TW201838701A - Method for controlling injection of flocculant, control device, and water treatment system - Google Patents

Abstract

A method for controlling the injection of a flocculant in a water treatment system in which a cationic polymer flocculant and an inorganic flocculant are added to treatment water and solid-liquid separation is performed, wherein the method for controlling the injection of a flocculant is characterized in that: the flow potential of the treatment water, or of flocculant-treated water to which a flocculant has been added, is measured; the addition amounts of the cationic polymer flocculant and the inorganic flocculant are determined on the basis of the measured flow potential; and the cationic polymer flocculant and the inorganic flocculant are added in the determined amounts.

Description

Aggregate injection control method, control device and water treatment system

[0001] The present invention relates to a method and apparatus for controlling an optimum agglutination amount of a cationic polymer and an inorganic aggregating agent when aggregating various industrial drainage or industrial water or the like. Furthermore, the invention relates to a water treatment system having such a control device.

[0002] In various pretreatments of drainage/water, an agglutination treatment is used to remove turbidity and organic matter. In the aggregating agent used for the agglutination treatment, an iron-based aggregating agent such as ferric chloride or polyaluminum chloride or an aluminum-based inorganic aggregating agent is generally used, but agglomeration using a cationic polymer flocculating agent and an inorganic aggregating agent is also performed. deal with. By using these two kinds of chemicals, in addition to the coarsening of the aggregates and the easy completion of the solid-liquid separation operation in the latter stage, the amount of sludge generated by suppressing the addition amount of the inorganic flocculant can be reduced (Patent Document 1) 2). [0003] The amount of the aggregating agent to be added must be added in an appropriate amount depending on the quality of the water to be treated. If the amount of the drug is insufficient, the removal of the turbid substance or the organic substance contained in the water to be treated becomes insufficient, and the treated water quality deteriorates. On the other hand, if the amount of the drug is excessive, the drug leaks to the subsequent stage, and there is a possibility that the load to be treated in the latter stage is increased or contaminated. [0004] In order to determine the optimum amount of medicine, the bottle test is generally carried out, but it requires a large amount of labor. When the water quality of the water to be treated is changed, the bottle test is performed, and in actual water treatment, it is not practical to respond to the change immediately. In the automatic control of the amount of the aggregating agent to be injected, control is performed based on the specific water quality of the water to be treated, such as turbidity or organic matter concentration (Patent Documents 3 and 4). In addition, a method of controlling the amount of aggregating agent injection by using the value of the flow current meter of the agglomerated water is proposed (Patent Document 5). [0005] The agglutination reaction is generally promoted by the charge neutralization by the use of a coagulant, and therefore, the measurement is based on the use of an interface electrokinetic phenomenon using a flow potential (flow current) and a zeta potential, and is focused on a specific water quality. Compared with the control of the project, it is expected that the controller can be applied to the treated water for a larger range. [Patent Document 1] Japanese Patent No. 2,938, 270 [Patent Document 2] Japanese Patent No. 6028826 [Patent Document 3] Japanese Patent No. 4746835 [Patent Document 4] Japanese Patent No. 5103747 [Patent Document 5] Japanese Patent In the control of Patent Documents 1 to 3, the drug to be added in an amount-controlled manner is limited to one type, and in the two-agent addition treatment of two types of drugs using a cationic polymer flocculating agent and an inorganic aggregating agent in combination, It is not possible to calculate the optimum amount of each drug to be added.

