target value of the amount of colloid charge (f) a sixth step of injecting a flocculant into the raw water after the third step; (g) a fifth step of injecting a flocculant into the raw water in the sixth step; (h) an eighth step of comparing the target value of the colloid charge amount held in the fifth step with the measured value of the colloid charge amount measured in the seventh step; and (i) a ninth step of determining the injection amount of the flocculant in the sixth step according to the results compared in the eighth step. method”. The second solution to the problem provided by the present invention is that ``When a flocculant is injected into raw water in order to flocculate suspended solids from the raw water, remove the precipitate, and discharge it as treated water, the properties of the raw water are changed. In a flocculant injection control method that controls the amount of flocculant to be injected according to (c) when the optimum injection amount of the coagulant is detected in the step, the injection amount of the coagulant to the raw water is determined in accordance with the optimum injection amount of the coagulant detected in the first step; (d ) a fourth step of measuring at least one of the geometric mean diameter, number, and average effective density of aggregates in the raw water into which the flocculant was injected in the third step; A step for holding at least one measured value of the measured geometric mean diameter, number, and average effective density of the aggregates as a target value of at least one of the geometric mean diameter, number, and average effective density of the aggregates. (f) A sixth step of injecting a flocculant into the raw water after the third step; (g) Geometric mean of the aggregates in the raw water into which the flocculant was injected in the sixth step. a seventh step of measuring at least one of the diameter, number, and average effective density; (h) at least one of the geometric mean diameter, number, and average effective density of the aggregates retained in the fifth step; Eighth step: comparing the target value with at least one of the geometric mean diameter, number, and average effective density of the aggregates measured in the seventh step.
and (i) a ninth step of determining the injection amount of the flocculant in the sixth step according to the results compared in the eighth step. method”. A seventh solution to the problem provided by the present invention is that ``When a flocculant is injected into raw water in order to flocculate suspended solids from the raw water, remove the precipitate, and discharge it as treated water, the properties of the raw water are changed. In a flocculant injection control method that controls the amount of flocculant to be injected according to (c) when the optimum injection amount of the coagulant is detected in the step, the injection amount of the coagulant to the raw water is determined in accordance with the optimum injection amount of the coagulant detected in the first step; (d ) a fourth step of measuring the rate of rise in head loss in the pilot filter of the raw water into which the coagulant was injected in the third step; (e) a measured value of the rate of rise in head loss measured in the fourth step; (f) a sixth step of injecting a flocculant into the raw water after the third step; (g) a flocculant in the sixth step; (h) the target value of the head loss rise rate maintained in the fifth step and the loss measured in the seventh step; (i) a ninth step of determining the amount of coagulant to be injected in the sixth step according to the results of the comparison in the eighth step; A coagulant injection control method characterized by comprising: [Function] The first to seventh flocculant injection control methods according to the present invention are effective when injecting a flocculant into raw water in order to flocculate suspended water from raw water, remove sediment, and discharge it as treated water. The injection amount of the flocculant is controlled according to the properties, and in particular, as specified in the first to seventh solutions in the [Means for solving problems] section, the injection amount of the flocculant is The injection amount of the coagulant is determined to be the optimum injection amount detected by the jar test, and the injection amount of the flocculant between the jar test and the subsequent jar test is determined according to the optimum injection amount detected by the jar test. Rapid indicators when the agent is injected (i.e. flowing current, flowing current difference, agglomerated dispersion state, zeta potential, colloidal charge amount, image analysis information of aggregates (i.e. geometric mean diameter, number and average effective density of aggregates) ) or the measured value or analyzed value of the head loss rate of the pilot filter by correcting the optimum injection amount so that the measured value or the analyzed value of the rapid index approaches the target value. (i) The amount of coagulant to be injected is determined intermittently by a jar test, and a rapid index is used between jar tests to correct the fluctuations in raw water properties, and (ii) the turbidity of the treated water is (iii) It also has the effect of reducing the amount of flocculant injection. [Examples] Next, preferred embodiments of the flocculant injection control method according to the present invention will be described. will be specifically described with reference to the accompanying drawings.However, the examples described below are described to facilitate or promote understanding of the present invention, and do not limit the present invention. In other words, each element disclosed in the embodiments described below includes all design changes and equivalent substitutions that fall within the spirit and technical scope of the present invention. (Explanation of the attached drawings) FIG. 1 is a conceptual diagram showing a coagulation-sedimentation processing apparatus in which flocculant injection control is executed according to the first embodiment of the flocculant injection control method according to the present invention. Flowing current is used as a quick indicator. Figure 2 is an enlarged sectional view showing an example of a flowing ammeter installed in the coagulation-sedimentation treatment equipment shown in Figure 1. 3a to 3d are operation explanatory diagrams for explaining the specific example of the embodiment in FIG. The injection amount and treated water turbidity are plotted. FIG. 4 is a conceptual diagram showing a coagulation and sedimentation processing apparatus in which flocculant injection control is executed according to the second embodiment of the flocculant injection control method according to the present invention, and is a quick indicator. The difference in flowing current is used as FIGS. 5a to 5d are operation explanatory diagrams for explaining the specific example of the embodiment in FIG. Injection volume and treated water turbidity are plotted. FIG. 6 is a conceptual diagram showing a coagulation-sedimentation processing apparatus in which flocculant injection control is executed according to the third embodiment of the flocculant injection control method according to the present invention, and is a quick index. The analysis results of the agglomeration-dispersion state (agglomeration-dispersion ratio, etc.) are used as the method. FIGS. 7a to 7d are operation explanatory diagrams for explaining the specific example of the embodiment in FIG. The injection volume and treated water turbidity are plotted respectively. FIG. 8 is a conceptual diagram showing a coagulation sedimentation processing apparatus in which flocculant injection control is executed according to the fourth embodiment of the flocculant injection control method according to the present invention, and is a quick index The zeta potential of the aggregate is used as FIGS. 9a to 9d are operation explanatory diagrams for explaining a specific example of the embodiment in FIG. The amount and treated water turbidity are plotted. FIG. 10 is a conceptual diagram showing a coagulation-sedimentation processing apparatus in which flocculant injection control is executed according to the fifth embodiment of the flocculant injection control method according to the present invention, and is a rapid index The amount of colloidal charge is adopted as . FIGS. 11a to 11d are operation explanatory diagrams for explaining the specific example of the embodiment in FIG. The injection amount of the agent and the turbidity of the treated water are plotted. FIG. 12 is a conceptual diagram showing a coagulation sedimentation processing apparatus in which flocculant injection control is executed according to the sixth embodiment of the flocculant injection control method according to the present invention, and is a rapid index Image analysis information (such as the geometric mean diameter of aggregates) is used as the 13a to 13d are operation explanatory diagrams for explaining a specific example of the embodiment in FIG. 17, and show target values of raw water turbidity and geometric mean diameter of aggregates, respectively, with respect to elapsed time from the start of operation. , the amount of coagulant injected, and the turbidity of the treated water are plotted, respectively. FIG. 14 is a conceptual diagram showing a coagulation-sedimentation processing apparatus in which flocculant injection control is executed according to the seventh embodiment of the flocculant injection control method according to the present invention, and is a rapid index The target value of head loss in the pilot filter is adopted as 15a to 15d are operational explanatory diagrams for explaining the specific example of the embodiment in FIG. The injection amount and treated water turbidity are plotted. (Configuration of the first embodiment) First, with reference to FIGS. 1 and 2, the first embodiment of the flocculant injection control method according to the present invention will be explained, whereby the flocculant injection control is executed. The configuration will be explained in detail while explaining the configuration of the coagulation and sedimentation processing apparatus. Reference numeral 10 denotes a coagulation-sedimentation treatment apparatus in which injection control of a coagulant is executed by a coagulant injection control method according to the present invention, in which suspended water (hereinafter referred to as "suspended water" such as tap water, sewage, human waste, or factory wastewater) is used as raw water. “Josei”
