WO2020158565A1 - Water softening apparatus and water softening method - Google Patents

Water softening apparatus and water softening method Download PDF

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Publication number
WO2020158565A1
WO2020158565A1 PCT/JP2020/002301 JP2020002301W WO2020158565A1 WO 2020158565 A1 WO2020158565 A1 WO 2020158565A1 JP 2020002301 W JP2020002301 W JP 2020002301W WO 2020158565 A1 WO2020158565 A1 WO 2020158565A1
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Prior art keywords
water
treated
seed crystal
water softening
adjusted
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PCT/JP2020/002301
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French (fr)
Japanese (ja)
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義弘 坂口
綾音 竹久
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パナソニックＩｐマネジメント株式会社
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Publication of WO2020158565A1 publication Critical patent/WO2020158565A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D9/00—Crystallisation
    • B01D9/02—Crystallisation from solutions
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/34—Treatment of water, waste water, or sewage with mechanical oscillations
    • C02F1/36—Treatment of water, waste water, or sewage with mechanical oscillations ultrasonic vibrations
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/58—Treatment of water, waste water, or sewage by removing specified dissolved compounds
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F5/00—Softening water; Preventing scale; Adding scale preventatives or scale removers to water, e.g. adding sequestering agents

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  • the present invention relates to a water softening device and a water softening method.
  • a water softening device using an ion exchange resin is a structure for exchanging calcium ions and magnesium ions contained in tap water etc. for sodium ions to soften water, and has been widely used because of its simple structure.
  • Patent Document 1 a water softening device, when the water softening treatment is continued, the ion exchange capacity of the ion exchange resin gradually decreases. However, even if the ion exchange capacity is reduced, the ion exchange resin can be recovered by the regeneration treatment. Therefore, the water softening device using the ion exchange resin can be continuously used by regenerating the ion exchange resin.
  • Patent Document 2 Other known methods for softening water include electrolysis (see Patent Document 2) and an ion exchange membrane (see Patent Document 3).
  • An object of the present invention is to provide a water softening device and a water softening method that can realize softening of hard water with a simple configuration.
  • the water softening device is a treatment tank into which water to be treated, which is a target of water softening, is input, a pH adjusting unit for adjusting the pH of the water to be treated, and a hardness component in the water to be treated.
  • a seed crystal supply unit for supplying the seed crystal of No. 2 and an ultrasonic wave irradiation unit for irradiating the water to be treated with ultrasonic waves.
  • the water softening method comprises step A of adjusting the pH of the water to be treated to be softened, and supplying the seed crystal of the hardness component to the water to be treated to be water softened. And step B which is performed in no particular order, and after performing both step A and step B, step C of irradiating the water to be treated with ultrasonic waves is included.
  • FIG. 1 is a conceptual diagram showing an example of a water softening device according to this embodiment.
  • FIG. 2 is a conceptual diagram showing an example of the water softening device according to the present embodiment.
  • FIG. 3 is a graph showing the reduction rate of calcium ions with respect to the treatment time in Example 1 and Comparative Example 1.
  • FIG. 4 is a graph showing changes in pH with respect to treatment time in Example 2.
  • FIG. 5 is a graph showing the removal rate of calcium ions with respect to the treatment time in Example 2.
  • FIG. 6 is a graph showing changes in pH with respect to treatment time in Example 3.
  • FIG. 7 is a graph showing the removal rate of calcium ions with respect to the treatment time in Example 3.
  • FIG. 8 is a graph showing changes in pH with respect to treatment time in Examples 4 and 5.
  • FIG. 9 is a graph showing the removal rate of calcium ions with respect to the treatment time in Examples 4 and 5.
  • FIG. 10 is a graph showing changes in pH with respect to the concentration of calcium carbonate in Examples 6-1 to 9-4.
  • FIG. 11 is a graph showing the calcium ion removal rate with respect to the concentration of calcium carbonate in Examples 6-1 to 9-4.
  • the water softening device of the present embodiment is a treatment tank into which water to be treated which is a target of water softening is introduced, a pH adjusting unit for adjusting the pH of the water to be treated, and a seed crystal of a hardness component to the water to be treated.
  • the present invention is characterized in that it has a seed crystal supply unit for irradiating the water to be treated and an ultrasonic wave irradiation unit for irradiating the water to be treated with ultrasonic waves.
  • the pH of the water to be treated that has been put into the treatment tank is adjusted by the pH adjusting unit. Specifically, as described below, the pH of the water to be treated is adjusted to 7.8 or higher. Further, the seed crystal supply unit supplies the hardness component seed crystal (carbonate) into the water to be treated. Then, the ultrasonic wave is radiated by the ultrasonic wave irradiating unit to the water to be treated to which the pH is adjusted and the seed crystal is supplied. Then, with the seed crystal as a nucleus, a carbonate is crystallized from the carbonate ion in the water to be treated and the cation of the hardness component.
  • the pH adjusting unit Specifically, as described below, the pH of the water to be treated is adjusted to 7.8 or higher.
  • the seed crystal supply unit supplies the hardness component seed crystal (carbonate) into the water to be treated. Then, the ultrasonic wave is radiated by the ultrasonic wave irradiating unit to the water to be treated to which the pH is adjusted and
  • the ultrasonic irradiation increases the ion concentration in the ultrasonic wave in the dense portion of the ultrasonic wave in the water to be treated, and promotes the crystallization of the carbonate with the seed crystal as the nucleus. From the above, in the water to be treated, the hardness component ions are reduced by crystallization, and the water is softened.
  • FIG. 1 is a conceptual diagram showing an example of the water softening device of this embodiment.
  • the water softening device 10 shown in FIG. 1 includes a treatment tank 12, a pH adjusting unit 16, a seed crystal supplying unit 18, and an ultrasonic wave irradiating unit 20.
  • the treatment tank 12 is filled with the water 14 to be treated which is to be softened.
  • the pH adjusting unit 16 adjusts the pH of the water to be treated 14 to a desired value, and the seed crystal supplying unit 18 supplies the seed crystal of the hardness component to the water to be treated 14.
  • the ultrasonic wave irradiator 20 irradiates the water to be treated with ultrasonic waves through the vibrator 22.
  • the water softening device 10 further includes a pH detector 24 that detects the pH of the water 14 to be treated, and a chiller 27 that cools the water 14 to be treated.
  • the treatment tank 12 may have any shape as long as it can contain the water 14 to be treated and has an opening for injecting the water 14 to be treated.
  • the material of the processing tank 12 can be appropriately selected from those used in known water softening devices.
  • the pH adjuster 16 adjusts the pH of the water 14 to be treated.
  • the water to be treated 14 permanently contains a carbonic acid component originating from carbon dioxide in the atmosphere, and the carbonic acid component in the water to be treated 14 is a carbonate ion (CO 3 2 ⁇ ) or a hydrogen carbonate ion (HCO). 3 -) exists as.
  • the carbonate ion and the hydrogen carbonate ion exist in the water 14 to be treated in an equilibrium state in which the abundance ratio changes depending on the pH. The higher the pH, the higher the carbonate ion abundance ratio.
  • the pH adjuster 16 adjusts the pH of the water 14 to be treated to a high value to increase the carbonate ion abundance ratio and grow carbonate crystals.