(Problem to be Solved by the Invention) [0008] An object of the present invention is to provide a system (two-agent addition treatment) in which two kinds of drugs, which are a cationic polymer and an inorganic aggregating agent, are added as a coagulant to a water to be treated, A method and apparatus for appropriately controlling the amount of two types of medicines to be separately controlled. (Means for Solving the Problem) [0009] The gist of the present invention is as follows. [1] A method for controlling aggregating agent injection, which is a method for controlling aggregating agent injection in a water treatment system in which a cationic polymer aggregating agent and an inorganic aggregating agent are added to a treated water, and solid-liquid separation is performed, and the characteristics thereof are characterized. The flow potential of the water to be treated or the agglomerated water to which the aggregating agent is added is measured, and the amount of the cationic polymer flocculating agent and the inorganic aggregating agent added is determined based on the measured flow potential value, and the addition amount is obtained by the addition. A cationic polymer flocculant and an inorganic aggregating agent are added in an amount. [2] The method for controlling aggregating agent injection according to [1], wherein the difference between the optimum value of the flow potential value of the agglomerated water and the flow potential value of the actual agglomerated water is obtained by a prior test. Insufficient concentration A of the inorganic aggregating agent, the amount of the inorganic aggregating agent added is a·A, and the amount of the cationic polymer aggregating agent added is b·A, where a=0.1 to 0.9 b=0.001 to 0.008. [3] The agglutination agent injection control method according to [2], wherein, in order to correct an error of a flow potential value of the aggregated treated water to be measured, before or after the measurement of the flow potential value of the aggregated treated water, The flow potential of the standard solution is measured, and the flow potential value of the actual agglutination treatment water is corrected according to the flow potential value of the standard solution to obtain a correction value, and the difference between the optimum value of the flow potential value of the agglutination treatment water and the correction value is calculated. Insufficient concentration A of the aggregating agent. . [4] The method for controlling aggregating agent injection according to [3], wherein the following formula is corrected. E2=E1×(R2/R1) where E1: the flow potential value of the agglutination treatment water (measured value) [mV] E2: the flow potential value of the agglutination treatment water (correction value) [mV] R1: standard solution The value of the flow potential (at the time of the bench test evaluation) [mV] R2: The flow potential value of the standard solution (before or after the measurement of the flow potential of the agglutination treatment water) [mV] [0015] [5] As in [1] The agglutination agent injection control method is characterized in that a part of the agglutination-treated water is sampled in a measurement container to measure a flow potential, and a titration is performed to measure a cationicity required for the measured flow potential value to be negative until a value of 0 is displayed. The addition amount B of the polymer aggregating agent is c·B, and the additional addition amount of the inorganic aggregating agent is d·B, wherein c=0.1 to 0.9 d=5 ～ 90. [6] The aggregating agent injection control method according to [1], wherein the water to be treated is sampled in the measurement container, and the measured flow potential value is measured by titration until the value of 0 is displayed. The amount C of the cationic polymer flocculating agent required is set to e·C, and the amount of the inorganic aggregating agent is f·C, where e=0.1 to 0.9 f =5 to 90. [7] A flocculant injection control device which is a flocculant injection control device in a water treatment system in which a cationic polymer aggregating agent and an inorganic aggregating agent are added to a treated water and subjected to solid-liquid separation, and is characterized by And a flow potentiometer for measuring a flow potential of the water to be treated or the agglomerated water to which the aggregating agent is added; and determining the cationic polymer aggregating agent and the inorganic aggregating agent based on the measured value of the flow potentiometer The means of calculating the amount of addition. [8] The aggregating agent injection control device according to [7], wherein the calculation means includes: an optimum value of a flow potential value of the aggregated treated water obtained by a prior test, and a measured value of the control flow potential The difference is the means for determining the insufficient concentration A of the inorganic aggregating agent; and the means for adding the inorganic aggregating agent to a·A, and the amount of the cationic polymer aggregating agent to be added is b·A. [9] The aggregating agent injection control device according to [8], wherein the calculating means includes: a measuring means for measuring a flow potential of the standard solution before or after the measurement of the flow potential value of the agglomerated water; a means for obtaining a correction value of the flow potential value of the agglutination treatment water to be measured, and a difference between the optimum value of the flow potential value of the agglutination treatment water and the correction value, and calculating the deficiency of the inorganic aggregating agent The means of concentration A. [10] The aggregating agent injection control device according to [7], further comprising: a measurement container that houses a part of the agglutination water; a flow potentiometer provided in the measurement container; and the measurement is performed by titration The means for calculating the amount of the cationic polymer flocculating agent required for the measurement of the flow potentiometer from the negative to the value of 0; and calculating the additional amount of the cationic polymer flocculating agent to be c·B, and calculating the inorganic The additional amount of the aggregating agent is a means of d·B, wherein c = 0.1 to 0.9 d = 5 to 90. [11] The aggregating agent injection control device according to [7], further comprising: a measurement container that accommodates a part of the water to be treated; the flow potentiometer provided in the measurement container; and the measurement by titration The measurement value of the flow potentiometer is a means for reducing the amount C of the cationic polymer required until the value of 0 is displayed; and the amount of addition of the cationic polymer flocculating agent is calculated as e·C, and the inorganic aggregating agent is calculated. The amount of addition is f·C, where e=0.1 to 0.9 f=5 to 90. [12] The aggregating agent injection control device according to any one of [7] to [11], wherein the light scattering type fine particle sensation is provided to measure turbidity in a void between the coagulated particles in the agglutination treatment water. Detector or light-interrupting particle sensor. [13] A water treatment system comprising the aggregating agent injection control device according to any one of [7] to [12], wherein: the method comprises: performing a solid-liquid treatment of the agglutination treatment water Separation of solid-liquid separation means. [14] The water treatment system according to [13], wherein: the method for measuring an ORP value of the water to be treated; and the method of adding an oxidizing agent to the water to be treated so that the ORP value of the water to be treated is 300 mV or more Add means. (Effect of the Invention) According to the present invention, in the two-agent addition treatment of two types of aggregating agents in which a cationic polymer flocculating agent and an inorganic aggregating agent are added to the water to be treated, even if the water quality of the water to be treated is changed, In this case, an appropriate addition amount of each aggregating agent can also be calculated to prevent contamination of the subsequent stage treatment due to poor aggregation.