2) is supplied from a raw water supply source (not shown) through a raw water supply pipe 11A as shown by arrow A, and large foreign substances contained in the raw water (i.e., suspended water) are precipitated. Raw water (i.e., treated water) is supplied from the landing well 12 for removal through the raw water supply pipe 11B, and the coagulant injected by rapid stirring is mixed with the raw water (i.e., suspended water). A rapid stirring pond 13 is used to flocculate the suspended solids to form flocs. a slow stirring pond 14 for slowly stirring the rapid stirring pond effluent to enlarge the aggregates;
A flocculant is applied to the sedimentation basin 15 for allowing suspended water (hereinafter referred to as "slow stirring basin effluent water") given from the water to settle to settle aggregates, and the rapid stirring basin 13 for forming aggregates. A flocculant injection device 16 for injecting (an inorganic flocculant or an organic flocculant) is provided. The rapid stirring basin 13 is provided with a stirring member 13B that is rapidly rotated (that is, rotated at a relatively high speed) by a drive source (for example, an electric motor) 13A. Slow stirring pond 1
4 is provided with a stirring member 14B that is driven to rotate slowly (that is, rotated at a relatively low speed) by a drive source (for example, an electric motor) 14A.
A discharge pipe (not shown) is provided at the bottom of the settling tank 15 to remove the settled aggregates as sludge. The flocculant injection device 16 includes a flocculant storage tank 16A for holding the flocculant.
and a metering pump 16B for metering and supplying the flocculant from the flocculant storage tank 16A to the rapid stirring pond 13. The coagulation and sedimentation treatment device 10 also includes a raw water supply pipe 1
A hydrogen ion concentration index meter (hereinafter also referred to as "raw water PH meter") 17, which is installed for 1B and measures the hydrogen ion concentration index (hereinafter also referred to as "raw water PH") of raw water, and a water sampling pipe. 18a, is arranged in the raw water supply pipe 11B via the water sampling pump 18a ⁺ and the drain pipe 18b, and is arranged to inject the required coagulant amount (i.e., the optimal injection amount) to achieve the optimal flocculation state of the raw water (i.e., suspended water). The apparatus is equipped with a jar test device 18 for intermittently detecting the amount of water. The raw water PH meter 17 is provided only for evaluating the flocculant injection control method according to the present invention, and may be removed if desired. The coagulation sedimentation treatment device 10 further includes a raw water supply pipe 1
1B and the rapid stirring tank 13 for measuring the flowing current of the raw water (i.e. , suspended water) into which the flocculant has been injected, and the processing as shown by arrow B from the settling tank 15. A treated water turbidity meter 20 is installed for the treated water discharge pipe 11C for discharging water and measures the turbidity of the treated water (hereinafter also referred to as "treated water turbidity"). There is. Incidentally, the flow ammeter 19 temporarily holds a sample (specifically, "raw water injected with flocculant") collected from the rapid stirring pond 13B via the water sampling pipe 19a and the water sampling pump 19 ⁺ . A cylindrical container 19A that is used for measurement of flowing current and then discharged to a rapid stirring pond 13B via a drainage pipe 19b, and two electrodes 19B that are spaced apart from each other on the inner peripheral surface of the cylindrical container 19A. , 19C, and a piston 1 disposed inside the cylindrical container 19A and reciprocated by a power source 19D located outside the cylindrical container 19A to forcibly move the sample.
9E and connecting wire 19 to electrodes 19B and 19C.
c, 19d, and the piston 19
An ammeter 19F measures the current generated between the electrodes 19B and 19C during the movement of the sample due to the reciprocating motion of E, amplifies it appropriately, and outputs it as a measured value of flowing current to the subsequent holding device 21 and comparison circuit 23. It encompasses. Treated water turbidity meter 20
is provided only for evaluating the flocculant injection control method according to the present invention, and may be removed if desired. In addition, the flocculating sedimentation treatment device 10 is connected to a jar test device 18 and a flow ammeter 19 , and the flocculant is injected according to the optimum injection amount of the flocculant detected by the jar test device 18. The measured value of the flowing current by the flowing ammeter 19 is sent to the output signal of the jar test device 18 (that is, the detection result of the optimum injection amount of the flocculant is sent to the control device 24, which will be described later).
(It is a signal to notify that the coagulant has been output, and may also be the detection result of the optimal injection amount of coagulant)
A holding device 21 is connected to the flowing ammeter 19 and the holding device 21 to hold the flowing current and output it as a “target value of flowing current” according to ” and “measured value of flowing current” given from flowing ammeter 19 .
a comparison circuit 23 for comparing the
3, and determines the amount of coagulant to be injected according to the comparison result of the comparison circuit 23 (i.e., the difference between the "target value of flowing current" and the "measured value of flowing current"). A control device 24 is provided for supplying an injection control signal to the flocculant injection device 16 as an injection control signal. (Operation of the first embodiment) Furthermore, with reference to FIGS. 1 and 2, the first embodiment of the flocculant injection control method according to the present invention will be described, whereby the flocculant injection control is executed. The operation will be explained in detail while explaining the operation of the coagulation and sedimentation treatment apparatus. Coagulation and Sedimentation Operation Suspended water supplied from a raw water supply source (not shown) as raw water through the raw water supply pipe 11A as shown by arrow A is treated as raw water after large foreign substances are precipitated and removed in the landing well 12. It is supplied to the rapid stirring pond 13 via the supply pipe 11B. The suspended water (that is, raw water) supplied to the rapid stirring pond 13 is rapidly stirred with a flocculant injected from the flocculant injection device 16 in order to flocculate the suspended solids and form aggregates (that is, flocs). It is then mixed. The raw water in which aggregates have been formed in the rapid stirring pond 13 is transferred to the slow stirring pond 14 as rapid stirring pond outflow water.
is supplied to The rapid stirring pond effluent supplied to the slow stirring pond 14 is slowly stirred to enlarge the aggregates, and then is supplied to the settling basin 15 as slow stirring pond effluent. The slow stirring pond outflow water supplied to the settling basin 15 is
It is left undisturbed to allow the aggregates to settle. The settled aggregates are removed as sludge through a discharge pipe (not shown) formed at the bottom of the settling tank 15. On the other hand, the water flowing out of the slow stirring pond from which the flocs have been precipitated is discharged as treated water from the settling basin 15 through the treated water discharge pipe 11C as shown by arrow B, and then sent to a subsequent treatment device (not shown). is supplied to Coagulant injection control Suspension water (i.e., raw water) supplied from the landing well 12 to the rapid stirring pond 13 is controlled at the optimum injection amount of coagulant (i.e., when the coagulant is injected to achieve the desired coagulation state). In order to detect the amount of flocculant injected corresponding to , a portion of the flocculant is collected as a sample in the jar test device 18. The jar test device 18 collects water from the raw water supply pipe 13 intermittently (for example, every hour).