  • the means for adjusting the pH by the pH adjusting unit 16 is not particularly limited.
  • the pH of the water to be treated 14 adjusted by the pH adjusting unit 16 is preferably 7.8 or higher, and more preferably 9.0 or higher.
  • pH is a value in 25 degreeC.
  • the buffering agent exhibits a buffering ability at a pH of 7.8 or higher.
  • the seed crystal supply unit 18 supplies a seed crystal of hardness component.
  • the hardness component refers to calcium and magnesium
  • the seed crystal used is one that grows a crystal of a calcium salt or a magnesium salt with itself as a nucleus.
  • Specific examples of the seed crystal include calcium carbonate as the seed crystal for the calcium component.
  • Examples of the seed crystal for the magnesium component include magnesium carbonate.
  • the seed crystal supply unit 18 may mechanically supply the seed crystal by a driving means such as a motor, or by opening or closing a container containing the seed crystal mechanically or artificially. A means for supplying seed crystals from the container may be used.
  • the average grain size of the seed crystals supplied by the seed crystal supply unit 18 is preferably less than 2 ⁇ m. If the seed crystal has an average particle size of less than 2 ⁇ m, crystallization can be promoted regardless of its concentration.
  • the average grain size of the seed crystal is more preferably 1 ⁇ m or less, further preferably 0.15 ⁇ m or less.
  • the lower limit of the average particle size of the seed crystal is usually 0.1 ⁇ m.
  • the grain size of the seed crystal supplied by the seed crystal supply unit may be 2 ⁇ m or more. However, in the case of a seed crystal having an average particle size of 2 ⁇ m or more, the degree of progress of crystallization depends on the concentration.
  • the “average particle size” is a volume-based average particle size measured by a laser diffraction/scattering method, and more specifically, obtained by a particle size distribution measurement by a laser diffraction/scattering method. It is the median diameter obtained based on the particle size distribution.
  • a vibrator 22 is connected to the ultrasonic wave irradiation unit 20, and ultrasonic waves are emitted via the vibrator 22.
  • the frequency of the ultrasonic waves to be applied is not particularly limited, but may be 20 kHz or higher and is preferably 1 MHz or higher.
  • the output of ultrasonic waves is not particularly limited and can be set within a generally used range.
  • the water softening device 10 further includes a pH detection unit 24 that detects the pH of the water to be treated.
  • a pH sensor 26 is connected to the pH detection unit 24, the pH of the water to be treated is measured by the pH sensor 26, and the pH detection unit 24 detects the value.
  • the pH detection unit 24 and the pH sensor 26 known ones can be applied. In addition, in this embodiment, the pH detection unit is not always necessary.
  • the water softening device 10 further has a temperature adjusting mechanism (not shown) that adjusts the temperature of the water to be treated. That is, crystallization is more likely to proceed as the temperature increases, so it is preferable to set the temperature higher by the temperature adjusting mechanism.
  • the temperature adjusting mechanism is not particularly limited as long as it can adjust the temperature of the water to be treated.
  • the water softening device 10 has a chiller 27 for cooling the water 14 to be treated. Since the water to be treated 14 generates heat by irradiation with ultrasonic waves, it is preferable to circulate and cool the chiller 27.
  • FIG. 2 is a conceptual diagram showing a water softening device in the case where the water to be treated to be water softened is running water.
  • the water softening device 11 shown in FIG. 2 includes a treatment tank 13, a pH adjusting unit 16, a seed crystal supplying unit 18, and an ultrasonic wave irradiating unit 20.
  • the treatment tank 13 is provided with a flow passage 28 for allowing the treated water 14 as running water to flow into the treatment tank 13, and a passage 30 for discharging the treated water 14 that has been treated.
  • the processing tank 13 It flows into the processing tank 13 via the and is discharged via the flow path 30.
  • the pH adjusting unit 16, the seed crystal supplying unit 18, the ultrasonic wave irradiating unit 20, and the pH detecting unit 24 are the same as those in the water softening device 10 shown in FIG. Is omitted.
  • the treatment tank 13 which is a difference from the water softening device 10 and the water to be treated which is running water will be explained.
  • the processing tank 13 does not have an opening like the processing tank 12 shown in FIG. 1, and does not communicate with the outside except for the channels 28 and 30.
  • a tap water supply pipe is connected, and in that case, tap water is the water to be treated.
  • the pH of the water to be treated 14 flowing into the treatment tank 13 is adjusted by the pH adjusting unit 16, and the seed crystal supplying unit 18 supplies the seed crystal.
  • the water to be treated 14 is irradiated with ultrasonic waves by the ultrasonic wave irradiation unit 20, and the hardness component is crystallized to be softened.
  • the pH detection unit 24 can be set to detect the pH value and adjust the pH when the pH value is below a certain value. Further, it can be set so as to adjust the pH according to the flow rate.
  • the means for removing the seed crystal is not particularly limited, and known means can be applied.
  • means for passing the water to be treated through a filter through which the seed crystal does not pass can be used.
  • the water softening method of the present embodiment includes a step A of adjusting the pH of the water to be treated which is the object of water softening, and a step B of supplying a seed crystal of a hardness component to the water to be treated which is the object of water softening, In any order.
  • the method is characterized by including step C of irradiating the water to be treated with ultrasonic waves after performing both step A and step B.
  • step A the pH of the water to be treated to be water softened is adjusted (step A), and a seed crystal of hardness component is supplied (step B). That is, as described above, the pH of the water to be treated is adjusted to 7.8 or higher. Further, a seed crystal (carbonate) of the hardness component is supplied to the water to be treated.
  • step C ultrasonic waves are radiated to the water to be treated to which the pH has been adjusted and the seed crystals have been supplied.
  • step C ultrasonic waves are radiated to the water to be treated to which the pH has been adjusted and the seed crystals have been supplied.
  • step C the ion concentration increases in the dense part of the ultrasonic waves, and the carbonate crystallizes with the seed crystal as the nucleus. That is, the ions of the hardness component are reduced in the water to be treated, and the water is softened. Finally, the crystallized seed crystals are removed.
  • the water softening method of the present embodiment can be executed by, for example, the water softening device of the present embodiment described above, but is not limited to the water softening device.
  • the instruments there is a treatment tank containing the water to be treated, and a device for irradiating the water to be treated in the treatment tank with ultrasonic waves.
  • the water softening method of the embodiment can be executed. Each step will be described below.
  • step A the pH of the water to be treated which is to be softened is adjusted. As described above, the pH is adjusted so that the ratio of carbonate ions in the water to be treated becomes large. The higher the pH, the higher the ratio of carbonate ions, and therefore the pH of the water to be treated is preferably adjusted to 7.8 or higher, more preferably 9.0 or higher in order to further promote crystallization. ..
  • the pH will decrease with its consumption. Therefore, when the pH is lowered, the ratio of carbonate ions does not increase unless the alkali agent is replenished, and crystallization tends not to proceed sufficiently. Therefore, it is preferable to replenish the alkaline agent every predetermined time to adjust the pH.
  • the pH can be detected and an alkaline agent can be supplied to adjust the pH when the pH falls below a certain level.
  • step A it is preferable to supply a buffer to the water to be treated.