[0027] Hereinafter, embodiments will be described with reference to the drawings. 1 is a configuration diagram showing a control device according to a first embodiment. The raw water is introduced into the raw water tank 1 and, if necessary, the oxidizing agent is added so that the ORP is 300 mV or more by the ORP meter 2 and the raw water tank medicine injection control device 4 provided in the raw water tank 1. As the oxidizing agent, a hypochlorite or a chlorine dioxide compound can be used. [0029] When the pH must be adjusted to be constant before the addition of the aggregating agent, the pH meter 3 may be provided in the raw water tank 1, and the pH adjusting tank 1a may be provided in the front stage of the raw water tank 1. As the pH adjuster, sodium hydroxide, slaked lime, hydrochloric acid, sulfuric acid or the like can be used. [0030] The raw water system in the raw water tank 1 is then introduced into the condensation tank 5, and a part thereof is introduced into a sampling cell 6. In the sampling tank 6, a predetermined volume of raw water is sealed, and the titration device 7 performs titration by the cationic polymer flocculant solution, whereby the measured value of the flow potentiometer 8 can be measured from negative to a value of 0. The concentration (addition amount) of the cationic polymer flocculant required until then. In the above, it is preferable to use a stopped flow method in which the valve 9 attached to the raw water side of the sampling tank 6 is temporarily stopped after the raw water is passed through the sampling tank 6 for a predetermined period of time before the titration is performed. The cationic polymer flocculating agent used for the titration is preferably the same as the cationic polymer aggregating agent used as the aggregating agent. [0032] It is preferable to introduce the cleaning liquid into the sampling tank 6 so that the measuring portion of the flow potentiometer 8 and the sampling tank 6 can be periodically washed. In the case of the washing liquid, one or two or more kinds of an acid, a base, and an oxidizing agent are preferably used depending on the water quality of the water to be treated. In the coagulation tank 5, in addition to the two types of the cationic polymer flocculating agent and the inorganic aggregating agent, a pH adjustment for adjusting the pH of the agglutination water to be constant is added by the coagulant injection control device 10. Agent. [0034] Examples of the cationic polymer flocculating agent used include poly(diallyldimethylammonium chloride), poly(2-dimethylaminoethyl methacrylate), and poly Dimethylaminoethyl methacrylate benzyl quaternary salt, polyethylenimine, polyallylamine, polyvinylamine, poly(2-dimethylaminoethyl methacrylate) ), poly(2-vinyl-1-methylpyridinium), dialkylamine-epichlorohydrin polycondensate, polylysine, chitosan, diethylaminoethylpolydextrose, and the like. Examples of the inorganic aggregating agent include iron-based inorganic aggregating agents such as ferric chloride, ferric sulfate, polyferric chloride, and polyferric sulfate; or aluminum chloride, polyaluminum chloride, aluminum sulfate, aluminum hydroxide, and oxidation. Aluminum-based inorganic aggregating agent such as aluminum. A mixture of two or more types of cationic polymer flocculating agents may be used as the aggregating agent, or a mixture of two or more types of inorganic aggregating agents may be used as the inorganic aggregating agent. The addition amount of the cationic polymer flocculating agent and the inorganic aggregating agent is calculated from the concentration of the cationic polymer flocculating agent determined by the above-described titration (details will be described later). The cationic polymer flocculating agent and the inorganic aggregating agent may be added to the individual aggregation tanks 5 and 11 as shown in the drawing, or may be added to the same aggregation tank although not shown. Regarding the order of addition, either one may be added first or both. [0036] The pH adjuster is added so that the pH in the aggregation tank 11 detected by the pH meter 12 becomes a predetermined pH. [0037] The agglutination treatment water in the aggregating tank 5 is then introduced into the agglutination sensor tank 13. The aggregating sensor tank 13 is provided with a fine particle sensor 14. In the microparticle sensor 14, a light scattering type including an illuminator for measuring the turbidity of the condensed particles, an illuminator for radiating the laser light, and a probe for detecting the scattered laser light can be used. A microparticle sensor (for example, those described in Japanese Patent No. 3925621) or a photo-interrupting microparticle sensor or the like. [0038] If the turbidity of the voids of the agglomerated particles measured by the fine particle sensor 14 is increased, it is considered that the amount of the addition of the two agents of the aggregating agent with respect to the water quality is insufficient or