Measure the optimal injection amount of flocculant. The flocculant detected by the jar test device 18 is provided to the control device 24 each time it is detected. Every time the control device 24 is given the detection result of the optimum injection amount of flocculant from the jar test device 18, the holding device 21 is given a signal from the jar test device 18 to notify the holding device 21 of this fact. The holding device 21 is operated for an appropriate amount of time from the time when the optimum injection amount of flocculant is given from the jar test device 18 (i.e., the time required for the flocculant injected in the rapid stirring pond 13 to be sufficiently stirred).
, the measured value of the flowing current given from the flowing ammeter 19 as described below is held as the measured value of the flowing current corresponding to the optimum injection amount of the flocculant (referred to as "optimal flowing current"), The comparator circuit 2 uses the held measured value as the “target value of flowing current” until a new measured value of the optimum flowing current is held.
Continue outputting towards 3. The comparison circuit 23 calculates the difference between the "target value of the flowing current" given by the holding device 21 and the "measured value of the flowing current" given as described later from the flowing ammeter 19 , and calculates the difference as a comparison result. The signal is output to the control device 24. The control device 24 determines the injection amount of the flocculant to be the optimum injection amount when the optimum injection amount of the flocculant is given from the jar test device 18, and when the optimum injection amount of the flocculant is not given from the jar test device 18. The injection amount of the flocculant is determined (i.e., the optimum injection amount detected by the immediately previous jar test is corrected) so that the comparison result given from the comparator circuit 23 becomes 0 (i.e., between the jar tests), and It is output to the flocculant injection device 16 as an injection control signal. In the flocculant injection device 16, a metering pump 16B is operated in response to a flocculant injection control signal given from the control device 24, and an appropriate amount of flocculant is injected from the flocculant storage tank 16A toward the rapid stirring pond 13. do. The rapid stirring pond 13 is connected to the holding device 2 by measuring the flowing current of the raw water into which the flocculant is injected by the flowing ammeter 19 .
1 and the comparison circuit 22. As is clear from the above, according to the present invention,
The injection amount of the flocculant at the time when the optimum injection amount of the flocculant is detected by the jar test device 18 is determined to be the optimum injection amount, and Since the injection amount can be corrected according to changes in raw water properties, the injection amount of flocculant can be changed immediately in response to changes in raw water properties, and the turbidity of treated water can be reduced while avoiding unnecessary increases in the injection amount of coagulant. Fluctuations can be suppressed reliably. Specific Example 1 In addition, with reference to FIG. 1 and FIGS. 3 a to 3 d, specific numerical values will be given in order to further deepen the understanding of the first embodiment of the flocculant injection control method according to the present invention. This will be explained in detail. Here, river water is used as raw water, and a first coagulation-sedimentation treatment device in which injection control of a coagulant is executed by a coagulant injection control method according to the present invention;
The coagulant was supplied to a second flocculant-sedimentation processing apparatus in which flocculant injection control was executed by the flocculant injection control method disclosed as a prior art. The first and second coagulation and sedimentation treatment devices are both equipped with a rapid stirring basin, a slow stirring basin, and a settling basin of the same structure, and the residence time of the rapid stirring basin, slow stirring basin, and settling basin is 3. minutes, 27 minutes and 2 hours
The treatment time was 30 minutes, the raw water (ie suspended water) throughput was 100 m ³ /h, and polyaluminum chloride (so-called "PAC") was used as the flocculant. Raw water PH changes over time from the start of operation.
It changed between 7.5 and 6.5 as shown in Figure 3a. Incidentally, the raw water turbidity and raw water temperature were almost constant at 20°C and 25°C, respectively. Furthermore, the target turbidity of the treated water was 2 degrees. Example 1 The optimal amount of coagulant to be injected into the raw water was detected using a jar test device at the start of operation and every hour after the start of operation, as plotted in Figure 3c. Ta. The target value of the flowing current was the flowing current when the optimum amount of flocculant was injected into the rapid stirring pond, and was as shown in FIG. 3b. The injection amount of flocculant was determined as shown by the solid line in Figure 3c. The turbidity of the treated water was as shown by the solid line in Figure 3d, and had substantially reached 2 degrees. Comparative Example 1 The dosage of flocculant was determined according to the optimum dosage detected by the jar test device and maintained until the next jar test, as shown by the dashed line in Figure 3c. The turbidity of the treated water, as shown by the broken line in Figure 3d, fluctuated greatly when the pH of the raw water decreased. Comparison of Example 1 and Comparative Example 1 As is clear from the above, in Example 1, the injection amount of flocculant was adjusted to the optimum injection amount of flocculant detected by the jar test, which was performed intermittently. A rapid indicator (here, flowing current) when the flocculant is injected according to the optimal injection amount detected by the jar test, and the injection amount of the flocculant between the jar test and the subsequent jar test is determined. Since the measured value of the rapid index was corrected so that it approached the target value consisting of (i) compared to Comparative Example 1, it was possible to change the injection amount of coagulant in response to changes in the raw water properties more quickly, which in turn (ii) compared to Comparative Example 1. Compared to Example 1, there was not much difference in the amount of coagulant injected, and as a result, (iii)
Compared to Comparative Example 1, fluctuations in the turbidity of the treated water could be reliably suppressed. (Structure and operation of the second embodiment) Also, with reference to FIG. 4, the second embodiment of the flocculant injection control method according to the present invention will be described, in which the flocculant injection control is executed. While explaining the coagulation and sedimentation treatment apparatus, its structure and operation will be explained in detail. In the second embodiment, as is clear from a comparison between FIG . 1 and FIG. The raw water flowing current (i.e., the flowing current of "raw water to which the flocculant has not yet been injected") and the flocculating flowing current (i.e., the flowing current of "raw water to which the flocculant has already been injected") measured in step 19 are calculated by a computing device. 22, the flow current difference (that is, the result of subtracting the cohesive flow current from the raw water flow current) is calculated and applied to the holding device 21 and the comparison circuit 23. They have essentially the same structure and function. That is, the flowing ammeter 19 sends "raw water to which no flocculant has yet been injected" and "raw water to which the flocculant has already been injected" to the water sampling pump 19a ⁺ and the water sampling pipes 19a, 19a ^* , 19a ^**. Therefore, after alternately sampling the raw water from the raw water supply pipe 11B and the rapid stirring pond 13 and measuring the raw water flowing current and the flocculating flowing current alternately, the raw water is discharged to the rapid stirring pond 13 via the drainage pipe 19b. The arithmetic device 22 is a flowing ammeter 1
Temporarily hold the measured raw water flowing current and the aggregated flowing current given from 9, and subtract the measured value of the aggregated flowing current from the measured value of the raw water flowing current to obtain the "measured value of the flowing current difference". is determined and output to the holding device 21 and comparison circuit 23. In other words, in the second embodiment, the flowing current difference functions as a quick indicator equivalent to the flowing current in the first embodiment. Therefore, in order to simplify the explanation, the same reference numerals as in the first embodiment are given to the same members as in the first embodiment, so that the same reference numerals as in the first embodiment are used to refer to the same members. Detailed explanation will be omitted. Specific Example 2 In addition, with reference to FIGS. 4 and 5 a to 5 d, specific numerical values will be given in order to further deepen the understanding of the second embodiment of the flocculant injection control method according to the present invention. This will be explained in detail. Here, the first and second coagulation and sedimentation treatment devices used in Example 1 were used, river water was used as the raw water, and polyaluminum chloride (so-called "PAC") was used as the coagulant. Raw water PH changes over time from the start of operation.