  • a buffering agent By supplying a buffering agent to the water to be treated, it is possible to mitigate fluctuations in the pH of the water to be treated. That is, it is possible to suppress the decrease in pH when the alkaline agent is used as described above. Specific examples of the buffering agent have been described above, and thus will be omitted here.
  • step B a seed crystal of hardness component (calcium component or magnesium component) is supplied to the water to be treated which is to be softened.
  • seed crystals for the calcium component include calcium carbonate.
  • seed crystal for the magnesium component include magnesium carbonate.
  • step B it is preferable to supply a seed crystal having an average particle size of less than 2 ⁇ m.
  • a seed crystal having an average particle size of less than 2 ⁇ m is supplied, sufficient crystallization can be achieved without depending on its concentration.
  • the concentration of the seed crystal in the water to be treated is preferably 100 ppm or more and less than 500 ppm, more preferably 300 ppm or more and less than 500 ppm.
  • the concentration of the seed crystal in the water to be treated is preferably 500 ppm or more, more preferably 1000 ppm or more.
  • Step A and Step B are in random order, and it does not matter which of Step A and Step B is executed first.
  • step C the water to be treated is irradiated with ultrasonic waves after execution of both step A and step B.
  • the ultrasonic wave to be applied may have a frequency of 20 kHz or higher, preferably 1 MHz or higher.
  • the irradiation time of ultrasonic waves can be set according to the hardness of the water to be treated. That is, when the hardness of the water to be treated is high, the irradiation time can be extended, and when the hardness is low, the irradiation time can be shortened. Further, in the case of running water, it can be appropriately set according to the flow velocity.
  • the temperature of the water to be treated can be adjusted to less than 30°C. That is, the water to be treated can be kept at room temperature or lower. If the temperature is lower than room temperature, crystallization usually does not proceed, or the progress speed tends to be slow even if it progresses. Crystallization is promoted also below.
  • the lower limit of the temperature of the water to be treated is 0°C.
  • the temperature of the water to be treated can be adjusted to 30°C or higher. If the temperature of the water to be treated is high, crystallization is likely to proceed. Therefore, it is preferable to set the temperature to 30° C. or higher by heating or the like.
  • ⁇ Continuing Step C will reduce the consumption of alkaline agents and the pH of the water to be treated. Therefore, when the pH of the water to be treated decreases (for example, less than 7.8), it is preferable to add an alkaline agent.
  • the method for removing the seed crystal is not particularly limited, and a known method can be applied. For example, a method of passing treated water through a filter through which seed crystals do not pass can be used.
  • the water softening device and the water softening method of this embodiment described above can be applied to a place-of-use installed water purifier (POU) and a building entrance installed water purifier (POE).
  • POU place-of-use installed water purifier
  • POE building entrance installed water purifier
  • Example 1 A 200 ml beaker was filled with Evian (manufactured by Danone Japan Co., Ltd., water temperature: 20° C.) as water to be treated, and sodium hydroxide was added to adjust the pH to 7.8. Next, calcium carbonate (average particle size: 0.15 ⁇ m) was added as a seed crystal so that the concentration was 1 ppm. After that, ultrasonic waves were applied under the following conditions to soften the water. A chiller was connected to the beaker, and circulation cooling was performed to maintain the temperature of 20°C. (Ultrasonic conditions) Ultrasonic device: SONIFIER450 (made by Rika Ikeda) Output: 20W Frequency: 25kHz Duty cycle: 50
  • Example 1 Water softening was performed in the same manner as in Example 1 except that the pH was not adjusted, and the calcium ion reduction rate was calculated in the same manner as in Example 1. A graph showing the calculation result is shown in FIG.
  • Example 2 In Example 1, the initial pH was set to 8.1, and then the same treatment was performed for 60 minutes. A graph showing the change in pH with the treatment time is shown in FIG. Further, a graph showing the removal rate of calcium ions with respect to the treatment time is shown in FIG.
  • Example 3 In Example 2, water was softened for 1 hour while replenishing sodium hydroxide every 5 minutes to adjust the pH. The change in pH with time is shown in the graph of FIG. The graph of FIG. 7 shows the removal rate of calcium ions with respect to the treatment time.
  • Example 4 A 200 ml beaker was filled with Evian (manufactured by Danone Japan Co., Ltd., water temperature: 20° C.) as water to be treated, and sodium hydroxide was added to adjust the pH to 8.1. Next, calcium carbonate (average particle diameter: 0.15 ⁇ m) was added as a seed crystal so that the concentration was 100 ppm. After that, ultrasonic waves were applied under the following conditions to soften the water. A chiller was connected to the beaker, and circulation cooling was performed to maintain the temperature of 20°C. (Ultrasonic conditions) Ultrasonic device: Ultrasonic atomization unit (IM1-24/LW, manufactured by Seikou Giken Co., Ltd.) Output: 17W Frequency: 1600kHz Duty cycle: 100
  • Example 5 Water softening was performed in the same manner as in Example 4 except that Tris buffer (0.1 M) was used instead of sodium hydroxide and the initial pH was adjusted to about 9.
  • FIG. 8 shows a graph showing changes in pH with respect to treatment time in Examples 4 and 5. Further, FIG. 9 shows a graph showing the removal rate of calcium ions with respect to the treatment time.
  • Example 6-1 A 200 ml beaker was filled with Evian (manufactured by Danone Japan Co., Ltd., water temperature: 20° C.) as water to be treated, and a Tris buffer (0.1 M) was added. Next, calcium carbonate was added as a seed crystal (average particle size: 0.15 ⁇ m) so that the concentration would be 10 ppm. After that, ultrasonic waves were applied under the following conditions to soften the water. (Ultrasonic conditions) Ultrasonic device: Ultrasonic atomization unit (IM1-24/LW, manufactured by Seikou Giken Co., Ltd.) Output: 17W Frequency: 1600kHz Duty cycle: 100 Ultrasonic irradiation time: 1 minute
  • Example 6-2 Water softening was performed in the same manner as in Example 6-1, except that calcium carbonate was added so as to have a concentration of 100 ppm.
  • Example 6-3 Water softening was performed in the same manner as in Example 6-1, except that calcium carbonate was added so as to have a concentration of 500 ppm.
  • Example 6-4 Water softening was performed in the same manner as in Example 6-1 except that calcium carbonate was added so as to have a concentration of 1000 ppm.
  • Example 7-1 Water softening was performed in the same manner as in Example 6-1 except that calcium carbonate having an average particle size of 1.2 ⁇ m was used as a seed crystal.
  • Example 7-2 Water softening was performed in the same manner as in Example 7-1, except that calcium carbonate was added so as to have a concentration of 100 ppm.
  • Example 7-3 Water softening was performed in the same manner as in Example 7-1 except that calcium carbonate was added so that the concentration would be 500 ppm.
  • Example 7-4 Water softening was performed in the same manner as in Example 7-1 except that calcium carbonate was added so that the concentration became 1000 ppm.
  • Example 8-1 Water softening was performed in the same manner as in Example 6-1 except that calcium carbonate having an average particle size of 4.0 ⁇ m was used as a seed crystal.
