WO2016006419A1

WO2016006419A1 - Clumping method and clumping device

Info

Publication number: WO2016006419A1
Application number: PCT/JP2015/067772
Authority: WO
Inventors: 智之森田; 加藤　宏行; 鈴木　浩介
Original assignee: 水ｉｎｇ株式会社
Priority date: 2014-07-07
Filing date: 2015-06-19
Publication date: 2016-01-14
Also published as: JPWO2016006419A1

Abstract

The present invention pertains to a method for determining the appropriate injection ratio of a coagulant injected into a starting liquid containing a suspended matter. The clumping method includes: an injection step for injecting the coagulant into the starting liquid containing suspended matter; a stirring step for flowing the starting liquid into which the coagulant has been injected into a high-speed stirrer (1), rotating the stirring vane (8) of the high-speed stirrer (1) at a rotational velocity of at least 500 min^-1 to stir the starting liquid; an optical measurement step for obtaining an optical measurement value by radiating light at the stirred starting liquid; a numerical analysis step for obtaining a numerical analysis value by means of numerical analysis of the optical measurement value; and an injection ratio determination step for determining the appropriate injection ratio of the coagulant on the basis of the numerical analysis value.

Description

Aggregation method and apparatus

The present invention relates to a method for aggregating a stock solution containing a suspended substance, and more particularly to a method for determining an appropriate injection rate of a flocculant to be injected into a stock solution containing a suspended material. The present invention also relates to an aggregating apparatus using the aggregating method. In this specification, the stock solution refers to the liquid to be treated.

In order to reduce the volume of waste and reduce environmental impact, it is necessary to reduce the volume of undiluted liquids (such as wastewater and sludge) containing suspended solids discharged from wastewater treatment facilities and water purification facilities. Dehydration is extremely important. Therefore, development of more efficient and low running cost dehydration technology is desired.

The dehydration treatment of the stock solution containing suspended solids is composed of an aggregating step in which flocs are formed by aggregating the suspended solids using a flocculant and a dehydrating step in which the flocs are dehydrated by a dehydrator. Most of the running cost in this dehydration process is the cost of the flocculant.

In addition, agglomeration treatment (such as agglomeration sedimentation, agglomeration pressure flotation, agglomeration sand filtration, agglomeration membrane filtration) for purifying wastewater in a wastewater treatment facility, and agglomeration treatment (aggregation sedimentation, In the case of agglomerated sand filtration, agglomerated membrane filtration, etc.), most of the running cost is the cost of a flocculant. Therefore, it is desired to properly control the injection rate of the flocculant and reduce the amount of the flocculant used.

The following prior arts are known as techniques related to a method for appropriately controlling the injection rate of the flocculant.

In Patent Document 1, a sludge concentration meter that detects the concentration of sludge flowing through a sludge flow path, and sludge in a sludge storage tank is sent to a sludge dewatering machine according to the concentration of sludge detected by this sludge concentration meter. A concentration control device capable of controlling the concentration of sludge injected into the sludge dehydrator by operating at least one of the sludge injection pump and the coagulant injection pump that sends the coagulant in the coagulant storage tank to the sludge dewaterer; There is disclosed a wastewater treatment apparatus comprising:

Patent Document 2 discloses a measuring unit that measures the amount of floc present in a dehydrated separation liquid supplied to a measurement tank, and a flocculant that minimizes the amount of floc based on measurement data of the amount of floc by the measuring unit. There is disclosed a flocculant injection amount determination device including a control means for determining an injection amount.

Patent Document 3 discloses a flocculating means for injecting a flocculant into water or sludge in a reaction tank or in a flow path to flock suspended substances contained in the water or sludge in the reaction tank or in the flow path. And measuring means for measuring turbidity in the gap between flocs in the water or sludge using an agglomeration sensor provided in the reaction tank or in a flow path downstream of the agglomeration means, and this measurement And a control means for controlling the injection amount of the flocculant based on the change with time of the turbidity measured by the means. The aggregation sensor includes a probe that emits laser light into water or sludge and detects scattered light of the laser light generated by particles contained in the water or sludge.

Patent Document 4 discloses a sludge treatment apparatus in which a flocculant is added to a stock solution in a flocculent mixing tank to form a floc of suspended solids and the stock solution is supplied to a dehydrator. In this patent document 4, the size of the floc in the stock solution supply pipe for supplying the stock solution to the dehydrator is photographed, the luminance signal is converted into an electrical signal, and the magnitude of the floc is binarized from the electrical signal. Calculate the average area per floc from the binary image of floc, compare the average analysis area with the preset reference area of floc, calculate the appropriate value, and calculate the proportional set value based on the flock formation status A flocculant injection control method for controlling the flocculant injection rate is disclosed.

However, in a general flocculation step, the rotation speed of the stirring blade provided in the stirrer is 10 to 300 min ⁻¹ , and the flocculant is dispersed in the stock solution under relatively gentle conditions. In this case, a relatively good floc is formed with a wide range of flocculant injection rates. Therefore, even if the techniques disclosed in Patent Documents 1 to 4 are used, it is difficult to determine an appropriate injection rate of the flocculant with high accuracy.

JP 2004-167401 A Japanese Patent Laid-Open No. 11-347599 JP 2003-154206 A JP 2005-7338 A

The present invention has been made in view of the above-mentioned conventional problems, and efficiently aggregates the suspended substance in the stock solution containing the suspended substance, and automatically sets the appropriate injection rate of the flocculant with high accuracy. The object is to provide an aggregation method which can be determined. Moreover, an object of this invention is to provide the aggregating apparatus which can implement such an aggregating method.

One aspect of the present invention for solving the above-described problems includes an injection step of injecting a flocculant into a stock solution containing a suspended substance, and the stock solution into which the flocculant has been injected is allowed to flow into a high-speed stirrer. A stirring step of rotating the stirring blade at a rotation speed of 500 min ⁻¹ or more to stir the stock solution, an optical measurement step of obtaining an optical measurement value by irradiating the stirred stock solution with light, and the optical A numerical analysis step of numerically analyzing the measured value to obtain a numerical analysis value; and an injection rate determination step of determining an appropriate injection rate of the flocculant based on the numerical analysis value. Aggregation method.

In a preferred aspect of the present invention, the injection rate determining step determines whether the injection rate of the flocculant is appropriate based on the numerical analysis value, and the appropriate injection rate of the flocculant is determined. The injection step, the stirring step, the optical measurement step, and the numerical analysis step are repeated steps while changing the injection rate.
In a preferred aspect of the present invention, the change of the injection rate is to change one or both of a flow rate of the stock solution flowing into the high-speed stirrer and a flow rate of the flocculant injected into the stock solution. It is characterized by.
In a preferred aspect of the present invention, the optical measurement step is a step of measuring the transmitted light intensity by irradiating the stirred stock solution with light.
In a preferred aspect of the present invention, the optical measurement step is a step of measuring the scattered light intensity by irradiating the stirred stock solution with light.
In a preferred aspect of the present invention, the optical measurement step is a step of measuring both transmitted light intensity and scattered light intensity by irradiating the stirred stock solution with light.

In a preferred aspect of the present invention, the dispersion of the optical measurement value is used as the numerical analysis value.
In a preferred aspect of the present invention, a peak area of the optical measurement value is used as the numerical analysis value.
In a preferred aspect of the present invention, a standard deviation of the optical measurement value is used as the numerical analysis value.
In a preferred aspect of the present invention, the numerical analysis value is a floc particle size of the suspended substance.

In a preferred aspect of the present invention, the injection rate determination step includes a plurality of numerical values by repeating the injection step, the stirring step, the optical measurement step, and the numerical analysis step a plurality of times while changing the injection rate. It is a step of obtaining an analysis value and determining an appropriate injection rate of the flocculant based on the plurality of numerical analysis values.
In a preferred aspect of the present invention, an injection rate at which a maximum value or a minimum value is obtained among the plurality of numerical analysis values is determined as the appropriate injection rate.
A preferred aspect of the present invention is an average value of an injection rate at which a maximum value is obtained among the plurality of numerical analysis values and an injection rate at which a second largest value is obtained, or a minimum value among the plurality of numerical analysis values. An average value of an injection rate at which a value is obtained and an injection rate at which the second smallest value is obtained is determined as the appropriate injection rate.
A preferred aspect of the present invention is characterized by further comprising a correction injection rate determining step of determining a correction injection rate by multiplying the appropriate injection rate determined in the injection rate determination step by a correction coefficient.
A preferred embodiment of the present invention further includes a dilution step of diluting the stirred stock solution with a diluent, and the dilution step is performed between the stirring step and the optical measurement step.

In another aspect of the present invention, the flocculant injecting apparatus for injecting the flocculant into the stock solution containing the suspended substance, and the stock solution into which the flocculant is injected by rotating a stirring blade at a rotation speed of 500 min ⁻¹ or more. A high-speed stirrer that stirs, a supply device that supplies the stock solution to the high-speed stirrer, an optical measurement device that irradiates the stirred stock solution with light to obtain an optical measurement value, and the optical measurement value A flocculating apparatus comprising: a numerical analysis device that acquires a numerical analysis value by performing numerical analysis; and a control device that determines an appropriate injection rate of the flocculant based on the numerical analysis value. is there.

In a preferred aspect of the present invention, the control device determines whether or not an injection rate of the flocculant is appropriate based on the numerical analysis value, and until an appropriate injection rate of the flocculant is determined. , By operating any one or both of the flocculant injection device and the supply device, the high-speed stirrer, the optical measurement device, and the numerical analysis device to inject the flocculant into the stock solution, The agitation of the stock solution, the acquisition of the optical measurement value, and the acquisition of the numerical analysis value are repeated while changing the injection rate.
In a preferred aspect of the present invention, the optical measuring device measures the transmitted light intensity by irradiating the stirred stock solution with light.
In a preferred aspect of the present invention, the optical measuring device measures the scattered light intensity by irradiating the stirred stock solution with light.
In a preferred aspect of the present invention, the optical measuring device is both a measuring device for measuring transmitted light intensity and a measuring device for measuring scattered light intensity.

In a preferred aspect of the present invention, the numerical analysis device acquires a variance of the optical measurement value as the numerical analysis value.
In a preferred aspect of the present invention, the numerical analysis device acquires a peak area of the optical measurement value as the numerical analysis value.
In a preferred aspect of the present invention, the numerical analysis device acquires a standard deviation of the optical measurement value as the numerical analysis value.
In a preferred aspect of the present invention, the numerical analysis device acquires the particle size of floc of the suspended substance as the numerical analysis value.

In a preferred aspect of the present invention, the control device operates one or both of the flocculant injection device and the supply device, the high-speed stirrer, the optical measurement device, and the numerical analysis device. Injecting the flocculant into the stock solution, stirring the stock solution, obtaining the optical measurement value, and obtaining the numerical analysis value are repeated a plurality of times while changing the injection rate to obtain a plurality of numerical analysis values. Obtaining and determining an appropriate injection rate of the flocculant based on the plurality of numerical analysis values.
In a preferred aspect of the present invention, the control device determines an injection rate at which a maximum value or a minimum value is obtained among the plurality of numerical analysis values as the appropriate injection rate.
In a preferred aspect of the present invention, the control device is configured such that an average value of an injection rate at which a maximum value is obtained and an injection rate at which a second largest value is obtained among the plurality of numerical analysis values, or the plurality of numerical values. An average value of the injection rate at which the minimum value is obtained among the analysis values and the injection rate at which the second smallest value is obtained is determined as the appropriate injection rate.
In a preferred aspect of the present invention, the control device determines a correction injection rate by multiplying the determined appropriate injection rate by a correction coefficient.
In a preferred aspect of the present invention, the numerical analysis device is incorporated in the control device.
A preferred embodiment of the present invention is characterized by further comprising a diluent supply device for supplying a diluent to the stirred stock solution.

According to the present invention, the stock solution containing suspended solids infused with the flocculant is stirred at a high speed rotation with a rotation speed of the stirring blade being 500 min ⁻¹ or more. By this high-speed stirring, the flocculant is instantaneously dispersed in the stock solution, and the flocculant is efficiently and uniformly mixed with the stock solution. As a result, the suspended substance contained in the stock solution is efficiently aggregated. When this high-speed stirring is performed, a high stress is applied to the stock solution into which the flocculant is injected. Therefore, if the flocculant is not injected at an appropriate injection rate, the flocs are destroyed before growing. Therefore, if the flocculant to be injected is not at an appropriate injection rate, flocs will not grow properly. According to the present invention, the control device determines that the floc is growing properly from the numerical analysis value obtained by numerical analysis of the optical measurement value. Thereby, the appropriate injection rate of the flocculant can be determined with high accuracy. As a result, the amount of the flocculant used can be reduced. Moreover, the injection rate of the flocculant can be appropriately controlled without the experience and intuition of the operator. Furthermore, even if the properties of the stock solution containing the suspended material (for example, the concentration of the suspended material in the stock solution) change, the injection rate of the flocculant can be controlled appropriately.