It changed between 7.5 and 6.5 as shown in Figure 5a. Incidentally, the raw water turbidity and raw water temperature were almost constant at 20°C and 25°C, respectively. Furthermore, the target turbidity of the treated water was 2 degrees. Example 2 The optimum amount of coagulant to be injected into the raw water was detected using a jar test device at the start of operation and every hour after the start of operation, and was found to be as plotted in Figure 5c. Ta. The target value of the flow current difference is the result of subtracting the measured value of the flocculant flow current when the flocculant is injected into the rapid stirring pond at the optimum injection amount from the measured value of the raw water flow current, so it is shown in Figure 5b. It was as shown. The injection amount of flocculant was determined as shown by the solid line in Figure 5c. The turbidity of the treated water was as shown by the solid line in Figure 5d, and had substantially reached 2 degrees. Comparative Example 2 The dosage of flocculant was determined according to the optimum dosage detected by the jar test device and maintained until the next jar test, as shown by the dashed line in Figure 5c. The turbidity of the treated water, as shown by the broken line in Figure 5d, fluctuated greatly when the pH of the raw water decreased. Comparison of Example 2 and Comparative Example 2 As is clear from the above, in Example 2, the injection amount of the flocculant was adjusted to the optimal injection amount of the flocculant detected by the jar test, which was performed intermittently. A quick indicator (here, the difference in flowing current ) Since the measured value of the rapid index was corrected so as to approach the target value consisting of Compared to Comparative Example 2, there was not much excess or deficiency in the amount of coagulant injected, and as a result,
(iii) Compared to Comparative Example 2, fluctuations in turbidity of treated water could be reliably suppressed. (Structure and operation of the third embodiment) Furthermore, with reference to FIG. 6, the third embodiment of the flocculant injection control method according to the present invention will be described, in which the flocculant injection control is executed. While explaining the coagulation and sedimentation treatment apparatus, its structure and operation will be explained in detail. As is clear from a comparison between FIG . 1 and FIG .
This embodiment has substantially the same structure and operation as the embodiment. That is, the coagulation dispersion analyzer 29 collects the raw water into which the coagulant has been injected from the rapid stirring pond 13 using the water sampling pump 19a ⁺ and the water sampling pipe 19a and analyzes the coagulation and dispersion state.
It is discharged to the rapid stirring pond 13 through the . The analysis results of the agglomerated and dispersed state are stored in the holding device 21 and the comparison circuit 2.
It is output towards 3. In other words, in the third embodiment, the analysis result of the agglomeration and dispersion state obtained by the aggregation dispersion analyzer 29 (agglomeration dispersion ratio, geometric mean diameter of aggregates, etc.) is equivalent to the flowing current in the first embodiment. It functions as a quick indicator. Therefore, in order to simplify the explanation, the same reference numerals as in the first embodiment are given to the same members as in the first embodiment, so that the same reference numerals as in the first embodiment are used to refer to the same members. Detailed explanation will be omitted. Specific Example 3 In addition, with reference to FIGS. 6 and 7 a to 7 d, specific numerical values will be given in order to further deepen the understanding of the third embodiment of the flocculant injection control method according to the present invention. This will be explained in detail. Here, the first and second coagulation and sedimentation treatment devices used in Example 1 were used, river water was used as the raw water, and polyaluminum chloride (so-called "PAC") was used as the coagulant.
In addition, as the coagulation dispersion analyzer 29 , a coagulation dispersion analyzer PDA2000 manufactured by Rank Brothers is used.
We focused on the agglomeration-dispersion ratio among the aggregation states. The raw water temperature varied between 25°C and 15°C as time elapsed from the start of operation, as shown in Figure 7a. Incidentally, the raw water turbidity and raw water PH were almost constant at 20 degrees and 7.5, respectively. Also,
The target turbidity of the treated water was 2 degrees. Example 3 The optimal amount of coagulant to be injected into the raw water was detected using a jar test device at the start of operation and every hour after the start of operation, and was found to be as plotted in Figure 7c. Ta. The target value of the flocculation-dispersion ratio was the flocculation-dispersion ratio when the optimum amount of flocculant was injected into the rapid stirring pond, and was as shown in FIG. 7b. The injection amount of flocculant was determined as shown by the solid line in Figure 7c. The turbidity of the treated water was as shown by the solid line in Figure 7d, and had substantially reached 2 degrees. Comparative Example 3 The dosage of flocculant was determined according to the optimum dosage detected by the jar test device and maintained until the next jar test, as shown by the dashed line in Figure 7c. The turbidity of the treated water, as shown by the broken line in Figure 7d, varied greatly when the raw water temperature decreased. Comparison of Example 3 and Comparative Example 3 As is clear from the above, in Example 3, the injection amount of flocculant was adjusted to the optimum injection amount of flocculant detected by the jar test, which was performed intermittently. A quick indicator (here, the flocculation-dispersion ratio ) Since the measured value of the rapid index was corrected so as to approach the target value consisting of Compared to Comparative Example 3, there was not much difference in the amount of coagulant injected, and as a result,
(iii) Compared to Comparative Example 3, fluctuations in turbidity of treated water could be reliably suppressed. (Structure and operation of the fourth embodiment) Furthermore, with reference to FIG. 8, regarding the fourth embodiment of the flocculant injection control method according to the present invention,
The structure and operation of the coagulation-sedimentation processing apparatus will be explained in detail while explaining the coagulation-sedimentation processing apparatus by which injection control of the coagulant is executed. As is clear from a comparison between FIG . 1 and FIG . They have essentially the same structure and function. That is, the zeta electrometer 39 is connected to the water sampling pump 1
9a ⁺ and water sampling pipe 19a to collect the raw water into which the flocculant has been injected from the rapid stirring pond 13 and measure the zeta potential of the aggregates.