  • Example 8-2 Water softening was performed in the same manner as in Example 8-1, except that calcium carbonate was added so that the concentration became 100 ppm.
  • Example 8-3 Water softening was performed in the same manner as in Example 8-1, except that calcium carbonate was added so that the concentration was 500 ppm.
  • Example 8-4 Water softening was performed in the same manner as in Example 8-1 except that calcium carbonate was added so as to have a concentration of 1000 ppm.
  • Example 9-1 Water softening was performed in the same manner as in Example 6-1 except that calcium carbonate having an average particle size of 8.0 ⁇ m was used as a seed crystal.
  • Example 9-2 Water softening was performed in the same manner as in Example 9-1 except that calcium carbonate was added so as to have a concentration of 100 ppm.
  • Example 9-3 Water softening was performed in the same manner as in Example 9-1 except that calcium carbonate was added so as to have a concentration of 500 ppm.
  • Example 9-4 Water softening was performed in the same manner as in Example 9-1 except that calcium carbonate was added so as to have a concentration of 1000 ppm.
  • FIG. 10 shows a graph showing changes in pH with respect to the concentration of calcium carbonate in Examples 6-1 to 9-4.
  • FIG. 11 shows a graph showing the removal rate of calcium ions with respect to the concentration of calcium carbonate.

Abstract

A water softening apparatus equipped with a treatment tank in which water of interest, which is water to be softened, is introduced, a pH adjustment section for adjusting the pH value of the water of interest, a seed crystal feeding section for feeding a seed crystal of a hardness component to the water of interest, and an ultrasonic wave irradiation section for irradiating the water of interest with ultrasonic waves; and a water softening method comprising step A of adjusting the pH value of water of interest which is water to be softened and step B of feeding a seed crystal of a hardness component to the water of interest which is water to be softened, wherein the step A and step B are carried out in a random order and step C of irradiating the water of interest with ultrasonic waves is further included subsequent to the completion of both of step A and step B.

Description

軟水化装置及び軟水化方法Water softening device and water softening method
　本発明は、軟水化装置及び軟水化方法に関する。 The present invention relates to a water softening device and a water softening method.
　硬水を軟水化するための軟水化装置における軟水化手法としては、種々の手法が提案されている。中でも、イオン交換樹脂を用いた軟水化装置は、水道水等に含まれるカルシウムイオン及びマグネシウムイオンを、ナトリウムイオンに交換して軟水化する構成であり、構成が簡単であることから多用されてきた（特許文献１参照）。そのような軟水化装置は、軟水化の処理を継続すると、イオン交換樹脂のイオン交換能力が徐々に低下する。しかし、イオン交換能力が低下したとしても、イオン交換樹脂は再生処理によって回復することができる。そのため、イオン交換樹脂を用いた軟水化装置は、イオン交換樹脂の再生処理により継続して使用することができる。 Various methods have been proposed as a water softening method in a water softening device for softening hard water. Among them, a water softening device using an ion exchange resin is a structure for exchanging calcium ions and magnesium ions contained in tap water etc. for sodium ions to soften water, and has been widely used because of its simple structure. (See Patent Document 1). In such a water softening device, when the water softening treatment is continued, the ion exchange capacity of the ion exchange resin gradually decreases. However, even if the ion exchange capacity is reduced, the ion exchange resin can be recovered by the regeneration treatment. Therefore, the water softening device using the ion exchange resin can be continuously used by regenerating the ion exchange resin.
　他の軟水化手法としては、電気分解によるもの（特許文献２参照）、イオン交換膜を用いたもの（特許文献３参照）が知られている。 Other known methods for softening water include electrolysis (see Patent Document 2) and an ion exchange membrane (see Patent Document 3).
特開２０１４－１００６３３号公報Japanese Patent Laid-Open No. 2014-100633 特開平５－２８５４８１号公報Japanese Patent Laid-Open No. 5-285481 特開２００３－０５３３３９号公報JP, 2003-053339, A
　しかしながら、イオン交換樹脂を用いた軟水化装置においては、イオン交換樹脂の再生処理の際に多量の食塩を用いるため環境問題の原因となっており、代替技術が求められている。その上、イオン交換樹脂の再生処理による回復には限界があり、所定期間を超えて使用すると回復が困難となる。すなわち、イオン交換樹脂には寿命があり、寿命期間を超えて使用することはできない。また、電気分解によるものは電極の析出物を除去するなど、メンテナンスが必要である。さらに、イオン交換膜を用いたものは、イオン交換膜を被処理水が通過できるように、被処理水を高圧にする必要がある。 However, in a water softening device using an ion exchange resin, a large amount of salt is used during the regeneration treatment of the ion exchange resin, which causes an environmental problem, and an alternative technique is required. In addition, there is a limit to the recovery of the ion exchange resin by the regenerating process, and the recovery becomes difficult if the ion exchange resin is used for a predetermined period or longer. That is, the ion exchange resin has a life and cannot be used beyond the life period. In addition, electrolysis requires maintenance such as removal of electrode deposits. Further, in the case of using the ion exchange membrane, the water to be treated needs to have a high pressure so that the water to be treated can pass through the ion exchange membrane.
　以上の通り、従来の軟水化装置の構成では、再生処理などの煩わしいメンテナンスが必要であったり、水圧を高圧にするための機構が必要であったり、簡単な構成で軟水化を図ることが困難であった。 As described above, in the configuration of the conventional water softening device, it is difficult to achieve water softening with a simple configuration, because complicated maintenance such as regeneration processing is required, a mechanism for increasing the water pressure is required. Met.
　本発明は、このような従来技術の有する課題に鑑みてなされたものである。そして、本発明の目的は、硬水の軟水化を簡単な構成で実現することができる軟水化装置及び軟水化方法を提供することにある。 The present invention has been made in view of such problems of the conventional technology. An object of the present invention is to provide a water softening device and a water softening method that can realize softening of hard water with a simple configuration.
　本発明の第１の態様に係る軟水化装置は、軟水化の対象となる被処理水が投入される処理槽と、被処理水のｐＨを調整するｐＨ調整部と、被処理水に硬度成分の種結晶を供給する種結晶供給部と、被処理水に超音波を照射する超音波照射部と、を有する。 The water softening device according to the first aspect of the present invention is a treatment tank into which water to be treated, which is a target of water softening, is input, a pH adjusting unit for adjusting the pH of the water to be treated, and a hardness component in the water to be treated. A seed crystal supply unit for supplying the seed crystal of No. 2 and an ultrasonic wave irradiation unit for irradiating the water to be treated with ultrasonic waves.
　本発明の第２の態様に係る軟水化方法は、軟水化の対象となる被処理水のｐＨを調整するステップＡと、軟水化の対象となる被処理水に、硬度成分の種結晶を供給するステップＢと、を順不同で含み、ステップＡ及びステップＢの双方の実行後に、前記被処理水に超音波を照射するステップＣを含む。 The water softening method according to the second aspect of the present invention comprises step A of adjusting the pH of the water to be treated to be softened, and supplying the seed crystal of the hardness component to the water to be treated to be water softened. And step B which is performed in no particular order, and after performing both step A and step B, step C of irradiating the water to be treated with ultrasonic waves is included.