excessive, or the cationic polymer aggregating agent The agglutination failure occurs for some reason that the ratio of the amount of the inorganic aggregating agent added is inappropriate. The automatic adjustment of the amount of the aggregating agent added according to the measured value of the flow potentiometer 8 may be set at a time interval, or/and the turbidity of the void of the condensed group particles measured by the microparticle sensor 14 may be used. Set the way to implement when rising. [0040] The agglutination treatment water in the aggregating sensor tank 13 is sent to the solid-liquid separation processing device through the treatment water pump 15. Examples of the solid-liquid separation treatment include a membrane separation treatment, a sand filtration treatment, a precipitation treatment, and a pressurized floating treatment. The method of calculating the amount of addition of the cationic polymer flocculating agent and the inorganic aggregating agent by the titration value obtained by the flow potentiometer 8 can be obtained, for example, from the results shown in FIG. 2 . 2 is a titration curve showing an example of the relationship between the concentration of the cationic polymer flocculating agent and the flow potential value. For example, the concentration (C) required for charge neutralization is a concentration of a cationic polymer flocculant (here, about 5 mg/L) when the flow potential value reaches 0 mV. [0043] The amount of the inorganic aggregating agent to be added depends on the water quality of the water to be treated and the type of the inorganic aggregating agent to be used, but is more than C, preferably 5 to 90 times C (that is, C). It is preferable to adjust the setting in the range of ×5 to C × 90), particularly in the range of 10 to 50 times. The amount of the cationic polymer flocculating agent to be added depends on the water quality of the water to be treated and the type of the cationic polymer flocculating agent to be used, but is less than C, and preferably 0.1 to 0.9 times C (see C). That is, it is preferable to adjust the setting in a range of C × 0.1 to C × 0.9), particularly 0.5 to 0.9 times. 3 is a schematic view showing a configuration of a coagulant injection control device according to another embodiment of the present invention. [0045] The control device of FIG. 3 changes the feedforward control of FIG. 1 to a feedback controller. That is, the sampling tank 6 accommodates a part of the agglomerated water from the aggregating sensor tank 13 so as to return the measured water to the aggregating sensor tank 13. [0046] A flow potentiometer 8 is provided in the sampling tank 6. By using the titration of the same cationic polymer flocculating agent as described above, it is possible to measure an insufficient amount of agglutination which is insufficient from the current amount of drug injection. The sampling tank 6 may be provided to introduce the agglomerated treated water from the collecting tank 11, or may be provided in the latter stage of the solid-liquid separating apparatus to introduce the solid-liquid separating treated water. [0047] The amount of additional addition of the inorganic aggregating agent to the required amount of titration (B) from the charge obtained by the flow potentiometer 8 depends on the quality of the water to be treated and the type of inorganic aggregating agent used. It is preferable to adjust and set the ratio B to be more than 5 to 90 times (i.e., B × 5 to B × 90), preferably in the range of 10 to 50 times B. Further, the additional amount of the cationic polymer flocculating agent depends on the water quality of the water to be treated and the type of the cationic polymer flocculating agent to be used, but it is less than B, and preferably 0.1 to B. It is preferable to adjust and set 0.9 times (that is, B × 0.1 to B × 0.9), preferably in the range of 0.5 to 0.9 times B. [0048] Depending on the water quality of the water to be treated, if the titration value of B is less than 0.1 mg/L, the addition amount of the cationic polymer flocculating agent and the inorganic aggregating agent is in the range of 5% or less. It is advisable to set the method of reduction. 4 is a diagram showing a control device of still another embodiment. In the control device of Fig. 4, the titration device which is not in the sampling tank 6 in the configuration of Fig. 3 must determine the optimum value of the flow potential value of the aggregating treated water by the prior evaluation. In FIG. 4, as in the case of FIG. 3, the sampling tank 6 is provided so that the aggregating treatment water is accommodated by the aggregating sensor tank 13, but the sampling tank 6 may be introduced by the aggregating tank 11 as in the case of FIG. The agglutination treatment water may be provided in the latter stage of the solid-liquid separation device to introduce the solid-liquid separation treatment water. In addition, when introducing the solid-liquid separation treatment water, it is necessary to determine the optimum value of the flow potential value of the solid-liquid separation treatment water by the prior evaluation. [0050] The optimum value of the flow potential value of the agglutination treated water can be determined from the results shown in FIG. 5, for example, to obtain an optimum value. 