It is discharged to the rapid stirring pond 13 via 9b. The measured value of the zeta potential is obtained by the holding device 21 and the comparison circuit 2.
It is output towards 3. In other words, in the fourth embodiment, the zeta potential measured by the zeta electrometer 39 functions as a quick indicator equivalent to the flowing current in the first embodiment. Therefore, in order to simplify the explanation, the same reference numerals as in the first embodiment are given to the same members as in the first embodiment, so that the same reference numerals as in the first embodiment are used to refer to the same members. Detailed explanation will be omitted. Specific Example 4 In addition, with reference to FIGS. 8 and 9 a to 9 d, specific numerical values will be given in order to further deepen the understanding of the fourth embodiment of the flocculant injection control method according to the present invention. This will be explained in detail. Here, the first and second coagulation and sedimentation treatment devices used in Example 1 were used, river water was used as the raw water, and polyaluminum chloride (so-called "PAC") was used as the coagulant.
In addition, the zeta potential meter 39 is a zeta potential automatic measuring device ZR- manufactured by Comline Sanderson.
12 was used. Raw water PH changes over time from the start of operation.
It changed between 7.5 and 6.5 as shown in Figure 9a. Incidentally, the raw water turbidity and raw water temperature were almost constant at 20°C and 25°C, respectively. Furthermore, the target turbidity of the treated water was 2 degrees. Example 4 The optimal amount of coagulant to be injected into the raw water was detected using a jar test device at the start of operation and every hour after the start of operation, as plotted in Figure 9c. Ta. The target value of the zeta potential was the zeta potential when the optimum amount of coagulant was injected into the rapid stirring pond, and was as shown in FIG. 9b. The injection amount of flocculant was determined as shown by the solid line in Figure 9c. The turbidity of the treated water was as shown by the solid line in Figure 9d, and had substantially reached 2 degrees. Comparative Example 4 The dosage of flocculant was determined according to the optimum dosage detected by the jar test device and maintained until the next jar test, as shown by the dashed line in Figure 9c. The turbidity of the treated water, as shown by the broken line in Figure 9d, fluctuated greatly when the pH of the raw water decreased. Comparison of Example 4 and Comparative Example 4 As is clear from the above, in Example 4, the injection amount of the flocculant was adjusted to the optimum injection amount of the flocculant detected by the jar test, which was performed intermittently. A rapid index (herein, zeta potential) when the flocculant is injected according to the optimal injection amount detected by the jar test and the flocculant injection amount between the jar test and the subsequent jar test. Since the measured value of the rapid index was corrected so that it approached the target value consisting of (i) compared to Comparative Example 4, it was possible to change the injection amount of coagulant in response to changes in the raw water properties more quickly, and in turn (ii) compared to Comparative Example 4. Compared to Example 4, there was not much excess or deficiency in the amount of coagulant injected, and as a result,
(iii) Compared to Comparative Example 4, fluctuations in turbidity of treated water could be reliably suppressed. (Structure and operation of fifth embodiment) In addition, with reference to FIG. 10, regarding the fifth embodiment of the flocculant injection control method according to the present invention,
The structure and operation of the coagulation-sedimentation processing apparatus will be explained in detail while explaining the coagulation-sedimentation processing apparatus by which injection control of the coagulant is executed. As is clear from a comparison between FIG. 1 and FIG. 10, the fifth embodiment is different from the first embodiment except that a colloid charge amount measuring device 49 is provided in place of the flowing ammeter 19. It has substantially the same structure and function as . That is, the colloid charge quantity measuring device 49 measures the colloid charge quantity by collecting the raw water into which the flocculant has been injected from the rapid stirring pond 13 using the water sampling pump 19a ⁺ and the water sampling pipe 19a, and then measuring the colloid charge quantity. It is discharged to the rapid stirring pond 13 through the . The measured value of the amount of colloid charge is output to the holding device 21 and the comparison device 23. In other words, in the fifth embodiment, the amount of colloid charge measured by the colloid charge amount measuring device 49 functions as a quick indicator equivalent to the flowing current in the first embodiment. Therefore, here, in order to simplify the explanation, the same reference numbers as in the first embodiment are given to the same members as those in the first embodiment. Detailed explanation will be omitted. Specific Example 5 In addition, with reference to FIG. 10 and FIGS. 11 a to 11 d, specific numerical values will be given in order to further deepen the understanding of the fifth embodiment of the flocculant injection control method according to the present invention. This will be explained in detail. Here, the first and second coagulation and sedimentation treatment devices used in Example 1 were used, river water was used as the raw water, and polyaluminum chloride (so-called "PAC") was used as the coagulant.
In addition, as the colloid charge amount measuring device 49 , an automatic titration device using dual wavelength photometry was used (patent application
62-273550 and Japanese Patent Application No. 62-273550). The turbidity of the raw water varied between 300 degrees and 100 degrees as shown in Figure 11a with the passage of time from the start of operation. By the way, raw water temperature and raw water PH are
They were almost constant at 20 degrees and 7.5 degrees, respectively.
Furthermore, the turbidity of the treated water was targeted at 2 degrees. Example 5 The optimal amount of coagulant to be injected into the raw water was detected using a jar test device at the start of operation and every hour after the start of operation, and was found to be as plotted in Figure 11c. Ta. The target value of the colloid charge amount was the colloid charge amount when the optimum amount of flocculant was injected into the rapid stirring pond, and was as shown in FIG. 11b. The injection amount of flocculant was determined as shown by the solid line in Figure 11c. The turbidity of the treated water was as shown by the solid line in Figure 11d, and had substantially reached 2 degrees. Comparative Example 5 The injection amount of flocculant was determined according to the optimum injection amount detected by the jar test device and was maintained until the next jar test, so that Figure 11c
It was as shown by the broken line. The turbidity of the treated water, as shown by the broken line in Figure 11d, fluctuated greatly when the turbidity of the raw water increased. Comparison of Example 5 and Comparative Example 5 As is clear from the above, in Example 5, the injection amount of the flocculant was adjusted to the optimum injection amount of the flocculant detected by the jar test, which was performed intermittently. A quick indicator (here, colloidal charge ), so the measured value of the rapid index was corrected to approach the target value consisting of (i)
Compared to Comparative Example 5, the amount of coagulant injected can be changed immediately in response to changes in the raw water properties, and (ii) Compared to Comparative Example 5, there is not much excess or deficiency in the amount of coagulant injected, resulting in (iii) ) Compared to Comparative Example 5, fluctuations in the turbidity of the treated water could be reliably suppressed. (Structure and operation of the sixth embodiment) In addition, with reference to FIG. The structure and operation of the coagulation and sedimentation processing apparatus will be explained in detail. As is clear from a comparison between FIG . 1 and FIG .