図１は、本実施形態に係る軟水化装置の一例を示す概念図である。FIG. 1 is a conceptual diagram showing an example of a water softening device according to this embodiment. 図２は、本実施形態に係る軟水化装置の一例を示す概念図である。FIG. 2 is a conceptual diagram showing an example of the water softening device according to the present embodiment. 図３は、実施例１及び比較例１における、処理時間に対するカルシウムイオン減少率を示すグラフである。FIG. 3 is a graph showing the reduction rate of calcium ions with respect to the treatment time in Example 1 and Comparative Example 1. 図４は、実施例２における、処理時間に対するｐＨの変化を示すグラフである。FIG. 4 is a graph showing changes in pH with respect to treatment time in Example 2. 図５は、実施例２における、処理時間に対するカルシウムイオンの除去率を示すグラフである。FIG. 5 is a graph showing the removal rate of calcium ions with respect to the treatment time in Example 2. 図６は、実施例３における、処理時間に対するｐＨの変化を示すグラフである。FIG. 6 is a graph showing changes in pH with respect to treatment time in Example 3. 図７は、実施例３における、処理時間に対するカルシウムイオンの除去率を示すグラフである。FIG. 7 is a graph showing the removal rate of calcium ions with respect to the treatment time in Example 3. 図８は、実施例４及び５における、処理時間に対するｐＨの変化を示すグラフである。FIG. 8 is a graph showing changes in pH with respect to treatment time in Examples 4 and 5. 図９は、実施例４及び５における、処理時間に対するカルシウムイオンの除去率を示すグラフである。FIG. 9 is a graph showing the removal rate of calcium ions with respect to the treatment time in Examples 4 and 5. 図１０は、実施例６－１～９－４における、炭酸カルシウムの濃度に対するｐＨの変化を示すグラフである。FIG. 10 is a graph showing changes in pH with respect to the concentration of calcium carbonate in Examples 6-1 to 9-4. 図１１は、実施例６－１～９－４における、炭酸カルシウムの濃度に対するカルシウムイオンの除去率を示すグラフである。FIG. 11 is a graph showing the calcium ion removal rate with respect to the concentration of calcium carbonate in Examples 6-1 to 9-4.
＜軟水化装置＞
　本実施形態の軟水化装置は、軟水化の対象となる被処理水が投入される処理槽と、被処理水のｐＨを調整するｐＨ調整部と、被処理水に硬度成分の種結晶を供給する種結晶供給部と、被処理水に超音波を照射する超音波照射部と、を有することを特徴としている。 <Water softener>
The water softening device of the present embodiment is a treatment tank into which water to be treated which is a target of water softening is introduced, a pH adjusting unit for adjusting the pH of the water to be treated, and a seed crystal of a hardness component to the water to be treated. The present invention is characterized in that it has a seed crystal supply unit for irradiating the water to be treated and an ultrasonic wave irradiation unit for irradiating the water to be treated with ultrasonic waves.
　本実施形態の軟水化装置においては、処理槽に投入された被処理水は、ｐＨ調整部によりｐＨが調整される。具体的には、後述するように、被処理水のｐＨが７．８以上に調整される。また、種結晶供給部により、被処理水中に硬度成分の種結晶（炭酸塩）が供給される。そして、ｐＨが調整され、種結晶が供給された被処理水に対し、超音波照射部により超音波を照射する。すると、種結晶を核として、被処理水中の炭酸イオンと、硬度成分の陽イオンとから炭酸塩が晶析する。このとき、超音波照射により、被処理水中において超音波の密部でイオン濃度が高くなり、種結晶を核として炭酸塩の晶析が促進される。以上より、被処理水中において、硬度成分のイオンが晶析により減少し、軟水化される。 In the water softener of the present embodiment, the pH of the water to be treated that has been put into the treatment tank is adjusted by the pH adjusting unit. Specifically, as described below, the pH of the water to be treated is adjusted to 7.8 or higher. Further, the seed crystal supply unit supplies the hardness component seed crystal (carbonate) into the water to be treated. Then, the ultrasonic wave is radiated by the ultrasonic wave irradiating unit to the water to be treated to which the pH is adjusted and the seed crystal is supplied. Then, with the seed crystal as a nucleus, a carbonate is crystallized from the carbonate ion in the water to be treated and the cation of the hardness component. At this time, the ultrasonic irradiation increases the ion concentration in the ultrasonic wave in the dense portion of the ultrasonic wave in the water to be treated, and promotes the crystallization of the carbonate with the seed crystal as the nucleus. From the above, in the water to be treated, the hardness component ions are reduced by crystallization, and the water is softened.
　図１は、本実施形態の軟水化装置の一例を示す概念図である。図１に示す軟水化装置１０は、処理槽１２と、ｐＨ調整部１６と、種結晶供給部１８と、超音波照射部２０とを有する。処理槽１２には、軟水化の対象となる被処理水１４が満たされる。ｐＨ調整部１６は、被処理水１４のｐＨが所望の値となるように調整し、種結晶供給部１８は、被処理水１４に硬度成分の種結晶を供給する。超音波照射部２０は、振動子２２を介して被処理水に超音波を照射する。軟水化装置１０は、さらに、被処理水１４のｐＨを検出するｐＨ検出部２４と、被処理水１４を冷却するチラー２７とを有する。 FIG. 1 is a conceptual diagram showing an example of the water softening device of this embodiment. The water softening device 10 shown in FIG. 1 includes a treatment tank 12, a pH adjusting unit 16, a seed crystal supplying unit 18, and an ultrasonic wave irradiating unit 20. The treatment tank 12 is filled with the water 14 to be treated which is to be softened. The pH adjusting unit 16 adjusts the pH of the water to be treated 14 to a desired value, and the seed crystal supplying unit 18 supplies the seed crystal of the hardness component to the water to be treated 14. The ultrasonic wave irradiator 20 irradiates the water to be treated with ultrasonic waves through the vibrator 22. The water softening device 10 further includes a pH detector 24 that detects the pH of the water 14 to be treated, and a chiller 27 that cools the water 14 to be treated.
　処理槽１２は、被処理水１４を収容することができ、被処理水１４を注入するための開口部を有しているものであれば形状は問わない。処理槽１２の材質としても、公知の軟水化装置において使用されているものから適宜選定することができる。 The treatment tank 12 may have any shape as long as it can contain the water 14 to be treated and has an opening for injecting the water 14 to be treated. The material of the processing tank 12 can be appropriately selected from those used in known water softening devices.
　ｐＨ調整部１６は、被処理水１４のｐＨを調整する。ここで、被処理水１４には大気中の二酸化炭素等に起因する炭酸成分を常在的に含み、炭酸成分は被処理水１４中で炭酸イオン（ＣＯ３ ２－）又は炭酸水素イオン（ＨＣＯ３ －）として存在する。炭酸イオン及び炭酸水素イオンは、被処理水１４中において、ｐＨによって存在比率が変化する平衡状態で存在している。そして、ｐＨが大きくなるほど炭酸イオンの存在比率が大きくなる。本実施形態においては、ｐＨ調整部１６により被処理水１４のｐＨが大きくなるように調整して炭酸イオンの存在比率を大きくし、炭酸塩の結晶を成長させる。 The pH adjuster 16 adjusts the pH of the water 14 to be treated. Here, the water to be treated 14 permanently contains a carbonic acid component originating from carbon dioxide in the atmosphere, and the carbonic acid component in the water to be treated 14 is a carbonate ion (CO 3 2− ) or a hydrogen carbonate ion (HCO). 3 -) exists as. The carbonate ion and the hydrogen carbonate ion exist in the water 14 to be treated in an equilibrium state in which the abundance ratio changes depending on the pH. The higher the pH, the higher the carbonate ion abundance ratio. In the present embodiment, the pH adjuster 16 adjusts the pH of the water 14 to be treated to a high value to increase the carbonate ion abundance ratio and grow carbonate crystals.