5 is a graph showing the relationship between the amount of addition of the inorganic aggregating agent and the flow potential value and the quality of the agglomerated treated water, which are evaluated by the previous workbench test, and the water quality of the agglomerated treated water is expressed by the MFF value. The method of measuring the MFF value is as follows. The MF membrane was set in the suction filtration device, and the first time water time T1 of the measurement sample (150 mL) was measured after measuring the permeation time T0 of the soluble polymer substance and the reference water having no fine particles of 150 mL under a reduced pressure of -67 kPa. The second water passing time T2. MFF value = T2 / T1. When the value of MFF is good, the flow potential shows a specific value which is an optimum value (here, about -300 mV) of the flow potential value of the agglomerated water. The correlation diagram between the amount of the inorganic aggregating agent added and the flow potential value as described above is recorded in the aggregation control device, and the inorganic aggregating agent concentration and the flowing potential value indicated by the actual potential value of the agglomerated treated water are optimally set. The difference in the concentration of the agent (here, about 200 mg/L) was used to calculate the insufficient concentration (A) of the inorganic aggregating agent. The additional addition amount of the inorganic aggregating agent depends on the water quality of the water to be treated and the type of the inorganic aggregating agent to be used, but it is 0.1 to 0.9 times of A (that is, A × 0.1 to A × 0.9). It is preferable to adjust and set the mode within a range of 0.2 to 0.5 times of A. In addition, the amount of addition of the cationic polymer flocculant depends on the water quality of the water to be treated and the type of the cationic polymer flocculating agent to be used, and is 0.001 to 0.008 times A (that is, A × 0.001 to A). It is preferable to adjust the setting of ×0.008), preferably in the range of 0.005 to 0.008 times of A. When the flow potential value of the actual aggregating treated water is higher than the optimum value of the flowing potential value of the aggregating treated water, the cationic polymer flocculating agent is likely to be excessive, so the amount of the aggregating agent must be added. Re-evaluation of the set value. [0056] A problem in the on-line measurement of the flow potentiometer 8 in the configuration of FIG. 4 is that the measurement portion of the flow potentiometer 8 is dirty due to turbidity or organic matter contained in the water to be treated, an added aggregating agent, or the like. The absolute value of the flow potential value cannot be measured correctly. Although the method of washing every measurement is considered, the problem that the consumption of the cleaning liquid is increased and the measurement cannot be performed during the cleaning is newly caused. [0057] In order to solve this problem, a method of measuring the flow potential value of the standard liquid and correcting the measured value is shown below. In the standard solution, in order to impart electrical conductivity, a solution in which a low-concentration salt or a pH buffer is dissolved may be used, and a dispersion of polystyrene latex particles or vermiculite particles or the like may be added. The size of the particles is preferably colloidal particles having a particle diameter of several hundred nm or less, so that particle deposition does not occur. [0058] The conversion formula for the correction is as follows. E2=E1×(R2/R1) E1: Flow potential value of agglutination treated water (measured value) [mV] E2: Flow potential value of agglutination treated water (correction value) [mV] R1: Flow potential value of standard solution ( [mV] R2: Flow potential value of standard solution (before or after measurement of flow potential of agglutination treatment water) [mV] [Examples] [Test method] In the following examples The test water to be used and the reagents used in the comparative examples are as follows. Test treated water: biologically treated water for factory drainage (ORP: 100-200 mV) Cationic polymer: poly(diallyldimethylammonium chloride) Inorganic aggregating agent: ferric chloride (38%) Oxidizer: Sodium hypochlorite [Example 1] In the configuration of the aggregating agent injection control system shown in Fig. 1, an oxidizing agent is added to the raw water tank so that the ORP of the raw water tank is in the range of 325 ± 25 mV, and the amount of the aggregating agent is automatically added. The adjustment