This embodiment has substantially the same structure and operation as the embodiment. That is, the image analysis device 59
9a ⁺ and the water sampling pipe 19a, the raw water injected with the flocculant is sampled from the slow stirring pond 14, subjected to image analysis, and then discharged to the rapid stirring pond 13 via the drainage pipe 19b. The results of the image analysis (ie, image analysis information) are output to the holding device 21 and the comparison device 23. In other words, in the sixth embodiment, the image analysis information (at least one of the geometric mean diameter, number, and average effective density of aggregates) analyzed by the image analysis device 59 is the same as that in the first embodiment. It functions as a quick indicator equivalent to the flowing current in . Therefore, in order to simplify the explanation, the same reference numerals as in the first embodiment are given to the same members as in the first embodiment, so that the same reference numerals as in the first embodiment are used to refer to the same members. Detailed explanation will be omitted. Specific Example 6 In addition, with reference to FIG. 12 and FIGS. 13 a to 13 d, specific numerical values will be given in order to further deepen the understanding of the sixth embodiment of the flocculant injection control method according to the present invention. This will be explained in detail. Here, the first and second coagulation and sedimentation treatment devices used in Example 1 were used, river water was used as the raw water, and polyaluminum chloride (so-called "PAC") was used as the coagulant. Furthermore, as the image analysis device 59 , one was used that detects the aggregation state of the aggregates (here, the geometric mean diameter of the aggregates) by utilizing fluctuations in transmitted light. The raw water turbidity changed between 300 degrees and 100 degrees as shown in Figure 13a with the passage of time from the start of operation. By the way, raw water temperature and raw water PH are
They were almost constant at 20 degrees and 7.5 degrees, respectively.
Furthermore, the turbidity of the treated water was targeted at 2 degrees. Example 6 The optimal amount of coagulant to be injected into the raw water was detected using a jar test device at the start of operation and every hour after the start of operation, as plotted in Figure 13c. Ta. The target value of the geometric mean diameter of the aggregates was the geometric mean diameter of the aggregates when the optimum amount of flocculant was injected into the rapid stirring pond, and was as shown in FIG. 13b. The injection amount of flocculant was determined as shown by the solid line in Figure 13c. The turbidity of the treated water was as shown by the solid line in Figure 13d, and had substantially reached 2 degrees. Comparative Example 6 The injection amount of flocculant was determined according to the optimum injection amount detected by the jar test device and was maintained until the next jar test, so that Figure 13c
It was as shown by the broken line. The turbidity of the treated water, as shown by the broken line in Figure 13d, fluctuated greatly when the turbidity of the raw water increased. Comparison of Example 6 and Comparative Example 6 As is clear from the above, in Example 6, the injection amount of the flocculant was adjusted to the optimal injection amount of the flocculant detected by the jar test, which was performed intermittently. A quick indicator (here, the amount of flocculant injected between a jar test and a subsequent jar test according to the optimum dosage detected by the jar test) Since the measured value of the rapid index was corrected so as to approach the target value consisting of (geometric mean diameter), (i) compared to Comparative Example 6, the injection amount of flocculant could be changed quickly in response to changes in raw water properties; (ii) Comparative example 6
Compared to Comparative Example 6, there was no apparent excess or deficiency in the amount of coagulant injected, and as a result, fluctuations in the turbidity of the treated water could be reliably suppressed compared to (iii) Comparative Example 6. (Structure and operation of seventh embodiment) Finally, with reference to FIG. 14, regarding the seventh embodiment of the flocculant injection control method according to the present invention,
The structure and operation of the coagulation-sedimentation processing apparatus will be explained in detail while explaining the coagulation-sedimentation processing apparatus by which injection control of the coagulant is executed. As is clear from a comparison between FIG. 1 and FIG. 14, the seventh embodiment is substantially the same as the first embodiment, except that a pilot filter 69 is provided in place of the flowing ammeter 19 . They have the same structure and function. That is, the pilot filter 69 collects the raw water into which the flocculant has been injected from the rapid stirring pond 13 using the water sampling pump 19a ⁺ and the water sampling pipe 19a and measures the rate of increase in head loss, and then drains the drain pipe 19b. It is discharged to the rapid stirring pond 13 through the pump.
The measured value of the rising speed of the head loss is outputted to the holding device 21 and the comparison circuit 23. In other words, in the seventh embodiment, the head loss rising speed measured by the pilot filter 69 functions as a quick index equivalent to the flowing current in the first embodiment. Therefore, in order to simplify the explanation, the same reference numerals as in the first embodiment are given to the same members as in the first embodiment, so that the same reference numerals as in the first embodiment are used to refer to the same members. Detailed explanation will be omitted. Specific Example 7 In addition, with reference to FIGS. 14 and 15 a to d, specific numerical values will be given in order to further deepen the understanding of the seventh embodiment of the flocculant injection control method according to the present invention. This will be explained in detail. Here, the first and second coagulation and sedimentation treatment devices used in Example 1 were used, river water was used as the raw water, and polyaluminum chloride (so-called "PAC") was used as the coagulant. The raw water temperature varied between 25°C and 15°C as time elapsed from the start of operation, as shown in Figure 15a. Incidentally, the raw water turbidity and raw water PH were almost constant at 20 degrees and 7.5, respectively. Furthermore, the turbidity of the treated water was targeted at 2 degrees. Example 7 The optimal amount of coagulant to be injected into the raw water was detected using a jar test device at the start of operation and every hour after the start of operation, as plotted in Figure 15c. Ta. The target value of the head loss rise rate in the pilot filter is the head loss rise rate when the optimum injection amount of flocculant is injected into the rapid stirring pond.
It was as shown in Figure 15b. The injection amount of flocculant was determined as shown by the solid line in Figure 15c. The turbidity of the treated water was as shown by the solid line in Figure 15d, and had substantially reached 2 degrees. Comparative Example 7 The injection amount of flocculant was determined according to the optimum injection amount detected by the jar test device and was maintained until the next jar test, so that Figure 15 c
It was as shown by the broken line. The turbidity of the treated water, as shown by the broken line in Figure 15d, fluctuated greatly when the pH of the raw water decreased. Comparison of Example 7 and Comparative Example 7 As is clear from the above, in Example 7, the injection amount of the flocculant was adjusted to the optimal injection amount of the flocculant detected by the jar test, which was performed intermittently. A quick indicator (here, the amount of flocculant injected in the pilot filter) is determined, and the injection amount of flocculant between the jar test and the subsequent jar test is determined according to the optimum injection amount detected by the jar test. Since the measured value of the rapid index was corrected so as to approach the target value consisting of (head loss rate of rise), (i) compared to Comparative Example 7, it was possible to change the amount of coagulant injection in response to changes in raw water properties more quickly; In addition, compared to (ii) Comparative Example 7, there is not much difference in the amount of coagulant injected, and as a result, (iii) Comparative Example 7.