　ｐＨ調整部１６によるｐＨを調整する手段としては特に限定はない。例えば、水酸化ナトリウム、水酸化カリウム等のアルカリ剤、又はトリス緩衝剤、ＮＨ３－ＮＨ４Ｃｌ系のｐＨ１０の緩衝液等の緩衝剤を供給する手段でもよいし、電気分解によりｐＨを調整する手段でもよい。 The means for adjusting the pH by the pH adjusting unit 16 is not particularly limited. For example, a means for supplying an alkali agent such as sodium hydroxide or potassium hydroxide, or a buffer agent such as Tris buffer, NH 3 —NH 4 Cl-based buffer solution having a pH of 10 or the like, or adjusting the pH by electrolysis. Means may be used.
　ｐＨ調整部１６によって調整される被処理水１４のｐＨは７．８以上であることが好ましく、９．０以上であることがより好ましい。上述の通り、被処理水１４のｐＨが大きくなるほど炭酸イオンの存在比率が大きくなり、晶析が進行しやすくなる。すなわち、晶析を促進するには被処理水１４のｐＨは７．８以上が好ましく、９．０以上がより好ましい。なお、本明細書において、ｐＨは２５℃における値である。 The pH of the water to be treated 14 adjusted by the pH adjusting unit 16 is preferably 7.8 or higher, and more preferably 9.0 or higher. As described above, the higher the pH of the water to be treated 14 is, the higher the carbonate ion abundance ratio is, and the more easily the crystallization proceeds. That is, in order to promote crystallization, the pH of the water to be treated 14 is preferably 7.8 or higher, more preferably 9.0 or higher. In addition, in this specification, pH is a value in 25 degreeC.
　一方、ｐＨの調整にアルカリ剤を用いると、その消費に伴いｐＨが低下する。そのため、ｐＨが低下した場合、アルカリ剤を補充しないと炭酸イオンの比率が大きくならず、晶析が十分に進行しなくなる傾向にある。しかし、緩衝剤を添加するとｐＨの変動を抑えることができ、炭酸イオンの比率が安定し、安定した晶析を行うことができる。なお、緩衝剤としては、晶析を促進する観点から、ｐＨが７．８以上において緩衝能を発揮するものが好ましい。 On the other hand, if an alkaline agent is used to adjust the pH, the pH will drop as it is consumed. Therefore, when the pH is lowered, the ratio of carbonate ions does not increase unless the alkali agent is replenished, and crystallization tends not to proceed sufficiently. However, when a buffering agent is added, fluctuations in pH can be suppressed, the ratio of carbonate ions is stabilized, and stable crystallization can be performed. From the viewpoint of promoting crystallization, it is preferable that the buffering agent exhibits a buffering ability at a pH of 7.8 or higher.
　種結晶供給部１８は、硬度成分の種結晶を供給する。本実施形態において、硬度成分とは、カルシウム及びマグネシウムを指し、種結晶は、それ自身を核としてカルシウム塩又はマグネシウム塩の結晶を成長させるものが用いられる。種結晶の具体例としては、カルシウム成分に対する種結晶としては、炭酸カルシウムが挙げられる。マグネシウム成分に対する種結晶としては、炭酸マグネシウムが挙げられる。 The seed crystal supply unit 18 supplies a seed crystal of hardness component. In the present embodiment, the hardness component refers to calcium and magnesium, and the seed crystal used is one that grows a crystal of a calcium salt or a magnesium salt with itself as a nucleus. Specific examples of the seed crystal include calcium carbonate as the seed crystal for the calcium component. Examples of the seed crystal for the magnesium component include magnesium carbonate.
　種結晶供給部１８は、モーター等の駆動手段により機械的に種結晶を供給するものであってもよいし、種結晶が収容された容器に対し開閉機構等を機械的又は人為的な操作により当該容器から種結晶が供給するような手段であってもよい。 The seed crystal supply unit 18 may mechanically supply the seed crystal by a driving means such as a motor, or by opening or closing a container containing the seed crystal mechanically or artificially. A means for supplying seed crystals from the container may be used.
　種結晶供給部１８により供給される種結晶の平均粒径は２μｍ未満であることが好ましい。平均粒径が２μｍ未満の種結晶であれば、その濃度によらず晶析を促進することができる。当該種結晶の平均粒径は１μｍ以下であることがより好ましく、０．１５μｍ以下であることがさらに好ましい。当該種結晶の平均粒径の下限は、通常０．１μｍである。
　一方、種結晶供給部により供給される種結晶の粒径は２μｍ以上であってもよい。ただし、平均粒径が２μｍ以上の種結晶の場合、晶析の進行の度合は濃度に依存する。そのため、平均粒径が２μｍ以上の種結晶の場合、当該種結晶の濃度を高くすることが好ましい。当該濃度の具体的範囲については後述する。
　なお、本明細書において、「平均粒径」は、レーザー回折・散乱法により測定される体積基準の平均粒径であり、より具体的には、レーザー回折・散乱法による粒度分布測定で得られた粒度分布に基づいて得られるメジアン径である。 The average grain size of the seed crystals supplied by the seed crystal supply unit 18 is preferably less than 2 μm. If the seed crystal has an average particle size of less than 2 μm, crystallization can be promoted regardless of its concentration. The average grain size of the seed crystal is more preferably 1 μm or less, further preferably 0.15 μm or less. The lower limit of the average particle size of the seed crystal is usually 0.1 μm.
On the other hand, the grain size of the seed crystal supplied by the seed crystal supply unit may be 2 μm or more. However, in the case of a seed crystal having an average particle size of 2 μm or more, the degree of progress of crystallization depends on the concentration. Therefore, in the case of a seed crystal having an average particle size of 2 μm or more, it is preferable to increase the concentration of the seed crystal. The specific range of the concentration will be described later.
In the present specification, the “average particle size” is a volume-based average particle size measured by a laser diffraction/scattering method, and more specifically, obtained by a particle size distribution measurement by a laser diffraction/scattering method. It is the median diameter obtained based on the particle size distribution.
　超音波照射部２０は、振動子２２が接続され、振動子２２を介して超音波が照射される。照射する超音波の周波数は特に制限はないが、２０ｋＨｚ以上であればよく、１ＭＨｚ以上が好ましい。超音波の出力は特に制限はなく、一般に使用される範囲で設定することができる。 A vibrator 22 is connected to the ultrasonic wave irradiation unit 20, and ultrasonic waves are emitted via the vibrator 22. The frequency of the ultrasonic waves to be applied is not particularly limited, but may be 20 kHz or higher and is preferably 1 MHz or higher. The output of ultrasonic waves is not particularly limited and can be set within a generally used range.