It is the schematic of the optical measuring device which measures the transmitted light intensity. This is an example of measuring transmitted light intensity when no floc is formed because the injection rate of the flocculant is not appropriate. This is a measurement example of transmitted light intensity when flocs are formed because the injection rate of the flocculant is appropriate. It is the schematic of the optical measuring device which measures scattered light intensity. This is a measurement example of the scattered light intensity when no floc is formed because the injection rate of the flocculant is not appropriate. This is a measurement example of scattered light intensity when flocs are formed because the injection rate of the flocculant is appropriate. It is a flowchart of a series of processes for determining an appropriate injection rate. A flow showing the process for determining the appropriate injection rate of the flocculant by calculating the absolute value of the difference between the numerical analysis value and the predetermined target value and comparing the absolute value of this difference with the allowable value FIG. Multiple injection rates were set, multiple numerical analysis values were acquired for each of these injection rates, and the process for determining the appropriate injection rate of the flocculant by comparing the acquired multiple numerical analysis values was represented. FIG. It is the schematic which shows one Embodiment of the aggregation apparatus of this invention. It is the schematic which shows another embodiment of the aggregation apparatus of this invention. It is the schematic which shows another embodiment of the aggregation apparatus of this invention. It is the schematic which shows another embodiment of the aggregation apparatus of this invention. It is the schematic which shows another embodiment of the aggregation apparatus of this invention. It is the schematic which shows another embodiment of the aggregation apparatus of this invention. It is the schematic which shows another embodiment of the aggregation apparatus of this invention. It is the schematic which shows another embodiment of the aggregation apparatus of this invention. It is the schematic which shows another embodiment of the aggregation apparatus of this invention. It is the schematic which shows another embodiment of the aggregation apparatus of this invention. It is the schematic which shows another embodiment of the aggregation apparatus of this invention. It is the schematic which shows another embodiment of the aggregation apparatus of this invention. It is the schematic which shows another embodiment of the aggregation apparatus of this invention. It is the schematic which shows another embodiment of the aggregation apparatus of this invention. It is the schematic which shows another embodiment of the aggregation apparatus of this invention. It is the graph which plotted the result of the 3rd experiment.

Hereinafter, embodiments of the present invention will be described.
The flocculation method according to an embodiment of the present invention includes an injection step of injecting a flocculant into a stock solution containing a suspended substance, and the stock solution into which the flocculant has been injected flows into a high-speed stirrer, Stirring the stock solution by rotating at a rotational speed of 500 min ⁻¹ or more, an optical measurement step of irradiating the stirred stock solution with light to obtain an optical measurement value, and the optical measurement value A numerical analysis step of performing a numerical analysis to obtain a numerical analysis value; and an injection rate determination step of determining an appropriate injection rate of the flocculant based on the numerical analysis value.

In this specification, the undiluted solution refers to the liquid to be treated. Examples of the stock solution containing suspended solids include sludge discharged from a wastewater treatment facility or a water purification treatment facility, wastewater in a wastewater treatment facility, raw water in a water purification treatment facility, and the like. The sludge may be either organic sludge or inorganic sludge.

Examples of organic sludge include organic sludge generated in sewage treatment, human waste treatment, and wastewater treatment in various industries. More specifically, there may be mentioned first sedimentation basin sludge, surplus sludge, anaerobic digested sludge, aerobic digested sludge, human waste sludge, septic tank sludge, digestion desorbed liquid, coagulated sediment sludge, and the like. The organic sludge may contain an inorganic substance.

Examples of inorganic sludge include water purification treatment, wastewater treatment in construction work, and inorganic sludge generated in wastewater treatment in various industries. Here, the sludge generated in the water purification treatment is sludge discharged from a settling pond, a waste mud pond, a concentration tank, or the like in the water purification treatment facility. The inorganic sludge may contain organic matter.

Wastewater in wastewater treatment facilities includes wastewater from various industries such as sewage, food industry, drinking water industry, chemical industry, and machinery industry. Examples of raw water in water treatment facilities include river water, lake water, and groundwater.

Furthermore, the stock solution containing suspended solids may be water prepared in the course of treatment such as waste water treatment or water purification treatment. For example, as an example of the undiluted solution in the wastewater treatment, wastewater adjusted pH, wastewater injected with an inorganic flocculant, wastewater injected with an organic coagulant, wastewater injected with a metal chelating agent, and the like can be mentioned. For example, as an example of the stock solution in the water purification treatment, raw water with adjusted pH, raw water into which an inorganic flocculant has been injected, and the like can be given.

As the flocculant, any of inorganic flocculants, organic flocculants, and polymer flocculants can be used. Examples of the inorganic flocculant include ferric chloride, aluminum sulfate, aluminum chloride, polyaluminum chloride, iron sulfate, and polyiron sulfate.

Examples of organic coagulants include polyamine organic coagulants (such as polycondensates of dialkylamine and epichlorohydrin), diallyldimethylammonium chloride organic coagulants (such as polydiallyldimethylammonium chloride), and dicyandiamide organic coagulants (polydicyandiamide). Resin quaternary ammonium salt, etc.).

As the polymer flocculant, any of an anionic polymer flocculant, a nonionic polymer flocculant, a cationic polymer flocculant, and an amphoteric polymer flocculant can be used. When treating organic sludge, it is particularly preferable to use a cationic polymer flocculant or an amphoteric polymer flocculant.

Examples of the anionic polymer flocculant include sodium polyacrylate, a copolymer of sodium acrylate and acrylamide, polysodium methacrylate, a copolymer of sodium methacrylate and acrylamide, and the like.

Examples of nonionic polymer flocculants include polyacrylamide and polyethylene oxide.

Examples of cationic polymer flocculants include acrylate polymer flocculants (also referred to as “DAA polymer flocculants”), methacrylate polymer flocculants (also referred to as “DAM polymer flocculants”), and amide groups. , Nitrile groups, amine hydrochlorides, formamide groups, and the like, and polyvinylamidines (also referred to as “amidine polymer flocculants”), polyacrylamide Mannich modified products, and the like. Examples of the DAA polymer flocculant include a polymer of a quaternized product of dimethylaminoethyl acrylate, a copolymer of a quaternized product of dimethylaminoethyl acrylate and acrylamide, and the like. Examples of the DAM polymer flocculant include a polymer of a quaternized product of dimethylaminoethyl methacrylate and a copolymer of a quaternized product of dimethylaminoethyl methacrylate and acrylamide.

Examples of the amphoteric polymer flocculant include a quaternized product of dimethylaminoethyl acrylate and a copolymer of acrylamide and acrylic acid, a quaternized product of dimethylaminoethyl methacrylate, and a copolymer of acrylamide and acrylic acid. Can do.
However, the above is an example, and the present invention is not limited to these.

In the injection step, the aggregating agent as described above is injected into the stock solution containing suspended solids.

In the stirring step, the stock solution containing the suspended solids is stirred together with the flocculant by high-speed stirring in which the rotation speed of the stirring blade provided in the high-speed stirrer is set to 500 min ⁻¹ or more. By this high-speed stirring, the flocculant is instantaneously dispersed in the stock solution, and the flocculant is efficiently and uniformly mixed with the stock solution. When an inorganic flocculant or an organic flocculant is used as the flocculant, the main purpose of the stirring step is to form fine flocs by neutralizing the surface charge of the suspended substance. When the polymer flocculant is used as the flocculant, the surface charge of the suspended substance is neutralized, and the larger flocs are formed by the adsorption and crosslinking action of the polymer flocculant. Purpose.

In the conventional flocculation method, the flocculating agent is dispersed in the stock solution by stirring at a normal speed in which the rotation speed of the stirring blade of the stirrer is set to about 10 to 300 min ⁻¹ . For this reason, it is difficult to uniformly disperse the flocculant in the stock solution. On the other hand, in this embodiment, since the flocculant can be uniformly dispersed in the stock solution by high-speed stirring, the appropriate injection rate of the flocculant can be determined more accurately.

Further, in the conventional flocculation method, since the rotation speed of the stirring blade of the stirrer is set to about 10 to 300 min ⁻¹ , the flocculant is dispersed in the sludge under mild conditions. According to this conventional agglomeration method, the time required for floc formation is long and a large capacity agglomeration tank is required. In the conventional agglomeration method, a relatively good agglutination reaction occurs at a wide range of aggregating agent injection rates. On the other hand, in this embodiment, since the flocculant is dispersed in sludge under severe conditions by high-speed stirring, a good flocculation reaction occurs only when the injection rate is appropriate. Therefore, an appropriate injection rate can be determined with higher accuracy from the result of the aggregation reaction. In the present embodiment, the flocculant can be instantaneously dispersed in the stock solution, and flocs can be formed in a short time. Therefore, the appropriate injection rate of the flocculant can be determined more quickly.

As the stirrer, a high speed stirrer equipped with a stirring blade (stirring means) accommodated in a stirring tank, a rotating shaft to which the stirring blade is fixed, and a motor for rotating the rotating shaft can be used. Moreover, you may stir at high speed using a line mixer as a stirrer.

A line mixer is a mixer built into piping. The advantage of the line mixer is that the mixer is hermetically sealed, so if there are two pumps, one for the stock solution upstream of the line mixer and the other for the flocculant pump, the liquid can be sent downstream of the line mixer. is there. On the other hand, in the case of a stirrer in which a stirring blade is installed in the stirring tank, the upper part of the stirring tank is open, so in order to send the liquid downstream of the stirrer, the pump for the stock solution upstream of the stirrer and the coagulant In addition to the pump, another pump or a device equivalent to a pump is required. For this reason, usually, a pump is not installed and the liquid is generally sent downstream with a height difference.

In the stirring step, it is important to stir the stock solution containing the suspended solids into which the flocculant is injected by rotating the stirring blade at a rotation speed of 500 min ⁻¹ or more. Preferably, the rotation speed of the stirring blade is 1000 min ⁻¹ or more. More preferably, the rotation speed of the stirring blade is 2000 min ⁻¹ or more. More preferably, the rotation speed of the stirring blade is 3000 min ⁻¹ or more.

The rotation speed of the stirring blades depends on the type of stock solution containing suspended solids (for example, drainage and sludge), the nature of the stock solution (for example, SS (Suspended Solids concentration, viscosity, etc.)), and the type of flocculant (for example, inorganic Based on a coagulant, an organic coagulant, a polymer coagulant, etc.), it is adjusted at 500 min ⁻¹ or more. The floc formation in the stirring step may be performed in a stirring tank or in a pipe. The flocculant injected into the stock solution containing the suspended substance in the injection step may be injected into the stirring tank or may be injected into a pipe disposed upstream of the stirring tank.

The optical measurement step is performed to irradiate the stock solution containing floc formed in the stirring step with light to obtain an optical measurement value. Examples of the optical measurement values to be acquired include transmitted light intensity, transmittance, scattered light intensity, diffracted light intensity, diffracted / scattered light intensity, absorbance, and reflected light intensity. Multiple types of optical measurements may be measured simultaneously. For example, the transmitted light intensity may be measured and the scattered light intensity may be measured. In this case, both an optical measurement device that measures the transmitted light intensity and an optical measurement device that measures the scattered light intensity are provided.

In the optical measurement method, generally, an optical measurement device including a light source that emits light and a photodetector that receives light emitted from the light source is used. As a light source used in the optical measurement method, various lamps (mercury lamp, xenon lamp, krypton lamp, metal halide lamp, halogen lamp, etc.), various lasers (solid laser, semiconductor laser, liquid laser, gas laser, etc.), various An LED or the like can be used. As the photodetector, a CCD, photodiode, phototransistor, photomultiplier tube, photoconductive element, infrared sensor, CMOS, or the like can be used. In any case, a commercially available optical measuring device can be used as the optical measuring device.

FIG. 1 is a schematic view of an optical measuring apparatus for measuring transmitted light intensity. As shown in FIG. 1, a pair of

transparent windows

40, 40 through which light can pass is provided in a pipe 28 through which a stock solution containing floc flows. A light source 41 is disposed at a position where light can be emitted into the pipe 28 through one of the

transparent windows

40, 40, and a light detector 42 is disposed at a position where light emitted from the pipe 28 can be received through the other transparent window 40. Place. The light transmitted through the stock solution containing floc is detected by the photodetector 42. The transmitted light intensity is measured for a predetermined time, and the measured transmitted light intensity is used as an optical measurement value. The measurement of the transmitted light intensity is performed once or a plurality of times while changing the injection rate of the flocculant, thereby obtaining at least one optical measurement value. The transmitted light intensity detected by the photodetector 42 is accumulated in the data logger 50 and then sent to the numerical analysis device 5 described later. The numerical analysis value obtained by the numerical analysis device 5 is sent to the control device 6, and the control device 6 determines an appropriate injection rate of the flocculant based on the numerical analysis value. The data logger 50, the numerical analysis device 5, and the control device 6 may be provided separately. Alternatively, the data logger 50 and the numerical analysis device 5 may be incorporated in a control device 6 configured as one computer or one programmable logic controller (for example, a sequencer).

A measurement example in which the transmitted light intensity of a stock solution containing suspended solids (for example, sludge) is measured will be described with reference to FIGS. 2A and 2B. FIG. 2A shows an example of measurement of transmitted light intensity when flocs are not formed because the flocculant injection rate is not appropriate, and FIG. 2B shows flocs because the flocculant injection rate is appropriate. The measurement example of the transmitted light intensity in the case where is formed is shown. 2A and 2B, the horizontal axis represents measurement time, and the vertical axis represents transmitted light intensity.

As shown in FIG. 2A, if no floc is formed, the light emitted from the light source 41 is blocked by the suspended matter and hardly reaches the photodetector 42. As a result, the measured transmitted light intensity changes at a low value as the measurement time elapses. On the other hand, when the floc is formed, the suspended substance is collected as a floc. Therefore, as shown in FIG. 2B, there is a time when the light emitted from the light source 41 is blocked by the floc and does not reach the photodetector 42, and a time when the light reaches the photodetector 42 through the gap of the floc. As a result, a plurality of transmitted light intensity peaks are measured. The plurality of peaks are used in a numerical analysis process described later.