value was set as follows: Cationic polymer: C × 0.8 [mg / L] Inorganic aggregating agent: C × 8 [mg / L] The agglutination treatment was carried out. The change with time of the MFF value of the obtained agglomerated water was measured. [Comparative Example 1] In the system configuration shown in Fig. 1, the amount of addition of the cationic polymer was 0.5 mg/L, and the amount of the inorganic aggregating agent was formed without performing automatic adjustment of the amount of addition of the aggregating agent. A quantitative injection of 50 mg/L. Others are the same as in the first embodiment. The results of Example 1 and Comparative Example 1 are shown in FIG. 6. The water content of the water to be treated due to the passage of time was changed, and the C value of the drip amount also changed in the same manner. In Comparative Example 1, the water quality of the agglomeration treatment deteriorated together with the fluctuation of the water quality. On the other hand, in Example 1, the amount of addition of the two types of aggregating agents was automatically adjusted based on the C value, and thus the water quality of the agglutination treatment was hardly deteriorated and did not change. [Embodiment 2] In the system configuration shown in Fig. 1, an oxidizing agent is added to the raw water tank so that the ORP of the raw water tank is in the range of 325 ± 25 mV, and the setting value of the automatic adjustment value of the amount of the aggregating agent added is set. Formed as: Cationic polymer: C × 0.2 [mg / L] Inorganic aggregating agent: C × 30 [mg / L] to carry out agglutination treatment. Further, membrane separation treatment (PVDF, pore diameter: 0.02 μm, operating conditions: operating Flux (flux) 4 m/D, backwashing interval: 28 min) was carried out, and the rate of increase in the differential pressure between membranes was measured as a solid-liquid separation treatment in the latter stage of the system. . [Comparative Example 2] In the system configuration shown in Fig. 1, an oxidizing agent was not added to the raw water tank, and aggregation treatment was performed. Others are the same as in the second embodiment. The results of Example 2 and Comparative Example 2 are shown in Table 1. In Example 2, the C value was lower than that of Comparative Example 2 by adding an oxidizing agent to the raw water tank. This is considered to be due to the deterioration of the treated water. Further, the rate of increase in differential pressure was lower in Example 2, and it was found that good agglomeration treated water was obtained. From this, it is clear that even if a flow potentiometer is used to automatically adjust the amount of addition of the two types of agents, if the ORP of the raw water tank is not adjusted to a certain value or more, the aggregation control cannot be sufficiently performed. [Table 1] [Example 3] The membrane separation treatment (PVDF, pore diameter 0.02 μm, operating conditions: operating Flux 2 to 4 m/D, backwashing interval 10 to 28 min) was carried out in the system configuration shown in Fig. 1 as the latter stage of the system. Solid-liquid separation treatment. Further, the turbidity (inter-aggregate turbidity) of the voids of the coagulating particles in the agglomerated water in the continuous flowing water and the differential pressure between the membranes are measured by the light-scattering microparticle sensor provided in the aggregating sensor tank. The relationship between the rate of rise. The results are shown in FIG. It can be seen that if the turbidity between the agglomerates increases, the rate of increase in the differential pressure also becomes high, and a strong correlation is found. The increase in the turbidity between the agglomerates is considered to be due to the fact that the water quality of the treated water changes rapidly and the aggregation is poor, or the water quality of the treated water greatly changes, and the value measured by the flow potentiometer (A, B, The adjustment of the automatic addition amount of the two types of aggregating agents of the type C is not appropriate. Therefore, when the turbidity between the agglomerates increases to a certain value or more, a method of setting the method of automatically adjusting the amount of the aggregating agent added by the measurement of the flow potentiometer or agglutination of two types is considered. The method of adjusting the automatic addition amount of the agent to the new value is reset. As described above, it can be utilized as an alarm sensor for confirming whether or not aggregation failure has occurred by the particle sensor provided in the aggregating sensor tank. The present invention has been described in detail with reference to the particular embodiments of the invention, and various modifications thereof may be made without departing from the spirit and scope of the invention. The present application is based on Japanese Patent Application No. 2017-047570, filed on Mar.