Fluctuations in treated water turbidity were reliably suppressed compared to the previous method. (3) Effects of the invention As is clear from the above, the first effect of the present invention is
The seventh coagulant injection control method is to control the injection amount of the coagulant depending on the properties of the raw water when the coagulant is injected into the raw water in order to coagulate the suspended water from the raw water, remove the precipitate, and discharge it as treated water. In particular, as specified in the first to seventh solutions in the [Means for solving problems] section, the amount of coagulant injected during the intermittent jar test is controlled by the amount detected by the jar test. A quick indicator ( That is, flowing current, flowing current difference, agglomerated dispersion state, zeta potential, colloid charge amount, image analysis information of aggregates (at least one of geometric mean diameter, number, and average effective density of aggregates) or pilot (i) The amount of coagulant to be injected can be determined intermittently by a jar test, and a rapid index can be used between jar tests to make corrections according to fluctuations in raw water properties.This has the effect of (ii) suppressing fluctuations in treated water turbidity. (iii) It also has the effect of reducing the amount of coagulant to be injected.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram showing a flocculant-sedimentation treatment apparatus in which flocculant injection control is executed according to the first embodiment of the flocculant injection control method according to the present invention, and FIG. FIG. 3 is an enlarged sectional view showing a part of the coagulation and sedimentation processing apparatus shown in FIG. A conceptual diagram showing a flocculating sedimentation processing apparatus in which flocculant injection control is executed according to the second embodiment of the flocculant injection control method according to the present invention, FIGS. An operation explanatory diagram for explaining a specific example of the embodiment, FIG. 6 is a coagulation-sedimentation process in which flocculant injection control is executed according to the third embodiment of the flocculant injection control method according to the present invention. Conceptual diagram to show the device, Figure 7a-
d is an operation explanatory diagram for explaining a specific example of the embodiment shown in FIG. 6, and FIG. 9A to 9D are operational explanatory diagrams for explaining a specific example of the embodiment in FIG. 8, and FIG. 10 is a flocculant injection control method according to the present invention. A conceptual diagram showing a coagulation and sedimentation processing apparatus in which injection control of a coagulant is executed according to the fifth embodiment of the present invention, Fig. 11a-
d is an operation explanatory diagram for explaining a specific example of the embodiment shown in FIG. 10, and FIG. 12 is a diagram illustrating a flowchart in which the injection control of the flocculant is executed according to the sixth embodiment of the flocculant injection control method according to the present invention. 13A to 13D are operational explanatory diagrams for explaining a specific example of the embodiment shown in FIG. 12, and FIG. 14 is a flocculant injection control method according to the present invention. 1 is a conceptual diagram showing a coagulation sedimentation processing apparatus in which injection control of a coagulant is executed according to the seventh embodiment of the present invention;
5A to 5D are operation explanatory diagrams for explaining a specific example of the embodiment in FIG. 14. 10 ... Coagulation sedimentation processing device, 11A, 11B...
... Raw water supply pipe, 11C... Treated water discharge pipe, 12...
...Water landing well, 13... Rapid stirring pond, 13A... Drive source, 13B... Stirring member, 14... Slow stirring pond,
14A... Drive source, 14B... Stirring member, 15...
...Sedimentation tank, 16...Flocculant injection device, 16A...
Coagulant storage tank, 16B...Measuring pump, 17...Raw water PH meter, 17A...Raw water thermometer, 17B...Raw water turbidity meter, 18...Jear test device, 18a...
Water sampling pipe, 18a ⁺ ...Water sampling pump, 18b...
...Drainage pipe, 19 ...Flowing ammeter, 19a, 1
9a ^* , 19a ^** ... Water sampling pipe, 19a ⁺ ... Water sampling pump, 19b ... Drainage pipe, 19c, 19d
... Connection wire, 19A ... Cylindrical container, 19B, 19
C... Electrode, 19D... Power source, 19E... Piston, 19F... Ammeter, 20... Treated water turbidity meter, 21... Setting device, 22... Arithmetic device, 23
... Comparison circuit, 24 ... Control device, 29 ... Coagulation dispersion analyzer, 39 ... Zeta electrometer, 49 ... Colloid charge amount measuring device, 59 ... Image analysis device, 6
9...Pilot filter.

Claims (1)

[Claims] 1. When a flocculant is injected into raw water in order to flocculate suspended solids from the raw water, remove precipitates, and discharge as treated water, the amount of flocculant injected is controlled according to the properties of the raw water. A coagulant injection control method consisting of (a) a first step of intermittently detecting the optimum injection amount of a coagulant into raw water using a jar test; (b) a first step in which the optimum injection amount of a coagulant is detected in the first step. (c) a second step of determining the amount of coagulant to be injected into the raw water according to the optimum injected amount of the coagulant detected in the first step; a third step of injecting the flocculant into the raw water according to the amount of flocculant determined in the second step when the amount is detected; (d) injecting the flocculant in the third step; (e) a fifth step of holding the measured value of the flowing current measured in the fourth step as a target value of the flowing current; (f) ) a sixth step of injecting a flocculant into the raw water after the third step; (g) a seventh step of measuring the flowing current of the raw water into which the flocculant was injected in the sixth step; (h ) an eighth step of comparing the target value of the flowing current held in the fifth step and the measured value of the flowing current measured in the seventh step; (i) the results compared in the eighth step; A ninth step of correcting the amount of injection of the flocculant determined in the second step according to the amount of injection of the flocculant in the sixth step and determining the amount of injection of the flocculant in the sixth step. Control method. 2. Coagulant injection control that controls the injection amount of coagulant according to the properties of raw water when coagulant is injected into raw water in order to coagulate suspended solids from raw water, remove precipitates, and discharge as treated water. The method includes (a) a first step of intermittently detecting the optimal injection amount of a flocculant into raw water using a jar test; (b) a second step of measuring flowing current of the raw water; and (c) a first step. (d) when the optimum injection amount of the coagulant is detected in the step, the injection amount of the coagulant to the raw water is determined according to the optimum injection amount of the coagulant detected in the first step; a fourth step of injecting the flocculant into the raw water according to the flocculant injection amount determined in the third step when the optimal injection amount of the flocculant is detected in the first step; ) A fifth step of measuring the flowing current of the raw water into which the flocculant was injected in the fourth step; A sixth step of calculating the measured value of the flowing current difference by subtracting the measured value of the flowing current.