FIG. 3 is a schematic view of an optical measuring apparatus for measuring scattered light intensity. As shown in FIG. 3, an irradiator 43 </ b> A and a light receiver that receives scattered light generated by collision of light emitted from the irradiator 43 </ b> A with a suspended substance inside a pipe 28 through which a stock solution containing floc flows. 44A is spaced apart by a minute gap S. For example, the irradiator 43A and the light receiver 44A are arranged such that the central axis of the irradiator 43A and the central axis of the light receiver 44A intersect at an angle of 90 °. The irradiator 43A is an optical fiber that guides light from the light source 43B such as a laser to the inside of the pipe 28, and the light receiver 44A is an optical fiber that guides scattered light to a photodetector 44B such as a phototransistor. Light scattered by colliding with suspended matter or floc is detected by the photodetector 44B through the light receiver 44A. The photodetector 44B measures the scattered light intensity, and uses the measured scattered light intensity as an optical measurement value. The measurement of the scattered light intensity is performed once or a plurality of times while changing the injection rate of the flocculant, whereby at least one optical measurement value is obtained. The scattered light intensity detected by the photodetector 44B is accumulated in the data logger 50 and then sent to the numerical analysis device 5 described later. The numerical analysis value obtained by the numerical analysis device 5 is sent to the control device 6, and the control device 6 determines an appropriate injection rate of the flocculant based on the numerical analysis value. The data logger 50, the numerical analysis device 5, and the control device 6 may be provided separately. Alternatively, the data logger 50 and the numerical analysis device 5 may be incorporated in a control device 6 configured as one computer or one programmable logic controller (for example, a sequencer).

A measurement example in which the scattered light intensity of a stock solution containing suspended solids is measured will be described with reference to FIGS. 4A and 4B. FIG. 4A shows an example of measurement of scattered light intensity when no floc is formed because the injection rate of the flocculant is not appropriate. The upper graph shows the measured scattered light intensity, and the lower graph shows the scattered light intensity. Indicates the average intensity of light. FIG. 4B is a measurement example of the scattered light intensity when flocs are formed because the injection rate of the flocculant is appropriate. The upper graph shows the measured scattered light intensity, and the lower graph shows the scattered light. Indicates the average intensity of light. 4A and 4B, the horizontal axis represents the measurement time, and the vertical axis represents the scattered light intensity or the average intensity of the scattered light. Here, the average intensity is an average intensity for a predetermined time.

If the floc is not formed, a lot of suspended matter enters the minute gap S, and more light is reflected from the suspended matter. Therefore, the intensity of the scattered light measured by the photodetector 44B becomes high as shown in FIG. 4A. On the other hand, when the floc is formed, the suspended substance is collected as a floc. In this case, the amount of the suspended substance entering the minute gap S is reduced, and the light reflected from the suspended substance is reduced. Therefore, the intensity of the scattered light measured by the photodetector 44B becomes low as shown in FIG. 4B. This scattered light intensity is used in a numerical analysis process described later. The average intensity of the scattered light may be used in the numerical analysis process.

Note that, when the scattered light intensity is used as an optical measurement value, for example, the formation of flocs is determined by the decrease in the intensity of scattered light (or the average intensity of the scattered light) from the suspended substance. Therefore, the measurement of scattered light intensity is not suitable for a stock solution having a high concentration of suspended solids such as sludge and a relatively large suspended solid and a large floc formed. On the other hand, the scattered light intensity measurement is a stock solution containing a fine suspended substance, and the formed floc is also suitable for the measurement of a fine stock solution. Such a stock solution is, for example, raw water for water purification treatment.

In the numerical analysis process, numerical analysis values are obtained by numerical analysis of the optical measurement values obtained in the optical measurement process. Examples of numerical analysis values include an average value of optical measurement values, dispersion, standard deviation, peak area, peak height, and the like. The dispersion of the optical measurement values is a value obtained by statistically analyzing the optical measurement values, and is an amount indicating the degree of dispersion of the distribution of the optical measurement values obtained during a predetermined measurement time. Standard deviation is the positive value of the square root of the variance. The peak area is a graph drawn by plotting optical measurement values obtained during a predetermined measurement time on a graph in which the vertical axis represents the optical measurement value and the horizontal axis represents the measurement time, and the reference This is the area of a region surrounded by a line (for example, a base line). The peak area corresponds to the area of the hatched area in FIG. 2B, for example. The peak height is the peak of a curve drawn by plotting the optical measurement values obtained during a given measurement time on a graph where the vertical axis represents the optical measurement value and the horizontal axis represents the measurement time. The height from the horizontal axis.

The number of optical measurement values above a certain threshold or the number of optical measurement values below a certain threshold may be used as a numerical analysis value. In the numerical analysis step, SS concentration, turbidity, chromaticity, floc particle size, etc. may be calculated from the optical measurement values, and these may be used as numerical analysis values. Here, the floc particle diameter means the diameter of the floc when the floc is spherical. When the floc is not spherical, the floc particle diameter means a Stokes diameter or a particle diameter measured by various measuring methods. The floc particle size may be the average particle size of the floc. Examples of the average particle diameter include an arithmetic average diameter, a maximum diameter, and a median diameter. The average particle diameter may be based on the number, may be based on mass, or may be based on volume.

As a method for calculating the SS concentration and turbidity from the optical measurement values, known methods such as a transmitted light measurement method, a scattered light measurement method, a transmitted light / scattered light comparison method, an integrating sphere measurement method, and the like can be used. As a method for calculating chromaticity from the optical measurement value, a known method such as a transmitted light measurement method can be used. As a method for calculating the floc particle diameter from the optical measurement value, a known method such as a laser diffraction / scattering method or a method of analyzing an image taken with a camera can be used. The floc particle size may be an average floc particle size or a particle size distribution of floc particle size. A commercially available measuring apparatus capable of calculating the SS concentration, turbidity, chromaticity, floc particle diameter and the like from the obtained optical measurement values can be used while performing optical measurement.

The injection rate determining step determines the appropriate injection rate of the flocculant from at least one numerical analysis value obtained by performing the flocculant injection step, the stirring step, the optical measurement step, and the numerical analysis step at least once. It is a step of determining. That is, in the present embodiment described so far, a flocculant is injected into a stock solution containing a suspended substance, the stock solution is stirred at a high speed in order to form a floc of the suspended material, and the stirred stock solution is optically mixed. The measurement is performed, and the obtained optical measurement value is numerically analyzed to obtain a numerical analysis value. Based on the obtained numerical analysis value, it is determined whether or not the injection rate of the flocculant is appropriate, and if the injection rate is not appropriate, the injection rate of the flocculant is changed, and the stirring step, the optical measurement step, Repeat the numerical analysis process to determine the proper injection rate. Depending on the injection rate of the flocculant, the suspended substance flocs may not be formed.

The injection rate of the flocculant injected into the stock solution containing suspended solids can be changed by changing the flow rate of the flocculant injected into the stock solution while the flow rate of the stock solution is controlled to be constant. Alternatively, the injection rate of the flocculant may be changed by changing the flow rate of the stock solution while the flow rate of the flocculant is controlled to be constant. Alternatively, both the flow rate of the stock solution and the flow rate of the flocculant may be changed in order to change the injection rate of the flocculant.

FIG. 5 shows a flow chart showing a process for determining an appropriate injection rate. As shown in FIG. 5, in this embodiment, first, the injection rate a of the flocculant is set (step 1). The flocculant is injected into the stock solution containing the suspended substance at this injection rate a, and the stock solution is stirred at high speed together with the flocculant to form a floc (step 2). Optical measurements are performed on the stirred stock solution (step 3). Numerical analysis is performed on the optical measurement value obtained by the optical measurement, and thereby the numerical analysis value X is obtained (step 4). Based on this numerical analysis value X, it is determined whether or not the injection rate of the flocculant is appropriate (step 5).

If the injection rate of the flocculant is not appropriate, the injection rate a of the flocculant is changed (step 6). In step 6, when the appropriate injection rate is determined by gradually decreasing the injection rate from the high injection rate, the predetermined change width b is subtracted from the injection rate a. When the appropriate injection rate is determined by gradually increasing the injection rate from the low injection rate a, a predetermined change width b is added to the injection rate a. At this changed injection rate a, Step 2, Step 3, Step 4, and Step 5 are repeated to obtain a new numerical analysis value X, and the flocculant injection is performed based on the new numerical analysis value X. It is determined whether the rate is appropriate. When the injection rate of the flocculant is appropriate, the determining step of the injection rate of the flocculant is completed.

As a method of determining whether or not the injection rate of the flocculant is appropriate in Step 5, an absolute value of a difference between the numerical analysis value and a predetermined target value is obtained, and the absolute value of this difference is determined in advance. When the value is smaller than the value, there is a method of determining that the injection rate of the flocculant is appropriate. If the absolute value of the difference between the numerical analysis value and the target value is equal to or greater than the allowable value, the flocculant injection rate is changed and the flocculant injection process, stirring process, optical measurement process, and numerical analysis process are performed. Try again. Then, until the absolute value of the difference between the numerical analysis value and the target value obtained is smaller than the allowable value, the flocculant injection process, stirring process, optical measurement process, numerical analysis process, Change and repeat.

An absolute value of the difference between the numerical analysis value described above and a predetermined target value is obtained, and a process for determining an appropriate injection rate of the flocculant by comparing the absolute value of this difference with an allowable value is shown. A flow chart is shown in FIG. As shown in FIG. 6, an injection rate a is set (step 1), and at this injection rate a, the flocculant is injected into the stock solution containing suspended solids, and the stock solution is fasted together with the flocculant to form a floc. Stir (step 2). Optical measurements are performed on the stirred stock solution (step 3). Numerical analysis is performed on the optical measurement value obtained by the optical measurement, and a numerical analysis value X is obtained (step 4). Based on the numerical analysis value X obtained by numerical analysis, it is determined whether or not the injection rate of the flocculant is appropriate (step 5). In step 5, the absolute value of the difference between the predetermined target value Xt and the numerical analysis value X is calculated, and the absolute value of this difference is compared with a preset allowable value m.

When the absolute value of the difference between the predetermined target value Xt and the numerical analysis value X is greater than or equal to the allowable value m, it is determined that the flocculant injection rate is not appropriate, and the flocculant injection rate a is changed. (Step 6). In step 6, when the appropriate injection rate is determined by gradually decreasing the injection rate from the high injection rate, the predetermined change width b is subtracted from the injection rate a. When the appropriate injection rate is determined by gradually increasing the injection rate from the low injection rate a, a predetermined change width b is added to the injection rate a. Step 2, Step 3, Step 4 and Step 5 are repeated with this changed injection rate a to obtain a new numerical analysis value X. Based on this new numerical analysis value X, the injection rate of the flocculant It is determined again whether or not is appropriate. When the absolute value of the difference between the predetermined target value Xt and the numerical analysis value X is smaller than the allowable value m, that is, when the injection rate of the flocculant is appropriate, the determination process of the flocculant injection rate ends. .

Other methods for determining an appropriate flocculant injection rate include the methods described below. In this method, a plurality of injection rates are set in advance. At each of a plurality of preset injection rates, the flocculant is injected into the stock solution containing suspended solids, and the stock solution is stirred at a high speed together with the flocculant to form a floc. Then, the stock solution stirred at each of the plurality of injection rates is subjected to optical measurement, and a plurality of numerical analysis values at each of the plurality of injection rates are acquired. The obtained numerical analysis values are compared, and, for example, the injection rate at which the maximum value or the minimum value is obtained is determined as an appropriate injection rate. A flowchart of this series of steps is shown in FIG. FIG. 7 is for setting a plurality of injection rates, acquiring a plurality of numerical analysis values for each of these injection rates, and determining the appropriate injection rate of the flocculant by comparing the acquired plurality of numerical analysis values. It is a flowchart showing a process.

As shown in FIG. 7, in this method, a plurality (n) of injection rates ai = a1, a2,... An are set (step 1). i is set to 1 and the first injection rate ai (= a1) is selected (step 2). The flocculant is injected into the stock solution containing the suspended substance at the injection rate a1, and the stock solution is stirred at a high speed together with the flocculant to form a floc (step 3). An optical measurement is performed on the stirred stock solution (step 4). Numerical analysis is performed on the optical measurement value obtained by the optical measurement, thereby obtaining a numerical analysis value Xi (= X1) (step 5). Thereafter, it is determined whether i = n (step 6). If i is not n, 1 is added to i (step 7). For example, when i is 1, i is changed to 2, and a2 is selected as the injection rate ai.

The numerical analysis value Xi is acquired by repeating Step 3, Step 4 and Step 5 again with the changed injection rate ai. For example, when ai = a2, a numerical analysis value X2 is obtained, and when ai = a3, a numerical analysis value X3 is obtained. In order to obtain the numerical analysis value Xi, Step 3, Step 4, and Step 5 are repeated until i = n. Therefore, numerical analysis values X1, X2,... Xn are obtained. Based on the obtained numerical analysis values X1, X2,... Xn, an appropriate injection rate of the flocculant is determined (step 8). For example, the injection rate at which the maximum value or the minimum value of the numerical analysis values X1, X2,... Xn is obtained is determined as an appropriate injection rate.

The average value of the injection rate at which the largest numerical analysis value was obtained and the injection rate at which the second largest numerical analysis value was obtained may be used as the appropriate injection rate. Or it is good also considering the average value of the injection rate from which the smallest numerical analysis value was obtained, and the injection rate from which the 2nd smallest numerical analysis value was obtained as an appropriate injection rate.