[0071]

1‧‧‧ original sink

1a‧‧‧pH adjustment tank

2‧‧‧ORP meter

3, 12‧‧‧ pH meter

4‧‧‧ Raw water tank medicine injection control device

5, 11‧‧‧ agglutination tank

6‧‧‧Sampling tank

7‧‧‧Titration device

8‧‧‧Flow potentiometer

9‧‧‧ valve

10‧‧‧ agglutination agent injection control device

13‧‧‧Aggregation sensor slot

14‧‧‧Microparticle sensor

15‧‧‧Processing water pump

1 is a configuration diagram of a coagulant injection control device according to an embodiment of the present invention. Figure 2 is a graph showing the results of the experiment. Fig. 3 is a configuration diagram of a coagulant injection control device according to an embodiment of the present invention. Fig. 4 is a configuration diagram of a coagulant injection control device according to an embodiment of the present invention. Figure 5 is a graph showing the results of the experiment. Figure 6 is a graph showing the results of the experiment. Figure 7 is a graph showing the results of the experiment.

Claims (14)

A method for controlling agglutination agent injection, which is a method for controlling agglutination agent injection in a water treatment system in which a cationic polymer aggregating agent and an inorganic aggregating agent are added to a treated water and subjected to solid-liquid separation, wherein: the treated water is measured Or a flow potential of the agglomerated water to which the aggregating agent is added, and the amount of the cationic polymer flocculating agent and the inorganic aggregating agent added is determined based on the measured flow potential value, and the cationic polymer is added in the added amount. Aggregating agent and inorganic aggregating agent. The method for controlling aggregating agent injection according to the first aspect of the patent application, wherein the inorganic aggregating agent is obtained from a difference between an optimum value of a flow potential value of the agglomerated water and a flow potential value of the actual agglomerated water by an ex ante test In the case of the insufficient concentration A, the amount of the inorganic aggregating agent added is a·A, and the amount of the cationic polymer aggregating agent added is b·A, wherein a=0.1 to 0.9 b=0.001 to 0.008. In the method of controlling aggregating agent injection according to the second aspect of the invention, in order to correct the error of the flow potential value of the aggregated treated water to be measured, the standard solution is measured before or after the measurement of the flow potential value of the aggregated treated water. The flow potential is corrected by the flow potential value of the standard solution to correct the flow potential value of the actual agglutination treatment water, and the difference between the optimum value of the flow potential value of the agglutination treatment water and the correction value is used to calculate the inorganic aggregating agent. Insufficient concentration A. For example, in the method of controlling the agglutination agent injection according to item 3 of the patent application, wherein the following formula is corrected: E2=E1×(R2/R1) wherein E1: the flow potential value of the agglomerated treated water (measured value) [mV] E2: Flow potential value of agglutination treatment water (correction value) [mV] R1: Flow potential value of standard solution (when evaluation of bench test beforehand) [mV] R2: Flow potential value of standard solution (measurement of flow potential of agglutination treatment water) Before or after) [mV]. The method of controlling aggregating agent injection according to the first aspect of the invention, wherein a part of the agglomerated water is sampled in a measuring container to measure a flow potential, and the measured flow potential value is measured by titration to be negative to display 0. The addition amount B of the cationic polymer flocculating agent required for the value is c·B, and the additional addition amount of the inorganic aggregating agent is d·B, wherein c =0.1 to 0.9 d = 5 to 90. The method of controlling aggregating agent injection according to the first aspect