(g) A seventh step for holding the measured value of the flowing current difference calculated in the sixth step as a target value of the flowing current difference; (h) After the fourth step, the raw water is On the other hand, the eighth step of injecting the flocculant, (i) the ninth step of measuring the flowing current of the raw water into which the flocculant was injected in the eighth step, and (j) the flow current measured in the second step. A tenth step of calculating the measured value of the flowing current difference by subtracting the measured value of the flowing current measured in the ninth step from the measured value of the flowing current.
(k) an eleventh step of comparing the target value of the flowing current difference held in the seventh step and the measured value of the flowing current difference calculated in the tenth step; A 12th step of determining the amount of coagulant to be injected in the 8th step according to the results compared in the 11th step. 3. Coagulant injection control that controls the injection amount of coagulant according to the properties of raw water when coagulant is injected into raw water in order to coagulate suspended solids from raw water, remove precipitates, and discharge as treated water. In the method, (a) a first step of intermittently detecting the optimum injection amount of a flocculant with respect to raw water using a jar test; (b) when the optimum injection amount of a coagulant is detected in the first step, a first step of (c) when the optimum injection amount of the coagulant is detected in the first step; (c) when the optimum injection amount of the coagulant is detected in the first step; , a third step of injecting a flocculant into the raw water according to the injection amount of the flocculant determined in the second step, and (d) coagulation and dispersion of the raw water into which the flocculant was injected in the third step. a fourth step of analyzing the state; (e) a fifth step of holding the analytical value of the agglomerated dispersion state analyzed in the fourth step as a target value of the agglomerated dispersion state; and (f) a third step. (g) a seventh step of analyzing the state of coagulation and dispersion of the raw water into which the coagulant was injected in the sixth step; (h) a sixth step of injecting a flocculant into the raw water after the step of an eighth step of comparing the target value of the agglomerated dispersion state maintained in step 5 with the analytical value of the agglomerated dispersion state measured in the seventh step; (i) the results compared in the eighth step; a ninth step of determining the amount of coagulant to be injected in the sixth step according to the amount of coagulant injection. 4. Coagulant injection control that controls the injection amount of coagulant according to the properties of raw water when coagulant is injected into raw water in order to coagulate suspended solids from raw water, remove precipitates, and discharge as treated water. In the method, (a) a first step of intermittently detecting the optimum injection amount of a flocculant with respect to raw water using a jar test; (b) when the optimum injection amount of a coagulant is detected in the first step, a first step of (c) when the optimum injection amount of the coagulant is detected in the first step; (c) when the optimum injection amount of the coagulant is detected in the first step; (d) a third step of injecting the coagulant into the raw water according to the injection amount of the coagulant determined in the second step; a fourth step of measuring the zeta potential of the aggregate; (e) a fifth step of holding the measured value of the zeta potential measured in the fourth step as a target value of the zeta potential; (g) a seventh step of measuring the zeta potential of aggregates in the raw water into which the coagulant was injected in the sixth step; (h) an eighth step of comparing the target value of zeta potential held in the fifth step and the measured value of zeta potential measured in the seventh step; a ninth step of determining the amount of coagulant to be injected in the sixth step according to the result of the coagulant injection control method. 5. Coagulant injection control that controls the injection amount of coagulant according to the properties of raw water when coagulant is injected into raw water in order to coagulate suspended solids from raw water, remove precipitates, and discharge as treated water. In the method, (a) a first step of intermittently detecting the optimum injection amount of a flocculant with respect to raw water using a jar test; (b) when the optimum injection amount of a coagulant is detected in the first step, a first step of (c) when the optimum injection amount of the coagulant is detected in the first step; (c) when the optimum injection amount of the coagulant is detected in the first step; , a third step of injecting a flocculant into the raw water according to the injection amount of the flocculant determined in the second step, and (d) colloidal charge of the raw water into which the flocculant was injected in the third step. (e) a fifth step for holding the measured value of the amount of colloid charge measured in the fourth step as a target value of the amount of colloid charge; (f) a third step. (g) a seventh step of measuring the colloidal charge amount of the raw water into which the coagulant has been injected in the sixth step; (h) a seventh step of injecting a coagulant into the raw water after the step of an eighth step of comparing the target value of the amount of colloid charge held in step 5 with the measured value of the amount of colloid charge measured in the seventh step; (i) the results compared in the eighth step; a ninth step of determining the amount of coagulant to be injected in the sixth step according to the amount of coagulant injection. 6. Coagulant injection control that controls the injection amount of coagulant according to the properties of raw water when coagulant is injected into raw water in order to coagulate suspended solids from raw water, remove precipitates, and discharge as treated water. In the method, (a) a first step of intermittently detecting the optimum injection amount of a flocculant with respect to raw water using a jar test; (b) when the optimum injection amount of a coagulant is detected in the first step, a first step of (c) when the optimum injection amount of the coagulant is detected in the first step; (c) when the optimum injection amount of the coagulant is detected in the first step; (d) a third step of injecting the coagulant into the raw water according to the injection amount of the coagulant determined in the second step; a fourth step of measuring at least one of the geometric mean diameter, number, and average effective density of the aggregates; (e) measuring the geometric mean diameter, number, and average effective density of the aggregates measured in the fourth step; (f) retaining at least one of the measured values as a target value of at least one of the geometric mean diameter, number and mean effective density of the aggregates; (g) measuring at least one of the geometric mean diameter, number, and average effective density of aggregates in the raw water into which the flocculant has been injected in the sixth step; a seventh step; (h) a target value of at least one of the geometric mean diameter, number, and average effective density of the aggregates retained in the fifth step and the geometry of the aggregates measured in the seventh step; An eighth step of comparing the measured value with at least one of the average diameter, the number, and the average effective density.
and (i) a sixth step of determining the amount of coagulant to be injected in the sixth step according to the results compared in the eighth step. Method. 7. Coagulant injection control that controls the injection amount of coagulant according to the properties of raw water when coagulant is injected into raw water in order to coagulate suspended solids from raw water, remove precipitates, and discharge as treated water. In the method, (a) a first step of intermittently detecting the optimum injection amount of a flocculant with respect to raw water using a jar test; (b) when the optimum injection amount of a coagulant is detected in the first step, a first step of (c) when the optimum injection amount of the coagulant is detected in the first step; (c) when the optimum injection amount of the coagulant is detected in the first step; , a third step of injecting a flocculant into the raw water according to the injection amount of the flocculant determined in the second step; (d) a pilot filter for the raw water into which the flocculant was injected in the third step; (e) a fifth step for holding the measured value of the head loss rise speed measured in the fourth step as a target value of the head loss rise speed; , (f) a sixth step of injecting a flocculant into the raw water after the third step, and (g) measuring the head loss rate at the pilot filter of the raw water into which the flocculant has been injected in the sixth step. (h) an eighth step of comparing the target value of the head loss rise rate held in the fifth step with the measured value of the head loss rise rate measured in the seventh step; (i) A ninth step of determining the amount of coagulant to be injected in the sixth step according to the results compared in the eighth step.