Further, the following method may be employed as yet another method for determining the appropriate coagulant injection rate based on the obtained numerical analysis values X1, X2,... Xn. The numerical analysis values X1, X2,... Xn at the injection rates a1, a2,... An are plotted on the graph in which the vertical axis represents the numerical analysis values and the horizontal axis represents the injection rate of the flocculant. An approximate expression indicating the relationship between the injection rates a1, a2,... An and the numerical analysis values X1, X2,... Xn is calculated, and based on the obtained approximate expression, an appropriate injection rate of the flocculant Can be determined. For example, the injection rate at which the peak value of the numerical analysis value is obtained can be calculated from the approximate expression, and the obtained injection rate can be set as an appropriate injection rate of the flocculant.

Furthermore, the agglomeration method described above may include a diluting step of diluting the stock solution stirred at high speed in the stirring step with a diluting solution, if necessary. The dilution step is performed between the stirring step and the optical measurement step. For example, in the flowchart shown in FIG. 5, it is implemented between Step 2 and Step 3, and in the flowchart shown in FIG. 6, it is implemented between Step 2 and Step 3. In the flowchart shown in FIG. 7, the process is performed between Step 3 and Step 4.

The purpose of the dilution process is to reduce the concentration of suspended matter or floc by diluting the stirred stock solution with the diluent. In stock solutions with a high concentration of suspended solids, there is no difference between the optical measurement when floc is formed and the optical measurement when no floc is formed, and as a result, it is difficult to determine the injection rate of the flocculant. There are cases. For example, in the optical measurement process, when measuring the transmitted light intensity of a stock solution with a high concentration of suspended solids, there is almost no gap between the flocs even if flocs are formed with an appropriate injection rate of the flocculant, As shown in FIG. 2A, the transmitted light intensity may become substantially constant. On the other hand, when diluting the stirred stock solution with the diluent, the gap between the flocks can be increased, so that light is transmitted through the gap between the flocks, and as shown in FIG. Multiple peaks are measured. As a result, there is a difference between the transmitted light intensity when the floc is formed and the transmitted light intensity when the floc is not formed, and an appropriate injection rate can be determined. As the diluent, pure water, tap water, industrial water, ground water, treated water for various wastewater treatment, seawater, and the like can be used.

The corrected injection rate may be determined by multiplying the obtained appropriate injection rate by a correction coefficient. When the corrected injection rate is determined, this corrected injection rate is used as the injection rate of the flocculant injected into the stock solution containing suspended solids. The step of determining the corrected injection rate is performed after an appropriate injection rate is determined in the injection rate determination step. For example, when it is desired to suppress the running cost of the flocculant, an appropriate injection rate obtained in the injection rate determination step may be multiplied by a correction coefficient of 0.9. When it is desired to increase the dewatering efficiency in the dewatering step performed after the aggregation step, the appropriate injection rate obtained in the injection rate determining step may be multiplied by a correction coefficient of 1.1.

As described so far, in the above-described embodiment, the stock solution containing suspended solids, into which the flocculant is injected, is stirred at a high speed rotation in which the rotation speed of the stirring blade is 500 min ⁻¹ or more. By this high-speed stirring, the flocculant is instantaneously dispersed in the stock solution, and the flocculant is efficiently and uniformly mixed with the stock solution. As a result, the suspended substance contained in the stock solution is efficiently aggregated. When this high-speed stirring is performed, a high stress is applied to the stock solution into which the flocculant is injected. Therefore, if the flocculant is not injected at an appropriate injection rate, the flocs are destroyed before growing. Therefore, if the flocculant to be injected is not at an appropriate injection rate, flocs will not grow properly. According to the above-described embodiment, the control device to be described later determines that the floc is growing properly from the numerical analysis value obtained by numerical analysis of the optical measurement value. Thereby, the appropriate injection rate of the flocculant can be determined with high accuracy. As a result, the amount of the flocculant used can be reduced. Moreover, the injection rate of the flocculant can be appropriately controlled without the experience and intuition of the operator. Furthermore, even if the properties of the stock solution containing the suspended material (for example, the concentration of the suspended material in the stock solution) change, the injection rate of the flocculant can be controlled appropriately.

Further, in the conventional flocculation method, the flocculant is dispersed in the stock solution by stirring at a normal speed in which the rotation speed of the stirrer of the stirrer is set to about 10 to 300 min ^−1. Is difficult. On the other hand, in the above-described embodiment, the flocculant can be uniformly dispersed in the stock solution by high-speed stirring in which the rotation speed of the stirring blade is 500 min ⁻¹ or more. Can be determined. Furthermore, in the above-described embodiment, since the flocculant can be instantaneously dispersed in the stock solution and flocs can be formed in a short time, the appropriate injection rate of the flocculant can be determined more quickly.

Next, an aggregating apparatus for carrying out the above-described aggregating method will be described.
FIG. 8 is a schematic view showing an embodiment of the aggregating apparatus of the present invention. The aggregating apparatus shown in FIG. 8 has a configuration in which a stock solution storage tank 10, a high-speed stirrer 1, and an optical measuring device 3 are connected in series in this order. The stock solution storage tank 10 stores a stock solution containing suspended solids. The high-speed stirrer 1 includes a high-speed stirring tank 2 to which a stock solution containing suspended solids is supplied, a high-speed stirring blade 8 that stirs the stock solution containing suspended solids, and a high-speed motor 9 as a drive device that rotates the high-speed stirring blade 8. With. A supply source pipe 18 extending from the stock solution storage tank 10 is connected to the high speed stirring tank 2 of the high speed stirrer 1, and the stock solution stored in the stock solution storage tank 10 is supplied to the high speed stirring tank 2 at a predetermined flow rate. A supply device 7 is arranged. The supply device 7 is, for example, a pump, a valve, or a combination of a pump and a valve.

A discharge pipe 28 through which the stock solution discharged from the high-speed stirring tank 2 flows is connected to the high-speed stirring tank 2, and the optical measuring device 3 is disposed in the discharge pipe 28. The optical measuring device 3 is, for example, a measuring device that measures the above-described transmitted light intensity or a measuring device that measures scattered light intensity. An optical measurement device that measures transmitted light intensity and an optical measurement device that measures scattered light intensity may be arranged in series. The optical measuring device 3 may be a measuring device capable of measuring transmittance, intensity of diffracted light, intensity of diffracted / scattered light, absorbance, intensity of reflected light, and the like.

A flocculant storage tank 11 for storing the flocculant is provided, and a flocculant supply pipe 26 extending from the flocculant storage tank 11 is connected to the high-speed stirring tank 2. The flocculant supply pipe 26 is provided with the flocculant injection device 4. The flocculant injection device 4 is a device that injects the flocculant at a predetermined injection rate into the stock solution containing suspended solids. The flocculant injection device 4 is, for example, a pump, a valve, or a combination of a pump and a valve.

In this aggregating apparatus, the stock solution containing suspended solids is supplied from the stock solution storage tank 10 to the high-speed stirring tank 2 by the supply device 7. The flocculant is supplied to the high-speed stirring tank 2 by the flocculant injection device 4. In the high-speed agitation tank 2, the stock solution and the flocculant are mixed at a high-speed rotation in which the rotation speed of the high-speed agitation blade 8 is 500 min ⁻¹ or more, thereby forming suspended matter flocs. Depending on the injection rate of the flocculant, the suspended substance flocs may not be formed. That is, in the high-speed stirrer 1, the high-speed stirring blade 8 is rotated at a high speed to form a suspended substance floc, but depending on the injection rate of the flocculant, the suspended substance floc may not be formed.

A numerical analysis device 5 is electrically connected to the optical measurement device 3, and a control device 6 is electrically connected to the numerical analysis device 5. The numerical analysis device 5 may be incorporated in the control device 6. The control device 6 is electrically connected to the flocculant injection device 4.

In such a configuration, the optical measurement value obtained from the optical measurement device 3 is sent to the numerical analysis device 5 as described above. The numerical analysis device 5 numerically analyzes the optical measurement value and acquires the numerical analysis value. The obtained numerical analysis value is sent to the control device 6. The control device 6 determines an appropriate injection rate of the flocculant based on the numerical analysis value by the method as described above.

FIG. 9 is a schematic view showing another embodiment of the aggregating apparatus of the present invention. In the coagulation apparatus shown in FIG. 9, the coagulant supply pipe 26 that supplies the coagulant is connected to the supply source pipe 18 and is not connected to the high-speed stirring tank 2. Since the other configuration is the same as that of the embodiment shown in FIG. 8, the corresponding components are denoted by the same reference numerals, and detailed description thereof is omitted. In this embodiment, the flocculant is injected into the supply source pipe 18 disposed on the upstream side of the high-speed stirring tank 2. Thus, the flocculant injected into the stock solution containing the suspended solids may be injected into the high-speed stirring tank 2 as shown in FIG. 8, or more than the high-speed stirring tank 2 as shown in FIG. You may inject | pour into the supply pipe | tube 18 arrange | positioned upstream.

FIG. 10 is a schematic view showing still another embodiment of the aggregating apparatus of the present invention. In the aggregating apparatus shown in FIG. 10, a line mixer is employed as the high-speed stirrer 1. Since the other configuration is the same as that of the embodiment shown in FIG. 9, the corresponding components are denoted by the same reference numerals, and detailed description thereof is omitted. The line mixer 1 is a mixer incorporated in a pipe. The advantage of the line mixer 1 is that the line mixer 1 is hermetically sealed. Therefore, if there are two pumps, that is, a supply device 7 disposed upstream of the line mixer 1 and a flocculant injection device 4, the line mixer 1 It is a point which can send undiluted | stock solution downstream.

FIG. 11 is a schematic view showing still another embodiment of the aggregating apparatus of the present invention. In the aggregating apparatus shown in FIG. 11, an aggregating tank agitator 12 different from the high-speed agitator 1 described so far is provided. The agglomeration tank agitator 12 is a conventionally used agitator, and the rotation speed of the agitation blade of the agglomeration tank agitator 12 is set to a normal speed of about 10 to 300 min ⁻¹ . The supply source pipe 18 extending from the stock solution storage tank 10 branches into a first supply pipe 19 connected to the high-speed stirrer 1 and a second supply pipe 25 connected to the coagulation tank stirrer 12. The high-speed stirrer 1, the supply device 7, the optical measurement device 3, the flocculant injection device 4, and the flocculant supply pipe 26 are the same as those in the embodiment shown in FIG. Thus, detailed description thereof is omitted. Hereinafter, the supply device 7 is referred to as a first supply device 7, the flocculant injection device 4 is referred to as a first flocculant injection device, and the flocculant supply pipe 26 is referred to as a first flocculant supply pipe.

The agglomeration tank agitator 12 is a coagulation agitation tank 37 to which a stock solution containing a suspended substance is supplied, a coagulation tank agitation blade 38 for agitating the stock solution containing a suspended substance, and a drive device that rotates the agglomeration tank agitation blade 38. A coagulation tank motor 39 is provided. A second supply pipe 25 is connected to the coagulation agitation tank 37 of the coagulation tank agitator 12, and the second supply pipe 25 supplies a stock solution containing suspended solids to the aggregation agitation tank 37 at a predetermined flow rate. Two supply devices 35 are arranged. The second supply device 35 is, for example, a pump, a valve, or a combination of a pump and a valve.

In the embodiment shown in FIG. 11, the first supply pipe 19 branches from between the stock solution storage tank 10 and the second supply apparatus 35, but the second supply apparatus 35 and the agglomeration stirring tank 37. You may branch from between. Alternatively, the first supply pipe 19 may be directly connected to the stock solution storage tank 10. In this case, the supply source pipe 18 is omitted.

A second flocculant supply pipe 36 extending from the flocculant storage tank 11 for storing the flocculant is connected to the flocculant stirring tank 37. A second flocculant injection device 45 is disposed in the second flocculant supply pipe 36. The second flocculant injection device 45 is a device that injects the flocculant into the stock solution containing the suspended substance at a predetermined injection rate. The flocculant injection device 45 is, for example, a pump, a valve, or a combination of a pump and a valve. The flocculant storage tank 11 is also connected to the high-speed stirring tank 2 via the first flocculant supply pipe 26. In the embodiment shown in FIG. 11, the first flocculant supply pipe 26 is directly connected to the flocculant storage tank 11, but from between the flocculant storage tank 11 and the second flocculant injection device 45. It may branch off. Alternatively, the first flocculant supply pipe 26 may be branched from between the second flocculant injection device 45 and the flocculant stirring tank 37.

A second discharge pipe 46 through which the stock solution discharged from the coagulation stirring tank 37 flows is connected to the coagulation stirring tank 37, and the dehydrator 14 is connected to the downstream side of the second discharge pipe 46. The dehydrator 14 dehydrates the stock solution in which flocks are formed, and separates it into a filtrate and a cake. The cake is recovered from the dehydrator 14.

A numerical analysis device 5 is electrically connected to the optical measurement device 3 arranged on the downstream side of the high-speed stirrer 1, and a control device 6 is electrically connected to the numerical analysis device 5. The numerical analysis device 5 may be incorporated in the control device 6. The control device 6 is electrically connected to the first flocculant injection device 4 and the second flocculant injection device 45.

In the aggregating device having such a configuration, first, the first supply device 7 is operated to supply a stock solution containing suspended solids to the high-speed stirrer 1. The stock solution stirred at high speed by the high-speed stirrer 1 is sent to the optical measuring device 3. The optical measuring device 3 performs an optical measurement of the stock solution stirred at a high speed to obtain an optical measurement value. The optical measurement value obtained from the optical measurement device 3 is sent to the numerical analysis device 5 as described above. The numerical analysis device 5 numerically analyzes the optical measurement value and acquires the numerical analysis value. The obtained numerical analysis value is sent to the control device 6. The control device 6 determines an appropriate injection rate of the flocculant based on the numerical analysis value by the method as described above.