of the invention, wherein the water to be treated is sampled in a measuring container, and the required flow potential value is measured by titration until a value of 0 is displayed. The amount C of the cationic polymer flocculating agent is set to e·C, and the amount of the inorganic aggregating agent added is f·C, where e=0.1 to 0.9 f=5～ 90. A flocculant injection control device which is a flocculant injection control device in a water treatment system in which a cationic polymer aggregating agent and an inorganic aggregating agent are added to a treated water and subjected to solid-liquid separation, and has the following features: a flow potentiometer for treating the flow potential of the water or the agglutination treatment water to which the aggregating agent is added; and calculating means for calculating the addition amount of the cationic polymer flocculant and the inorganic aggregating agent based on the measured value of the flow potentiometer . The aggregating agent injection control device according to claim 7, wherein the calculation means has a difference between an optimum value of a flow potential value of the agglutination treated water obtained by a prior test and a measured value of the control flow potential. A means for determining the insufficient concentration A of the inorganic aggregating agent; and a method of setting the amount of the inorganic aggregating agent to a·A and adding the cationic polymer aggregating agent to b·A. The aggregating agent injection control device according to the eighth aspect of the invention, wherein the calculating means includes: a measuring means for measuring a flow potential of the standard solution before or after the measurement of the flow potential value of the agglomerated water; a means for obtaining a correction value of the flow potential value of the aggregated treated water to be measured, and a difference between the optimum value of the flow potential value of the aggregated treated water and the correction value, and calculating the insufficient concentration A of the inorganic aggregating agent means. The aggregating agent injection control device according to claim 7, further comprising: a measurement container that houses a part of the agglutination water; a flow potentiometer provided in the measurement container; and the flow potentiometer is measured by titration The measured value is a means for reducing the amount of the cationic polymer flocculating agent required until the value of 0 is displayed; and calculating the additional amount of the cationic polymer flocculating agent to be c·B, and calculating the inorganic aggregating agent The additional addition amount is a means of d·B, wherein c=0.1 to 0.9 d=5 to 90. The aggregating agent injection control device according to claim 7, further comprising: a measurement container that accommodates a part of the water to be treated; the flow potentiometer provided in the measurement container; and the flow potentiometer is measured by titration The measured value is a means for reducing the amount C of the cationic polymer required until the value of 0 is displayed; and the amount of the cationic polymer flocculating agent is calculated as e·C, and the amount of the inorganic aggregating agent is calculated. The means of f·C, where e=0.1 to 0.9 f=5 to 90. The aggregator injection control device according to any one of claims 7 to 11, further comprising a light scattering type microparticle sensor for measuring turbidity in a void between the coagulation particles in the agglutination treatment water or Light intercepting microparticle sensor. A water treatment system having a water treatment system for aggregating agent injection control device according to any one of claims 7 to 12, characterized in that it has a solid solution for solid-liquid separation of agglomerated water. Liquid separation means. The water treatment system according to claim 13 which has a method of measuring an ORP value of the water to be treated, and means for adding an oxidizing agent to the water to be treated so that the ORP value of the water to be treated is 300 mV or more.