　軟水化装置１０には、さらに、被処理水のｐＨを検出するｐＨ検出部２４を有する。ｐＨ検出部２４にはｐＨセンサー２６が接続され、ｐＨセンサー２６により被処理水のｐＨが測定され、ｐＨ検出部２４がその数値を検知する。ｐＨ検出部２４及びｐＨセンサー２６は、公知のものを適用することができる。なお、本実施形態において、ｐＨ検出部は必ずしも必要ではない。 The water softening device 10 further includes a pH detection unit 24 that detects the pH of the water to be treated. A pH sensor 26 is connected to the pH detection unit 24, the pH of the water to be treated is measured by the pH sensor 26, and the pH detection unit 24 detects the value. As the pH detector 24 and the pH sensor 26, known ones can be applied. In addition, in this embodiment, the pH detection unit is not always necessary.
　本実施形態において、軟水化装置１０は、さらに、被処理水の温度を調整する温度調整機構（不図示）を有することが好ましい。つまり、晶析は温度が高いほど進行しやすいため、温度調整機構により温度を高く設定することが好ましい。温度調整機構としては、被処理水の温度を調整できるものでれば特に制限はない。 In the present embodiment, it is preferable that the water softening device 10 further has a temperature adjusting mechanism (not shown) that adjusts the temperature of the water to be treated. That is, crystallization is more likely to proceed as the temperature increases, so it is preferable to set the temperature higher by the temperature adjusting mechanism. The temperature adjusting mechanism is not particularly limited as long as it can adjust the temperature of the water to be treated.
　また、軟水化装置１０には、被処理水１４を冷却するためのチラー２７を有する。被処理水１４は、超音波照射により発熱するため、チラー２７により循環冷却することが好ましい。 Further, the water softening device 10 has a chiller 27 for cooling the water 14 to be treated. Since the water to be treated 14 generates heat by irradiation with ultrasonic waves, it is preferable to circulate and cool the chiller 27.
　以上の図１に示す軟水化装置１０は、処理槽１２内に被処理水１４が滞留する態様である。本実施形態においては、流水としての被処理水を処理槽内に流入して軟水化し、その後、排出してもよい。図２は、軟水化の対象となる被処理水が流水の場合の軟水化装置を示す概念図である。図２に示す軟水化装置１１は、処理槽１３と、ｐＨ調整部１６と、種結晶供給部１８と、超音波照射部２０とを有する。処理槽１３には、流水としての被処理水１４を処理槽１３に流入させる流路２８と、処理を終えた被処理水１４を排出する流路３０とを備え、被処理水は流路２８を介して処理槽１３内に流入し、流路３０を介して排出される。その他、ｐＨ調整部１６、種結晶供給部１８、超音波照射部２０、及びｐＨ検出部２４は図１に示す軟水化装置１０と同様であり、同じ構成要素には同じ符号を付して説明を省略する。以下に、軟水化装置１０との相違点である処理槽１３と、流水たる被処理水について説明する。 The above-described water softening device 10 shown in FIG. 1 has a mode in which the water 14 to be treated stays in the treatment tank 12. In the present embodiment, the water to be treated as running water may flow into the treatment tank to be softened, and then discharged. FIG. 2 is a conceptual diagram showing a water softening device in the case where the water to be treated to be water softened is running water. The water softening device 11 shown in FIG. 2 includes a treatment tank 13, a pH adjusting unit 16, a seed crystal supplying unit 18, and an ultrasonic wave irradiating unit 20. The treatment tank 13 is provided with a flow passage 28 for allowing the treated water 14 as running water to flow into the treatment tank 13, and a passage 30 for discharging the treated water 14 that has been treated. It flows into the processing tank 13 via the and is discharged via the flow path 30. In addition, the pH adjusting unit 16, the seed crystal supplying unit 18, the ultrasonic wave irradiating unit 20, and the pH detecting unit 24 are the same as those in the water softening device 10 shown in FIG. Is omitted. Below, the treatment tank 13 which is a difference from the water softening device 10 and the water to be treated which is running water will be explained.
　処理槽１３は、図１に示す処理槽１２のような開口を有しておらず、流路２８及び流路３０を除き、外部とは連通していない。流路２８の上流側には、例えば、水道水の給水管が接続され、その場合、水道水が被処理水となる。そして、図１に示す軟水化装置１０と同様に、処理槽１３に流入する被処理水１４は、ｐＨ調整部１６によりｐＨ調整され、種結晶供給部１８により種結晶が供給される。そして、被処理水１４には超音波照射部２０により超音波が照射され、硬度成分が晶析して軟水化される。 The processing tank 13 does not have an opening like the processing tank 12 shown in FIG. 1, and does not communicate with the outside except for the channels 28 and 30. On the upstream side of the flow path 28, for example, a tap water supply pipe is connected, and in that case, tap water is the water to be treated. Then, similarly to the water softening device 10 shown in FIG. 1, the pH of the water to be treated 14 flowing into the treatment tank 13 is adjusted by the pH adjusting unit 16, and the seed crystal supplying unit 18 supplies the seed crystal. Then, the water to be treated 14 is irradiated with ultrasonic waves by the ultrasonic wave irradiation unit 20, and the hardness component is crystallized to be softened.
　被処理水が流水の場合、超音波照射による温度上昇は限定的であるため、チラーを設ける必要はない。また、流水であるが故に、ｐＨの調整は連続的に行うことを要する。例えば、ｐＨ検出部２４（ｐＨセンサー２６）により、ｐＨの値を検出しつつ、ｐＨが一定以下の数値となった場合にｐＨ調整するように設定することができる。また、流量に応じてｐＨ調整をするように設定することができる。 If the water to be treated is running water, the temperature rise due to ultrasonic irradiation is limited, so there is no need to install a chiller. Moreover, since it is running water, it is necessary to continuously adjust the pH. For example, the pH detection unit 24 (pH sensor 26) can be set to detect the pH value and adjust the pH when the pH value is below a certain value. Further, it can be set so as to adjust the pH according to the flow rate.
　以上の図１及び図２のいずれにおいても、軟水化後は種結晶を除去することが好ましい。種結晶を除去する手段としては特に限定はなく、公知の手段を適用することができる。
例えば、種結晶が通過しないフィルターに被処理水を通過させる手段等が挙げられる。 In both of the above FIG. 1 and FIG. 2, it is preferable to remove the seed crystal after water softening. The means for removing the seed crystal is not particularly limited, and known means can be applied.
For example, means for passing the water to be treated through a filter through which the seed crystal does not pass can be used.
＜軟水化方法＞
　本実施形態の軟水化方法は、軟水化の対象となる被処理水のｐＨを調整するステップＡと、軟水化の対象となる被処理水に、硬度成分の種結晶を供給するステップＢと、を順不同で含む。そして、ステップＡ及びステップＢの双方の実行後に、被処理水に超音波を照射するステップＣを含むことを特徴としている。 <Softening method>
The water softening method of the present embodiment includes a step A of adjusting the pH of the water to be treated which is the object of water softening, and a step B of supplying a seed crystal of a hardness component to the water to be treated which is the object of water softening, In any order. The method is characterized by including step C of irradiating the water to be treated with ultrasonic waves after performing both step A and step B.