The determined injection rate is sent to the second flocculant injection device 45. Then, the first supply device 7 is stopped and the second supply device 35 is operated. Thereby, the stock solution stored in the stock solution storage tank 10 is supplied to the agglomeration tank agitator 12. The injection rate of the flocculant injected into the coagulation tank agitator 12 is the injection rate determined previously. In this way, the flocculant is injected into the stock solution at an appropriate injection rate, and flocs are formed in the stock solution. The stock solution containing the flock is sent to the dehydrator 14 and dehydrated by the dehydrator 14.

FIG. 12 is a schematic view showing still another embodiment of the aggregating apparatus of the present invention. In the aggregating apparatus shown in FIG. 12, a settling tank 20 is provided instead of the dehydrator 14. Since the other configuration is the same as that of the embodiment shown in FIG. 11, the corresponding components are denoted by the same reference numerals, and detailed description thereof is omitted. The floc in the undiluted solution supplied to the settling tank 20 settles toward the bottom of the settling tank 20 due to its own weight, so that the undiluted solution containing the floc is a concentrated undiluted solution in which the floc exists at a high concentration (for example, concentrated sludge) And the processed liquid without floc. By providing the precipitation tank 20 in this way, it is possible to separate the floc and the processed liquid.

FIG. 13 is a schematic view showing still another embodiment of the aggregating apparatus of the present invention. In the coagulation apparatus shown in FIG. 13, a coagulation tank agitator 21 different from the coagulation tank agitator 12 is connected to the coagulation tank agitator 12 in series with the coagulation tank agitator 12. Hereinafter, the agglomeration tank agitator 12 is referred to as a first agglomeration tank agitator 12, and the agglomeration tank agitator 21 is referred to as a second agglomeration tank agitator 21. The second agglomeration tank stirrer 21 is a conventionally used agitator, and the rotation speed of the stirring blades of the agglomeration tank agitator 21 is set to a normal speed of about 10 to 300 min ⁻¹ . Other configurations that are not particularly described are the same as those of the embodiment shown in FIG. 12, and therefore, corresponding components are denoted by the same reference numerals, and detailed description thereof is omitted.

The second agglomeration tank agitator 21 of the embodiment shown in FIG. 13 includes a second agglomeration agitation tank 47 to which the stock solution in which flocks are formed by the first agglomeration tank agitator 12 is supplied, and a second agitation tank agitation 2 agglomeration tank agitation blades 48 and a second agglomeration tank motor 49 as a driving device for rotating the second agglomeration tank agitation blades 48. The second aggregation stirring tank 47 is adjacent to the first aggregation stirring tank 37, and the second aggregation stirring tank 47 is directly connected to the first aggregation stirring tank 37. A second flocculant different from the first flocculant supplied to the high-speed agitation tank 2 and the first agglomeration agitation tank 37 is supplied to the second agglomeration agitation tank 47. The second flocculant is stored in the second flocculant storage tank 23. A third flocculant supply pipe 52 for supplying the second flocculant from the second flocculant reservoir 23 to the second flocculent agitation tank 47 is provided from the second flocculant reservoir 23 to the second flocculant agitation tank. 47. The third flocculant supply pipe 52 is provided with a third flocculant injection device 53, and the second flocculant is injected into the second flocculant stirring tank at a predetermined injection rate by the third flocculant injection device 53. 47 is injected. The third flocculant injection device 53 is, for example, a pump, a valve, or a combination of a pump and a valve.

For example, an inorganic flocculant is used as the first flocculant. For example, a polymer flocculant is used as the second flocculant. When an inorganic flocculant is used, the surface charge of the suspended material is neutralized, thereby forming fine flocs. When the polymer flocculant is used, the surface charge of the suspended substance is neutralized, and a larger floc is formed by the adsorption action and the crosslinking action of the polymer flocculant. Therefore, by using these two different flocculants, a strong floc with good filterability can be formed.

FIG. 14 is a schematic view showing still another embodiment of the aggregating apparatus of the present invention. Other configurations that are not particularly described are the same as those of the embodiment shown in FIG. 13, and therefore, the corresponding components are denoted by the same reference numerals, and detailed description thereof is omitted. In the coagulation apparatus shown in FIG. 14, a second coagulation tank agitator 21 is connected in series with the first coagulation tank agitator 12. The first flocculating tank stirrer 12 and the second flocculating tank stirrer 21 are connected by a connection pipe 55, and a third supply pipe 57 extending to the high speed stirrer 1 is branched from the connection pipe 55. The second flocculant is supplied from the second flocculant storage tank 23 to the high-speed stirrer 1. Therefore, the stock solution measured by the optical measuring device 3 is a stock solution in which the first flocculant and the second flocculant are injected and stirred at a high speed. The appropriate injection rate of the second flocculant is determined by the control device 6.

The first flocculating tank stirrer 12 and the second flocculating tank stirrer 21 are connected by a connection pipe 55. A third supply pipe 57 extending to the high speed stirrer 1 is branched from the connection pipe 55. A third supply device 56 is arranged on the downstream side of the connection pipe 55 where the third supply pipe 57 is branched. The third supply device 56 is, for example, a pump, a valve, or a combination of a pump and a valve. In the embodiment shown in FIG. 14, the third supply pipe 57 is branched from between the first agglomeration stirring tank 37 and the third supply device 56, but the third supply device 56 You may branch from between the 2nd aggregation stirring tank 47. Alternatively, the third supply pipe 57 may be directly connected to the first aggregation stirring tank 37.

A fourth flocculant supply pipe 58 extends from the second flocculant storage tank 23 in which the second flocculant is stored, and the fourth flocculant supply pipe 58 is connected to the high-speed stirrer 1. . The fourth flocculant supply pipe 58 is provided with the first flocculant injection device 4. Further, a third flocculant supply pipe 52 for supplying the second flocculant from the second flocculant storage tank 23 to the second flocculant stirring tank 47 is provided from the second flocculant storage tank 23 to the second flocculant. It extends to the stirring tank 47. The third flocculant supply pipe 52 is provided with a third flocculant injection device 53, and the second flocculant is injected into the second flocculant stirring tank at a predetermined injection rate by the third flocculant injection device 53. 47 is injected. In the embodiment shown in FIG. 14, the fourth flocculant supply pipe 58 is directly connected to the second flocculant reservoir 23, but the second flocculant reservoir 23 and the third flocculant injection You may branch from between the apparatuses 53. FIG. Alternatively, the fourth flocculant supply pipe 58 may be branched from between the third flocculant injection device 53 and the second flocculent stirring tank 47.

A numerical analysis device 5 is electrically connected to the optical measurement device 3 arranged on the downstream side of the high-speed stirrer 1, and a control device 6 is electrically connected to the numerical analysis device 5. The numerical analysis device 5 may be incorporated in the control device 6. The control device 6 is electrically connected to the first flocculant injection device 4 and the third flocculant injection device 53.

In the flocculation apparatus having such a configuration, first, the second supply device 35 and the first supply device 7 are operated to supply the stock solution containing suspended solids to the first flocculation tank agitator 12 and the high-speed agitator 1. To do. The stock solution stirred to form flocs in the first flocculating tank stirrer 12 is supplied to the high speed stirrer 1 and mixed with the second flocculant in the high speed stirrer 1. The stock solution stirred at high speed by the high-speed stirrer 1 is sent to the optical measuring device 3. The optical measuring device 3 performs an optical measurement of the stock solution stirred at a high speed to obtain an optical measurement value. The optical measurement value obtained from the optical measurement device 3 is sent to the numerical analysis device 5 as described above. The numerical analysis device 5 numerically analyzes the optical measurement value and acquires the numerical analysis value. The obtained numerical analysis value is sent to the control device 6. The control device 6 determines an appropriate injection rate of the second flocculant based on the numerical analysis value by the method as described above.

The determined injection rate of the second flocculant is sent to the third flocculant injection device 53. Then, the first supply device 7 is stopped and the third supply device 56 is operated. That is, the supply devices that operate are the second supply device 35 and the third supply device 56. Thereby, the stock solution stored in the stock solution storage tank 10 is supplied to the first flocculation tank stirrer 12 and the second flocculation tank stirrer 21. The injection rate of the second flocculant injected from the second flocculant storage tank 23 into the second flocculant stirrer 21 is the injection rate determined previously. Thereby, the injection rate of the second flocculant injected into the stock solution containing the suspended substance is automatically controlled. An appropriate floc is formed by injecting the second flocculant at an appropriate injection rate. The stock solution containing floc is sent to the precipitation tank 20 and separated into a processed solution and a concentrated stock solution.

Note that the third supply device 56 can be omitted. In this case, a height difference is provided between the first flocculating tank stirrer 12 and the second flocculating tank stirrer 21. By utilizing the position head difference resulting from this height difference, the stock solution is supplied from the first agglomeration tank agitator 12 to the second agglomeration tank agitator 21 (natural flow method).

FIG. 15 is a schematic view showing still another embodiment of the aggregating apparatus of the present invention. The aggregating apparatus shown in FIG. 15 is an embodiment in which the aggregating apparatus shown in FIG. 13 is combined with the configuration of the aggregating apparatus shown in FIG. That is, the aggregating apparatus shown in FIG. 15 can determine an appropriate injection rate of the first flocculant and an appropriate injection rate of the second flocculant. Other configurations that are not particularly described are the same as those in the embodiment shown in FIGS. 13 and 14, and thus the corresponding components are denoted by the same reference numerals, and detailed description thereof is omitted.

In order to determine an appropriate injection rate of the first flocculant, the flocculant includes the high-speed stirrer 1 as described above. Further, in order to determine an appropriate injection rate of the second aggregating agent, the aggregating apparatus includes a high-speed agitator 60. Hereinafter, the high-speed stirrer 1 is referred to as the first high-speed stirrer 1, and the high-speed stirrer 60 is referred to as the second high-speed stirrer 60.

In order to determine the appropriate injection rate of the first flocculant, the flocculant has the first high-speed stirrer 1, the first optical measuring device 3, the first numerical value as described above. An analysis device 5 and a first control device 6 are provided. A first supply pipe 19 for supplying the stock solution to the first high-speed stirrer 2 of the first high-speed stirrer 1 is branched from the supply source pipe 18 and extends to the first supply pipe 19. The supply device 7 is arranged. The stock solution containing suspended solids is supplied to the first high-speed stirring tank 2 by the first supply device 7.

A first discharge pipe 28 through which the stock solution discharged from the high-speed stirring tank 2 flows is connected to the high-speed stirring tank 2, and the first optical measuring device 3 is arranged in the first discharge pipe 28. Yes. The first optical measurement device 3 is, for example, the above-described measurement device that measures the transmitted light intensity or the measurement device that measures the scattered light intensity. An optical measurement device that measures transmitted light intensity and an optical measurement device that measures scattered light intensity may be arranged in series. The optical measuring device 3 may be a measuring device capable of measuring transmittance, intensity of diffracted light, intensity of diffracted / scattered light, absorbance, intensity of reflected light, and the like.

A first flocculant storage tank 11 for storing the first flocculant is provided, and a first flocculant supply pipe 26 extending from the first flocculant storage tank 11 is connected to the first high-speed stirring tank 2. A first flocculant injection device 4 is disposed in the first flocculant supply pipe 26. The first flocculant injection device 4 is a device that injects the first flocculant at a predetermined injection rate into a stock solution containing suspended solids. The first flocculant injection device 4 is, for example, a pump, a valve, or a combination of a pump and a valve.

The second flocculant supply pipe 36 extending from the first flocculant storage tank 11 is connected to the first flocculant agitation tank 37 of the first agglomeration tank agitator 12. A second flocculant injection device 45 is disposed in the second flocculant supply pipe 36. The second flocculant injection device 45 is a device for injecting the first flocculant at a predetermined injection rate into the stock solution containing suspended solids. The second flocculant injection device 45 is, for example, a pump, a valve, or a combination of a pump and a valve. In the embodiment shown in FIG. 15, the first flocculant supply pipe 26 is directly connected to the first flocculant reservoir 11, but the first flocculant reservoir 11 and the second flocculant injection You may branch from between the apparatuses 45. Alternatively, the first flocculant supply pipe 26 may be branched from between the second flocculant injection device 45 and the first flocculant stirring tank 37.

A first numerical analysis device 5 is electrically connected to the first optical measurement device 3, and a first control device 6 is electrically connected to the first numerical analysis device 5. The first numerical analysis device 5 may be incorporated in the first control device 6. The first controller 6 is electrically connected to the first flocculant injection device 4 and the second flocculant injection device 45.

15, a second flocculating tank stirrer 21 is connected in series with the first flocculating tank stirrer 12. The first agglomeration tank agitator 12 and the second agglomeration tank agitator 21 are connected by a connection pipe 55, and a third supply pipe 57 extending to the second high-speed agitator 60 is branched from the connection pipe 55. The second high-speed stirrer 60 includes a second high-speed stirring tank 61 to which a stock solution containing suspended solids is supplied, a second high-speed stirring blade 62 that stirs the stock solution containing suspended solids, and a second high-speed stirring. And a second high-speed motor 63 as a driving device for rotating the blades 62. A third supply pipe 57 is connected to the second high-speed stirring tank 61 of the second high-speed stirrer 60, and the third supply pipe 57 is supplied with a stock solution containing suspended solids at a predetermined flow rate. A fourth supply device 65 that supplies the high-speed stirring tank 61 is disposed. The fourth supply device 65 is, for example, a pump, a valve, or a combination of a pump and a valve. In the embodiment shown in FIG. 15, the third supply pipe 57 is branched from between the first agglomeration stirring tank 37 and the third supply device 56. You may branch from between the 2nd aggregation stirring tank 47. Alternatively, the third supply pipe 57 may be directly connected to the first aggregation stirring tank 37.

The second flocculating agent 47 is supplied to the second flocculating and stirring tank 47, which is different from the first flocculating agent supplied to the first high-speed stirring tank 2 and the first flocculating and stirring tank 37. The second flocculant is stored in the second flocculant storage tank 23. A third flocculant supply pipe 52 for supplying the second flocculant from the second flocculant reservoir 23 to the second flocculent agitation tank 47 is provided from the second flocculant reservoir 23 to the third high-speed agitation tank. 47. The third flocculant supply pipe 52 is provided with a third flocculant injection device 53, and the second flocculant is injected into the second flocculant stirring tank at a predetermined injection rate by the third flocculant injection device 53. 47 is injected. The third flocculant injection device 53 is, for example, a pump, a valve, or a combination of a pump and a valve.

The fourth flocculant supply pipe 58 extends from the second flocculant storage tank 23 to the second high-speed agitation tank 61 of the second high-speed agitator 60. A fourth flocculant injection device 66 is disposed in the fourth flocculant supply pipe 58. The fourth flocculant injecting device 66 injects the second flocculant into the second high-speed stirring tank 61 at a predetermined injection rate. The fourth flocculant injection device 66 is, for example, a pump, a valve, or a combination of a pump and a valve. In the embodiment shown in FIG. 15, the fourth flocculant supply pipe 58 is directly connected to the second flocculant reservoir 23, but the second flocculant reservoir 23 and the third flocculant injection You may branch from between the apparatuses 53. FIG. Alternatively, the fourth flocculant supply pipe 58 may be branched from between the third flocculant injection device 53 and the second flocculent stirring tank 47.

A third discharge pipe 69 through which the stock solution discharged from the second high-speed stirring tank 61 flows is connected to the second high-speed stirring tank 61, and the third discharge pipe 69 has a second optical measurement. A device 68 is arranged. The second optical measuring device 68 disposed on the downstream side of the second high-speed stirrer 60 has the same configuration as the first optical measuring device 3, and for example, a measuring device that measures the above-described transmitted light intensity. Alternatively, a measuring device that measures scattered light intensity can be used.

A second numerical analysis device 70 is electrically connected to the second optical measurement device 68, and a second control device 71 is electrically connected to the second numerical analysis device 70. The second numerical analysis device 70 may be incorporated in the second control device 71. The second control device 71 is electrically connected to the third flocculant injection device 53 and the fourth flocculant injection device 66.

In the aggregating apparatus having such a configuration, first, the first supply device 7 is operated to supply a stock solution containing suspended substances in the stock solution storage tank 10 to the first high-speed stirrer 1. The first flocculant is supplied to the first high-speed stirring tank 2 of the first high-speed stirrer 1 by the first flocculant injection device 4. In the first high-speed stirring tank 2, the stock solution and the flocculant are mixed at a high-speed rotation in which the rotation speed of the first high-speed stirring blade 8 is 500 min ⁻¹ or more.

The stock solution stirred at high speed by the first high-speed stirrer 1 is sent to the first optical measuring device 3. The first optical measuring device 3 performs an optical measurement of the stock solution stirred at high speed, and acquires an optical measurement value. The optical measurement value obtained from the first optical measurement device 3 is sent to the first numerical analysis device 5 as described above. The first numerical analysis device 5 performs numerical analysis on the optical measurement value and acquires a numerical analysis value. The obtained numerical analysis value is sent to the first control device 6. The first control device 6 determines an appropriate injection rate of the first flocculant based on the numerical analysis value by the method as described above.

The determined injection rate of the first flocculant is sent from the first control device 6 to the second flocculant injection device 45. Then, the first supply device 7 is stopped, and the second supply device 35 and the fourth supply device 65 are operated. The stock solution in the stock solution storage tank 10 is sent to the first agglomeration tank stirrer 12. A first flocculant is injected into the first aggregating tank agitator 12 at the injection rate determined as described above, and the flocculant is mixed with the stock solution, whereby flocs are primarily formed.

The stock solution containing flocs primarily formed using the first flocculant is supplied to the second high-speed stirrer 60 by the fourth supply device 65. The second flocculant is supplied to the second high-speed stirring tank 61 of the second high-speed stirrer 60 by the fourth flocculant injection device 66. In the second high-speed stirring tank 61, the stock solution and the second aggregating agent are mixed at a high-speed rotation in which the rotation speed of the second high-speed stirring blade 62 is 500 min ⁻¹ or more.

The stock solution stirred at high speed by the second high speed stirrer 60 is sent to the second optical measuring device 68. The second optical measuring device 68 performs an optical measurement of the stock solution stirred at a high speed by the second high-speed stirrer 60 and acquires an optical measurement value. The optical measurement value obtained from the second optical measurement device 68 is sent to the second numerical analysis device 70 as described above. The second numerical analysis device 70 performs numerical analysis on the optical measurement value and acquires a numerical analysis value. The obtained numerical analysis value is sent to the second control device 71. The second control device 71 determines an appropriate injection rate of the second flocculant based on the numerical analysis value by the method as described above.

The determined injection rate of the second flocculant is sent from the second control device 71 to the third flocculant injection device 53. Then, the fourth supply device 65 is stopped and the third supply device 56 is operated. In other words, the supply devices that operate are the second supply device 35 and the third supply device 56. Thereby, the stock solution stored in the stock solution storage tank 10 is supplied to the first flocculation tank stirrer 12 and the second flocculation tank stirrer 21.

The injection rate of the first coagulant injected into the first coagulation tank agitator 12 is the injection rate determined in advance. Similarly, the injection rate of the second flocculant injected into the second aggregating tank stirrer 21 is the previously determined injection rate. Thereby, the injection rates of the first flocculant and the second flocculant injected into the stock solution containing the suspended substance are automatically controlled. By injecting the first flocculant and the second flocculant at an appropriate flocculant injection rate, an appropriate floc is formed in the stock solution. The stock solution containing the flock is sent to the precipitation tank 20 and separated into a treated solution and a concentrated stock solution.

In the embodiment shown in FIG. 15, the third supply device 56 can be omitted. In this case, a height difference is provided between the first flocculating tank stirrer 12 and the second flocculating tank stirrer 21. By utilizing the position head difference resulting from this height difference, the stock solution is supplied from the first agglomeration tank agitator 12 to the second agglomeration tank agitator 21 (natural flow method).

FIG. 16 is a schematic view showing still another embodiment of the aggregating apparatus of the present invention. The aggregating apparatus shown in FIG. 16 has a configuration in which a stock solution storage tank 10, a high-speed agitator 1, an optical measuring device 3, an aggregating tank agitator 12, and a dehydrator 14 are connected in this order. The stock solution storage tank 10 stores a stock solution containing suspended solids. A supply source pipe 18 extending from the stock solution storage tank 10 is connected to the high speed stirring tank 2 of the high speed stirrer 1, and the stock solution stored in the stock solution storage tank 10 is supplied to the high speed stirring tank 2 at a predetermined flow rate. A supply device 7 is arranged.

A flocculant storage tank 11 for storing the flocculant is provided, and a first flocculant supply pipe 26 extending from the flocculant storage tank 11 is connected to the supply source pipe 18. The flocculant injection device 4 is disposed in the first flocculant supply pipe 26. The flocculant injection device 4 is a device that injects the flocculant at a predetermined injection rate into the stock solution containing suspended solids.

A second flocculant supply pipe 36 extending from the flocculant storage tank 11 is connected to the flocculant agitation tank 37. A second flocculant injection device 45 is disposed in the second flocculant supply pipe 36. The second flocculant injection device 45 is a device that injects the flocculant into the stock solution containing the suspended substance at a predetermined injection rate. In the embodiment shown in FIG. 16, the second flocculant supply pipe 36 is directly connected to the flocculant storage tank 11, but from between the flocculant storage tank 11 and the first flocculant injection device 4. It may branch off. Alternatively, the second flocculant supply pipe 36 may be branched from between the first flocculant injection device 4 and the supply source pipe 18.

The high-speed stirrer 1 and the coagulation tank stirrer 12 are connected in series by a connection pipe 55, and the optical measuring device 3 is arranged in the connection pipe 55. Therefore, the stock solution measured by the optical measuring device 3 is a stock solution stirred at high speed by the high-speed stirrer 1. The stock solution stirred at high speed by the high-speed stirrer 1 is supplied to the coagulation tank stirrer 12. The stock solution supplied to the aggregation stirring tank 37 of the aggregation tank agitator 12 is mixed with the aggregation agent supplied from the aggregation agent storage tank 11 in the aggregation stirring tank 37.

A numerical analysis device 5 is electrically connected to the optical measurement device 3, and a control device 6 is electrically connected to the numerical analysis device 5. The numerical analysis device 5 may be incorporated in the control device 6. The control device 6 is electrically connected to the first flocculant injection device 4 and the second flocculant injection device 45.

In such a configuration, the optical measurement value obtained from the optical measurement device 3 is sent to the numerical analysis device 5 as described above. The numerical analysis device 5 numerically analyzes the optical measurement value and acquires the numerical analysis value. The obtained numerical analysis value is sent to the control device 6. The control device 6 determines an appropriate injection rate of the flocculant based on the numerical analysis value by the method as described above. The injection rate determined by the control device 6 is sent to the first coagulant injection device 4 and the second coagulant injection device 45. The first flocculant injection device 4 and the second flocculant injection device 45 inject the flocculant into the stock solution containing the suspended substance at the determined injection rate. Thereby, the injection | pouring rate of the coagulant | flocculant inject | poured into the stock solution containing a suspended solid is controlled automatically. The injection rate determined by the control device 6 may be the injection rate of the flocculant injected by the first flocculant injection device 4 or the flocculant injected by the second flocculant injection device 45. It is good also as an injection rate. Further, the injection rate determined by the control device 6 is the sum of the injection rate of the flocculant injected by the first flocculant injection device and the injection rate of the flocculant injected by the second flocculant injection device 45. It is good also as an injection rate.

FIG. 17 is a schematic view showing still another embodiment of the aggregating apparatus of the present invention. In the aggregating apparatus shown in FIG. 17, a settling tank 20 is provided instead of the dehydrator 14. Since the other configuration is the same as that of the embodiment shown in FIG. 16, the corresponding components are denoted by the same reference numerals, and detailed description thereof is omitted. The floc in the undiluted solution supplied to the settling tank 20 settles toward the bottom of the settling tank 20 due to its own weight, so that the undiluted solution containing the floc is a concentrated undiluted solution in which the floc exists at a high concentration (for example, concentrated sludge) And the processed liquid without floc. By providing the precipitation tank 20 in this way, it is possible to separate the floc and the processed liquid.

FIG. 18 is a schematic view showing still another embodiment of the aggregating apparatus of the present invention. In the aggregating apparatus shown in FIG. 18, the fifth supply pipe 80 is branched from the connection pipe 55, and the optical measurement apparatus 3 and the first solution for supplying the stock solution to the optical measurement apparatus 3 are supplied to the fifth supply pipe 80. 5 supply devices 81 are arranged. The fifth supply device 81 is, for example, a pump, a valve, or a combination of a pump and a valve. Since the other configuration is the same as that of the embodiment shown in FIG. 16, the corresponding components are denoted by the same reference numerals, and detailed description thereof is omitted.

In this embodiment, first, the first supply device 7 and the fifth supply device 81 are operated, and the stock solution mixed with the flocculant by the high-speed stirrer 1 is supplied to the optical measurement device 3. The optical measurement value obtained from the optical measurement device 3 is sent to the numerical analysis device 5 as described above. The numerical analysis device 5 numerically analyzes the optical measurement value and acquires the numerical analysis value. The obtained numerical analysis value is sent to the control device 6. The control device 6 determines an appropriate injection rate of the flocculant based on the numerical analysis value by the method as described above. The injection rate determined by the control device 6 is sent to the first coagulant injection device 4 and the second coagulant injection device 45. The first flocculant injection device 4 and the second flocculant injection device 45 inject the flocculant into the stock solution containing the suspended substance at the determined injection rate. Thereby, the injection | pouring rate of the coagulant | flocculant inject | poured into the stock solution containing a suspended solid is controlled automatically.

Next, the fifth supply device 81 is stopped, and the stock solution that has passed through the high-speed stirrer 1 is supplied to the coagulation tank stirrer 12. The stock solution discharged from the coagulation tank stirrer 12 is supplied to the dehydrator 14 through the second discharge pipe 46, and is separated into the filtrate and the cake by the dehydrator 14.

FIG. 19 is a schematic view showing still another embodiment of the aggregating apparatus of the present invention. In the flocculating device shown in FIG. 19, the flocculating agent supplied to the stock solution from the first flocculating agent injection device 4 is supplied to the high-speed stirring tank 2 of the high-speed stirrer 1 instead of being supplied to the supply source pipe 18. . Since the other configuration is the same as that of the embodiment shown in FIG. 18, the corresponding components are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 20 is a schematic view showing still another embodiment of the aggregating apparatus of the present invention. In the flocculating apparatus shown in FIG. 20, instead of the flocculating agent supplied from the second flocculating agent injection device 45 to the stock solution being supplied to the flocculating stirrer tank 37 of the flocculating tank stirrer 12, the upstream side of the coagulating tank stirrer 12. Is supplied to a connecting pipe 55 arranged in Since the other configuration is the same as that of the embodiment shown in FIG. 18, the corresponding components are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 21 is a schematic view showing still another embodiment of the aggregating apparatus of the present invention. In the flocculating apparatus shown in FIG. 21, the flocculating tank stirrer 12 is omitted, and the connection pipe 55 extending from the high speed stirrer 1 is directly connected to the dehydrator 14. Further, the flocculant supplied from the second flocculant injection device 45 to the stock solution is supplied to the connection pipe 55. The dehydrator 14 of this embodiment is a dehydrator having a coagulation tank function for forming a flock. An example of the dehydrator 14 having a coagulation tank function is a centrifugal dehydrator.

FIG. 22 is a schematic view showing still another embodiment of the aggregating apparatus of the present invention. The aggregating apparatus shown in FIG. 22 has a diluent storage tank 85 that stores the diluent, and a diluent supply apparatus 86 that supplies the diluent stored in the diluent storage tank 85 to the stock solution stirred by the high-speed stirrer 1 at a predetermined flow rate. And comprising. A diluent supply pipe 87 extends from the diluent storage tank 85, and this diluent supply pipe 87 is connected to the discharge pipe 28 between the high-speed stirrer 1 and the optical measuring device 3. The diluent supply device 86 is disposed in the diluent supply pipe 87. Since the other configuration is the same as that of the embodiment shown in FIG. 8, the corresponding components are denoted by the same reference numerals, and detailed description thereof is omitted.

The diluent supply device 86 is a device that supplies the diluent to the stock solution at a predetermined flow rate before the stock solution stirred by the high-speed stirrer 1 is supplied to the optical measuring device 3. The diluent supply device 86 is, for example, a pump, a valve, or a combination of a pump and a valve. In this aggregating apparatus, the diluent is supplied from the diluent storage tank 85 to the stock solution stirred by the high-speed stirrer 1 by the diluent supply device 86. The stock solution diluted with the diluent is supplied to the optical measurement device 3, and optical measurement is performed by the optical measurement device 3.

The concentration of suspended solids or floc can be reduced by diluting the stirred stock solution with the diluent. In stock solutions with a high concentration of suspended solids, there is no difference between the optical measurement when floc is formed and the optical measurement when no floc is formed, and as a result, it is difficult to determine the injection rate of the flocculant. There are cases. For example, when measuring the transmitted light intensity of a stock solution having a high concentration of suspended solids with the optical measuring device 3, even if flocs are formed with an appropriate injection rate of the flocculant, there are almost no gaps between the flocs. As shown in FIG. 2A, the transmitted light intensity may become substantially constant. On the other hand, when diluting the stock solution stirred by the high-speed stirrer 1 with the diluent, the gap between the flocks can be increased, so that light is transmitted through the gap between the flocks, as shown in FIG. A plurality of transmitted light intensity peaks are measured. As a result, there is a difference between the transmitted light intensity when the floc is formed and the transmitted light intensity when the floc is not formed, and an appropriate injection rate can be determined. As the diluent, pure water, tap water, industrial water, ground water, treated water for various wastewater treatment, seawater, and the like can be used.

The diluting liquid storage tank 85 and the diluting liquid supply device 86 shown in FIG. 22 may be arranged in the aggregating apparatus according to the embodiment described with reference to FIGS. In this case, the diluent supply pipe 87 that extends from the diluent storage tank 85 and in which the diluent supply device 86 is disposed is the discharge pipe 28 between the high-speed stirrer 1 and the optical measuring device 3 and / or the high-speed stirrer 60. Connected to a discharge pipe 69 between the optical measuring devices 68.

The embodiment of the aggregating apparatus has been described with reference to FIGS. In these embodiments, the following method can be used to change the injection rate of the flocculant injected into the stock solution containing suspended solids supplied to the high-

speed stirring tanks

2 and 61.

By changing the flow rate of the flocculant injected into the stock solution from the

flocculant injection devices

4 and 66 in a state where the flow rate of the stock solution supplied by the supply devices 7 and 65 is controlled to be constant, The injection rate of the flocculant injected into the stock solution containing the suspended solids to be supplied can be changed. Alternatively, in the state where the flow rate of the flocculant injected from the

flocculant injection devices

4 and 66 is controlled to be constant, the flow rate of the stock solution supplied by the supply devices 7 and 65 is changed, so that You may change the injection | pouring rate of the coagulant | flocculant inject | poured into the stock solution containing the suspended solids supplied. Alternatively, in order to change the injection rate of the flocculant injected into the stock solution containing suspended solids supplied to the high-

speed stirring tanks

2, 61, the flow rate of the stock solution supplied by the supply devices 7, 65 and the flocculant injection Both the flow rate of the flocculant injected into the stock solution from the

devices

4 and 66 may be changed.

Hereinafter, the present invention will be described in more detail based on the following experimental results.

First, the first experiment will be described. The procedure of the first experiment is as follows. First, a flocculant is poured into a stock solution (sludge) containing suspended substances (injection step). The stock solution and the flocculant are mixed by rapidly stirring the stock solution into which the flocculant has been injected (stirring step). The transmitted light intensity of the stock solution stirred at high speed is measured to obtain an optical measurement value (optical measurement step). As a numerical analysis value of the obtained transmitted light intensity, an average value, dispersion, standard deviation, and peak area of the transmitted light intensity are calculated (numerical analysis step). The injection process, stirring process, optical measurement process, and numerical analysis process are repeated at different injection rates of the flocculant, and the relationship between the obtained numerical analysis values and the appropriate injection ratio is examined (injection rate determination process) . In order to determine an appropriate injection rate, a stock solution containing suspended solids aggregated with a flocculant was dehydrated with a dehydrator, and the moisture content of the obtained dehydrated cake was used as an index.

The stock solution containing suspended solids used in the first experiment is sludge A. Sludge A is an anaerobic digested sludge from a sewage treatment plant. The TS (Total Solids) of sludge A was 13.2 g / L. TS is an evaporation residue and is a concentration of a substance remaining when the sludge A is evaporated to dryness at 105 to 110 ° C. The measurement method conformed to the sewage test method.

The flocculant used in the first experiment is a cationic polymer flocculant a (DAA polymer flocculant). The solution of the flocculant is an aqueous solution obtained by dissolving the flocculant in water, and the concentration of the flocculant means the concentration of the flocculant in the aqueous solution.

In the first experiment, a solution of the cationic polymer flocculant a was injected into the sludge A (sludge flow rate 1.0 m ³ / h). Sludge A into which the cationic polymer flocculant a was injected was mixed using a high-speed stirrer (stirring section volume 0.8 L) in which the rotation speed of the stirring blade was set to 1000 min ⁻¹ . Subsequently, the transmitted light intensity of the sludge A stirred at high speed was measured for a certain time. Next, the average value, dispersion, standard deviation, and peak area of the obtained transmitted light intensity data were calculated. These operations were performed at multiple injection rates of flocculant.

On the other hand, in order to determine an appropriate injection rate of the flocculant, a solution of the cationic polymer flocculant a was injected into the sludge A (sludge flow rate 1.0 m ³ / h). Sludge A into which the cationic polymer flocculant a was injected was mixed using a stirrer (stirring tank volume 300 L) in which the rotation speed of the stirring blade was set to 33 min ⁻¹ to form floc. Finally, the sludge A containing floc was dehydrated with a screw press dehydrator, and the water content (%) of the obtained dehydrated cake was measured. These operations were performed at multiple injection rates. The results of the first experiment are shown in Table 1.

It can be seen that the average value of transmitted light intensity, dispersion, standard deviation, and peak area all take the maximum value when the injection rate of the flocculant is 1.1% (vs. TS). On the other hand, from the results of the screw press dehydrator, it can be seen that the proper injection rate is 1.1% (vs. TS). From these results, it was found that the injection rate of the flocculant that can most reduce the moisture content of the cake can be determined based on the average value, the dispersion, the standard deviation, and the maximum peak area of the transmitted light intensity. More specifically, it has been found that the injection rate of the flocculant that can reduce the moisture content of the cake can be determined based on the flocculant injection rate at which the average value, dispersion, standard deviation, and peak area values of the transmitted light intensity are maximized.

Next, the second experiment will be described. The procedure of the second experiment is as follows. First, a flocculant is poured into a stock solution (sludge) containing suspended substances (injection step). The stock solution and the flocculant are mixed by rapidly stirring the stock solution into which the flocculant has been injected (stirring step). The transmitted light intensity of the stock solution stirred at high speed is measured to obtain an optical measurement value (optical measurement step). As a numerical analysis value of the obtained transmitted light intensity, an average value, dispersion, standard deviation, and peak area of the transmitted light intensity are calculated (numerical analysis step). The injection process, stirring process, optical measurement process, and numerical analysis process are repeated at different injection rates of the flocculant, and the relationship between the obtained numerical analysis values and the appropriate injection ratio is examined (injection rate determination process) . In order to determine an appropriate injection rate, a stock solution containing suspended solids aggregated with a flocculant was dehydrated with a dehydrator, and the moisture content of the obtained dehydrated cake was used as an index.

The stock solution containing suspended solids used in the second experiment is sludge B, which is different from the sludge A used in the first embodiment. Sludge B is mixed raw sludge (mixture of primary sludge and surplus sludge) in a sewage treatment plant. The TS of sludge B is 14.2 g / L. The measurement method conformed to the sewage test method.

The flocculant used in the second experiment is cationic polymer flocculant b (DAA polymer flocculant). The solution of the flocculant is an aqueous solution obtained by dissolving the flocculant in water, and the concentration of the flocculant means the concentration of the flocculant in the aqueous solution.

In the second experiment, a solution of the cationic polymer flocculant b was injected into sludge B (sludge flow rate 1.5 m ³ / h). Sludge B into which the cationic polymer flocculant b was injected was mixed using a high-speed stirrer (stirring unit volume 0.8 L) in which the rotation speed of the stirring blade was set to 500 min- ¹ . Subsequently, the transmitted light intensity of the sludge B stirred at high speed was measured for a certain time. Next, the average value, dispersion, standard deviation, and peak area of the obtained transmitted light intensity data were calculated. These operations were performed at multiple injection rates of flocculant.

On the other hand, in order to determine an appropriate injection rate of the flocculant, a solution of the cationic polymer flocculant b was injected into the sludge B (sludge flow rate 1.5 m ³ / h). Sludge B into which the cationic polymer flocculant b was injected was mixed using a stirrer (stirring tank volume 300 L) in which the rotation speed of the stirring blade was set to 33 min ⁻¹ to form floc. Finally, the sludge B containing floc was dehydrated with a screw press dehydrator, and the moisture content (%) of the obtained dehydrated cake was measured. The above operation was carried out at a plurality of flocculant injection rates. The results of the second experiment are shown in Table 2.

It can be seen that the average value of transmitted light intensity, dispersion, standard deviation, and peak area all take the maximum value when the injection rate of the flocculant is 0.70% (vs. TS). On the other hand, from the results of the screw press dehydrator, it can be seen that when the flocculant injection rate is 0.70% (vs. TS) or less, the moisture content of the cake is greatly reduced every time the injection rate is increased by about 0.1%. . In contrast, when the injection rate of the flocculant is 0.70% (vs. TS) or more, even if the injection rate increases by about 0.1%, the moisture content of the cake is reduced, but it is almost the same. I understand. From these results, it was found that the coagulant injection rate enabling the most efficient dehydration can be determined based on the average value, the dispersion, the standard deviation, and the peak area of the transmitted light intensity. More specifically, it was found that the injection rate of the flocculant capable of performing the most efficient dehydration can be determined based on the average value, the dispersion, the standard deviation, and the maximum peak area of the transmitted light intensity.

Next, the third experiment will be described. The procedure of the third experiment is as follows. First, a flocculant is injected into a stock solution (raw water for water purification treatment) containing suspended solids (injection step). The stock solution and the flocculant are mixed by rapidly stirring the stock solution into which the flocculant has been injected (stirring step). Laser diffraction / scattered light of the stock solution stirred at high speed is measured to obtain optical measurement values (optical measurement step). The obtained laser diffraction / scattered light data is numerically analyzed to calculate the average floc particle diameter of the floc (numerical analysis step). The injection process, stirring process, optical measurement process, and numerical analysis process are repeated at different injection rates of the flocculant, and the relationship between the obtained numerical analysis values and the appropriate injection ratio is examined (injection rate determination process) . In order to determine an appropriate injection rate, a stock solution containing suspended solids aggregated with a coagulant was coagulated and precipitated, and the quality of the obtained treated water was used as an index.

The stock solution containing suspended solids used in the third experiment is raw water C for water purification. The turbidity and chromaticity of the raw water C are 50 degrees and 80 degrees, respectively. The measuring method was based on the water test method.

The flocculant used in the third experiment was polyaluminum chloride, and a 10 wt% polyaluminum chloride aqueous solution (in terms of aluminum oxide) was used as the flocculant solution. The flocculant concentration means the concentration of the flocculant in the aqueous solution.

In the third experiment, an aqueous solution of polyaluminum chloride was injected into raw water C (raw water flow rate 1.0 m ³ / h) for water purification treatment. Raw water C into which an aqueous solution of polyaluminum chloride was poured was mixed using a high-speed stirrer (stirring unit volume 0.8 L) in which the rotation speed of the stirring blade was set to 500 min ⁻¹ . Next, laser diffraction / scattered light of the raw water C stirred at high speed was measured for a certain period of time. Next, the average floc particle diameter was calculated from the obtained laser diffraction / scattered light data. These operations were performed at multiple injection rates of flocculant.

On the other hand, a jar test was performed to determine an appropriate injection rate of the flocculant. In the jar test, an aqueous solution of polyaluminum chloride was poured into 500 mL of raw water C, the rotation speed during stirring was set to 130 min ⁻¹ , and raw water C and an aqueous solution of polyaluminum chloride were mixed for 3 minutes. Further, the rotation speed at the time of stirring was set to 30 min ⁻¹ , and raw water C and an aqueous solution of polyaluminum chloride were mixed for 10 minutes to form a floc. Finally, it was left to stand for 5 minutes, and a supernatant was collected as treated water, and turbidity and chromaticity were measured. The above operation was carried out at a plurality of flocculant injection rates.

The results of the third experiment are shown in Table 3 and FIG. FIG. 23 is a graph plotting the results of the third experiment. In FIG. 23, the horizontal axis represents the injection rate of the flocculant, and the vertical axis represents the average floc particle size. FIG. 23 shows an approximate curve (cubic curve) obtained from the experimental results.

23. From the approximate curve in FIG. 23, it can be seen that the average floc particle diameter takes the maximum value when the injection rate of the flocculant is 50 to 60 mg / L (in terms of 10 wt% aqueous solution). On the other hand, it can be seen from the results of the jar test that the proper injection rate is 60 mg / L (in terms of 10 wt% aqueous solution). From these results, it was found that the injection rate of the flocculant that can obtain the best treated water can be determined based on the average floc particle size. More specifically, it has been found that the injection rate at which the best treated water quality can be obtained can be determined based on the injection rate of the flocculant having the maximum average floc particle size.

Next, the fourth experiment will be described. The procedure of the fourth experiment is as follows. First, a flocculant is poured into a stock solution (sludge) containing suspended substances (injection step). The stock solution and the flocculant are mixed by rapidly stirring the stock solution into which the flocculant has been injected (stirring step). The sludge stirred at high speed is diluted with a diluent (dilution step). The transmitted light intensity of the diluted stock solution is measured to obtain an optical measurement value (optical measurement step). As a numerical analysis value of the obtained transmitted light intensity, dispersion, standard deviation, and peak area of the transmitted light intensity are calculated (numerical analysis step). Repeat the injection process, the agitation process, the dilution process, the optical measurement process, and the numerical analysis process at different injection rates of the flocculant, and examine the relationship between the obtained numerical analysis values and the appropriate injection rate (injection rate) Decision process). In order to determine an appropriate injection rate, a stock solution containing suspended solids aggregated with a flocculant was dehydrated with a dehydrator, and the moisture content of the obtained dehydrated cake was used as an index.

The stock solution containing suspended solids used in the fourth experiment is sludge D. Sludge D is a mixed raw sludge (mixture of primary sludge and excess sludge) in a sewage treatment plant. The sludge D TS is 25.4. g / L. The measurement method conformed to the sewage test method.

The flocculant used in the fourth experiment is a cationic polymer flocculant d (DAA polymer flocculant). The solution of the flocculant is an aqueous solution obtained by dissolving the flocculant in water, and the concentration of the flocculant means the concentration of the flocculant in the aqueous solution.

In the fourth experiment, a solution of the cationic polymer flocculant d was injected into the sludge D (sludge flow rate 1.8 L / min). Sludge D into which the cationic polymer flocculant d was injected was mixed using a high-speed stirrer (stirring unit volume 0.5 L) in which the rotation speed of the stirring blade was set to 600 min ⁻¹ . Next, the sludge D stirred at high speed was diluted with a diluent (diluent flow rate 2.6 L / min). As the diluting liquid, sand filtered water of sewage treated water was used. Next, the transmitted light intensity of the diluted sludge D was measured for a certain time. Next, the dispersion, standard deviation, and peak area of the obtained transmitted light intensity data were calculated. These operations were performed at multiple injection rates of flocculant.

On the other hand, in order to determine an appropriate injection rate of the flocculant, a solution of the cationic polymer flocculant d was injected into 250 mL of sludge D. Sludge D into which the cationic polymer flocculant d was injected was mixed using a stirrer (stirring tank volume 300 L) in which the rotation speed of the stirring blade was set to 33 min-1 to form floc. Finally, the sludge D containing floc was dehydrated with a belt press dehydrator, and the water content (%) of the dehydrated cake obtained was measured. These operations were performed at multiple injection rates of flocculant. The results of the fourth experiment are shown in Table 4.

It can be seen that all of the dispersion, standard deviation, and peak area of transmitted light intensity take a maximum value when the injection rate of the flocculant is 0.58% (vs. TS). On the other hand, from the results of the belt press dehydrator, it is understood that when the flocculant injection rate is 0.58% (vs. TS) or less, the moisture content of the cake is greatly reduced as the injection rate is increased. In contrast, it can be seen that when the flocculant injection rate is 0.58% (vs. TS) or more, the moisture content of the cake hardly changes even if the injection rate increases. From these results, it was found that the coagulant injection rate enabling the most efficient dehydration can be determined based on the dispersion of the transmitted light intensity, the standard deviation, and the maximum value of the peak area. More specifically, it has been found that the injection rate of the flocculant capable of the most efficient dehydration can be determined based on the flocculant injection rate at which the values of transmitted light intensity dispersion, standard deviation, and peak area are maximized.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Is possible.

The present invention can be used in a method for determining an appropriate injection rate of a flocculant injected into a stock solution containing suspended solids.

DESCRIPTION OF SYMBOLS 1 1st high-speed stirrer 2 1st high-speed stirring tank 3 1st optical measurement apparatus 4 1st flocculant injection apparatus 5 1st numerical analysis apparatus 6 1st control apparatus 7 1st supply apparatus 8 1st 1 high-speed stirring blade 9 first high-speed motor 10 stock solution storage tank 11 first flocculant storage tank 12 first flocculant tank stirrer 14 dehydrator 18 source pipe 19 first supply pipe 20 sedimentation tank 21 second flocculant tank Stirrer 23 Second flocculant storage tank 25 Second supply pipe 26 First flocculant supply pipe 28 First discharge pipe 35 Second supply device 36 Second flocculant supply pipe 37 First flocculant stirring tank 38 First aggregating tank agitating blade 39 First aggregating tank motor 40 Transparent window 41 Light source 42 Photo detector 43 Light source 44 Photo detector 45 Second coagulant injection device 46 Second discharge distribution 47 second agglomeration agitation tank 48 second agglomeration tank agitation blade 49 second agglomeration tank motor 50 data logger 52 third aggregating agent supply piping 53 third aggregating agent injection device 55 connection piping 56 third supply device 57 3rd supply piping 58 4th flocculant supply piping 60 2nd high speed stirrer 61 2nd high speed stirring tank 62 2nd high speed stirring blade 63 2nd high speed motor 65 4th supply apparatus 66 4th Flocculant injection device 68 Second optical measurement device 69 Third discharge piping 70 Second numerical analysis device 71 Second control device 80 Fifth supply piping 81 Fifth supply device 85 Diluent storage tank 86 Diluent Supply device 87 Diluent supply piping

Claims

An injection step of injecting a flocculant into a stock solution containing suspended solids;
A step of stirring the stock solution by flowing the stock solution into which the flocculant is injected into a high-speed stirrer and rotating the stirring blade of the high-speed stirrer at a rotation speed of 500 min −1 or more;
An optical measurement step of irradiating the stirred stock solution with light to obtain optical measurement values;
Numerical analysis of the optical measurement value to obtain a numerical analysis value; and
And an injection rate determining step for determining an appropriate injection rate of the flocculant based on the numerical analysis value.
The injection rate determination step includes
Based on the numerical analysis value, determine whether the injection rate of the flocculant is appropriate,
The injection step, the stirring step, the optical measurement step, and the numerical analysis step are repeated while changing the injection rate until an appropriate injection rate of the flocculant is determined. The aggregation method according to claim 1.
The change in the injection rate is to change either or both of a flow rate of the stock solution flowing into the high-speed stirrer and a flow rate of the flocculant injected into the stock solution. Aggregating method as described in
The aggregation method according to any one of claims 1 to 3, wherein the optical measurement step is a step of measuring the transmitted light intensity by irradiating the stirred stock solution with light.
The aggregation method according to any one of claims 1 to 3, wherein the optical measurement step is a step of measuring the scattered light intensity by irradiating the stirred stock solution with light.
The optical measurement step is a step of irradiating the stirred stock solution with light to measure both transmitted light intensity and scattered light intensity. Aggregation method.
The aggregation method according to any one of claims 1 to 6, wherein the dispersion of the optical measurement value is used as the numerical analysis value.
The aggregation method according to any one of claims 1 to 6, wherein a peak area of the optical measurement value is used as the numerical analysis value.
The aggregation method according to any one of claims 1 to 6, wherein a standard deviation of the optical measurement value is used as the numerical analysis value.
The aggregation method according to claim 1, wherein the numerical analysis value is a particle size of floc of the suspended substance.
The injection rate determination step includes
Obtaining a plurality of numerical analysis values by repeating the injection step, the stirring step, the optical measurement step, and the numerical analysis step a plurality of times while changing the injection rate,
The aggregation method according to claim 1, wherein the aggregation method is a step of determining an appropriate injection rate of the flocculant based on the plurality of numerical analysis values.
The aggregation method according to claim 11, wherein an injection rate at which a maximum value or a minimum value is obtained among the plurality of numerical analysis values is determined as the appropriate injection rate.
The average value of the injection rate at which the maximum value is obtained among the plurality of numerical analysis values and the injection rate at which the second largest value is obtained, or the injection rate at which the minimum value is obtained among the plurality of numerical analysis values The aggregation method according to claim 11, wherein an average value of the injection rate at which the second smallest value is obtained is determined as the appropriate injection rate.
The aggregation method according to claim 1, further comprising a correction injection rate determination step of determining a correction injection rate by multiplying an appropriate injection rate determined in the injection rate determination step by a correction coefficient.
A dilution step of diluting the stirred stock solution with a diluent;
The aggregation method according to claim 1, wherein the dilution step is performed between the stirring step and the optical measurement step.
A flocculant injection device for injecting the flocculant into a stock solution containing suspended solids;
A high-speed stirrer that stirs the stock solution into which the flocculant is injected by rotating a stirring blade at a rotation speed of 500 min −1 or more;
A supply device for supplying the stock solution to the high-speed stirrer;
An optical measurement device that irradiates the stirred stock solution with light to obtain optical measurement values;
A numerical analysis device for acquiring a numerical analysis value by numerically analyzing the optical measurement value;
And a control device for determining an appropriate injection rate of the flocculant based on the numerical analysis value.
The controller is
Based on the numerical analysis value, determine whether the injection rate of the flocculant is appropriate,
Operate one or both of the flocculant injection device and the supply device, the high-speed stirrer, the optical measurement device, and the numerical analysis device until an appropriate injection rate of the flocculant is determined. The injection of the flocculant into the stock solution, the stirring of the stock solution, the acquisition of the optical measurement value, and the acquisition of the numerical analysis value are repeated while changing the injection rate. The aggregating apparatus described.
The aggregating apparatus according to claim 16 or 17, wherein the optical measuring device measures the transmitted light intensity by irradiating the stirred stock solution with light.
The aggregating apparatus according to claim 16 or 17, wherein the optical measuring device measures the scattered light intensity by irradiating the stirred stock solution with light.
The aggregating apparatus according to claim 16 or 17, wherein the optical measuring device is both a measuring device for measuring transmitted light intensity and a measuring device for measuring scattered light intensity.
The aggregating apparatus according to any one of claims 16 to 20, wherein the numerical analysis device acquires a dispersion of the optical measurement value as the numerical analysis value.
The aggregating apparatus according to any one of claims 16 to 20, wherein the numerical analysis device acquires a peak area of the optical measurement value as the numerical analysis value.
The aggregating apparatus according to any one of claims 16 to 20, wherein the numerical analysis device acquires a standard deviation of the optical measurement value as the numerical analysis value.
The aggregating apparatus according to claim 16, wherein the numerical analysis device acquires a floc particle size of the suspended solid as the numerical analysis value.
The controller is
Either one or both of the flocculant injection device and the supply device, the high-speed stirrer, the optical measurement device, and the numerical analysis device are operated to inject the flocculant into the stock solution, the stock solution A plurality of numerical analysis values are obtained by repeating the agitation, acquisition of the optical measurement values, and acquisition of the numerical analysis values a plurality of times while changing the injection rate,
The aggregating apparatus according to claim 16, wherein an appropriate injection rate of the aggregating agent is determined based on the plurality of numerical analysis values.
26. The aggregating apparatus according to claim 25, wherein the control device determines an injection rate at which a maximum value or a minimum value is obtained among the plurality of numerical analysis values as the appropriate injection rate.
The control device has an average value of an injection rate at which a maximum value is obtained among the plurality of numerical analysis values and an injection rate at which a second largest value is obtained, or a minimum value among the plurality of numerical analysis values is 26. The aggregating apparatus according to claim 25, wherein an average value of the obtained injection rate and the injection rate at which the second smallest value is obtained is determined as the appropriate injection rate.
The aggregating apparatus according to claim 16, wherein the control device determines a correction injection rate by multiplying the determined appropriate injection rate by a correction coefficient.
The aggregation device according to claim 16, wherein the numerical analysis device is incorporated in the control device.
The aggregating apparatus according to claim 16, further comprising a diluent supply device for supplying a diluent to the stirred stock solution.