　本実施形態の軟水化方法においては、まず、軟水化の対象となる被処理水のｐＨを調整し（ステップＡ）、硬度成分の種結晶を供給する（ステップＢ）。つまり、上述の通り、被処理水のｐＨを７．８以上に調整する。また、被処理水に、硬度成分の種結晶（炭酸塩）を供給する。次に、ｐＨが調整され、種結晶が供給された被処理水に対して超音波を照射する（ステップＣ）。すると、上述の通り、被処理水中において、超音波の密部でイオン濃度が高くなり、種結晶を核として炭酸塩が晶析する。すなわち、被処理水中において、硬度成分のイオンが減少することとなり、軟水化される。最終的には、晶析した種結晶は除去される。 In the water softening method of the present embodiment, first, the pH of the water to be treated to be water softened is adjusted (step A), and a seed crystal of hardness component is supplied (step B). That is, as described above, the pH of the water to be treated is adjusted to 7.8 or higher. Further, a seed crystal (carbonate) of the hardness component is supplied to the water to be treated. Next, ultrasonic waves are radiated to the water to be treated to which the pH has been adjusted and the seed crystals have been supplied (step C). Then, as described above, in the water to be treated, the ion concentration increases in the dense part of the ultrasonic waves, and the carbonate crystallizes with the seed crystal as the nucleus. That is, the ions of the hardness component are reduced in the water to be treated, and the water is softened. Finally, the crystallized seed crystals are removed.
　本実施形態の軟水化方法は、例えば、上述の本実施形態の軟水化装置により実行することができるが、当該軟水化装置に限定されることはない。少なくとも、器具類として、被処理水が収容される処理槽と、処理槽内の被処理水に超音波を照射する装置とがあり、試薬類としてｐＨ調整剤と種結晶とがあれば、本実施形態の軟水化方法を実行することができる。
　以下に、各ステップについて説明する。 The water softening method of the present embodiment can be executed by, for example, the water softening device of the present embodiment described above, but is not limited to the water softening device. At least, as the instruments, there is a treatment tank containing the water to be treated, and a device for irradiating the water to be treated in the treatment tank with ultrasonic waves. The water softening method of the embodiment can be executed.
Each step will be described below.
［ステップＡ］
　ステップＡでは、軟水化の対象となる被処理水のｐＨを調整する。当該ｐＨは、上述の通り、被処理水中における炭酸イオンの比率が大きくなるように調整する。ｐＨが大きいほど、炭酸イオンの比率が大きくなるため、晶析をより促進するには、被処理水のｐＨを７．８以上に調整することが好ましく、９．０以上に調整することが好ましい。 [Step A]
In step A, the pH of the water to be treated which is to be softened is adjusted. As described above, the pH is adjusted so that the ratio of carbonate ions in the water to be treated becomes large. The higher the pH, the higher the ratio of carbonate ions, and therefore the pH of the water to be treated is preferably adjusted to 7.8 or higher, more preferably 9.0 or higher in order to further promote crystallization. ..
　一方、上述の通り、ｐＨの調整にアルカリ剤を用いると、その消費に伴いｐＨが低下する。そのため、ｐＨが低下した場合、アルカリ剤を補充しないと炭酸イオンの比率が大きくならず、晶析が十分に進行しなくなる傾向にある。そこで、所定時間毎にアルカリ剤を補充してｐＨを調整することが好ましい。あるいは、ｐＨを検出し、ｐＨが一定以下になった場合にアルカリ剤を供給してｐＨを調整することもできる。 On the other hand, as mentioned above, if an alkaline agent is used to adjust the pH, the pH will decrease with its consumption. Therefore, when the pH is lowered, the ratio of carbonate ions does not increase unless the alkali agent is replenished, and crystallization tends not to proceed sufficiently. Therefore, it is preferable to replenish the alkaline agent every predetermined time to adjust the pH. Alternatively, the pH can be detected and an alkaline agent can be supplied to adjust the pH when the pH falls below a certain level.
　また、ステップＡにおいて、被処理水に緩衝剤を供給することが好ましい。被処理水に緩衝剤を供給することにより、被処理水のｐＨの変動を緩和することができる。つまり、上記のような、アルカリ剤を用いた場合のｐＨの低下を抑えることができる。緩衝剤の具体例としては、上述したのでここでは省略する。 Also, in step A, it is preferable to supply a buffer to the water to be treated. By supplying a buffering agent to the water to be treated, it is possible to mitigate fluctuations in the pH of the water to be treated. That is, it is possible to suppress the decrease in pH when the alkaline agent is used as described above. Specific examples of the buffering agent have been described above, and thus will be omitted here.
［ステップＢ］
　ステップＢでは、軟水化の対象となる被処理水に、硬度成分（カルシウム成分又はマグネシウム成分）の種結晶を供給する。カルシウム成分に対する種結晶としては、炭酸カルシウムが挙げられる。マグネシウム成分に対する種結晶としては、炭酸マグネシウムが挙げられる。 [Step B]
In step B, a seed crystal of hardness component (calcium component or magnesium component) is supplied to the water to be treated which is to be softened. Examples of seed crystals for the calcium component include calcium carbonate. Examples of the seed crystal for the magnesium component include magnesium carbonate.
　ステップＢにおいて、平均粒径が２μｍ未満の種結晶を供給することが好ましい。平均粒径が２μｍ未満の種結晶を供給する場合、その濃度に依存することなく十分な晶析を図ることができる。また、ステップＢにおいて、平均粒径が２μｍ未満の種結晶を供給する場合、被処理水中の種結晶の濃度を１００ｐｐｍ以上５００ｐｐｍ未満とすることが好ましく、３００ｐｐｍ以上５００ｐｐｍ未満とすることがより好ましい。
　また、ステップＢにおいて、平均粒径が２μｍ以上の種結晶を供給することが好ましい。ただし、平均粒径が２μｍ以上の種結晶を供給する場合、低濃度では十分な晶析を図ることができない場合がある。その場合、ステップＢにおいて、被処理水中の種結晶の濃度を５００ｐｐｍ以上とすることが好ましく、１０００ｐｐｍ以上とすることがより好ましい。 In step B, it is preferable to supply a seed crystal having an average particle size of less than 2 μm. When a seed crystal having an average particle size of less than 2 μm is supplied, sufficient crystallization can be achieved without depending on its concentration. Further, in step B, when a seed crystal having an average particle size of less than 2 μm is supplied, the concentration of the seed crystal in the water to be treated is preferably 100 ppm or more and less than 500 ppm, more preferably 300 ppm or more and less than 500 ppm.
Further, in step B, it is preferable to supply a seed crystal having an average particle size of 2 μm or more. However, when a seed crystal having an average particle size of 2 μm or more is supplied, sufficient crystallization may not be achieved at a low concentration. In that case, in step B, the concentration of the seed crystal in the water to be treated is preferably 500 ppm or more, more preferably 1000 ppm or more.
　なお、ステップＡ及びステップＢは順不同であり、ステップＡ及びステップＢのいずれを先に実行するかは問わない。 Note that Step A and Step B are in random order, and it does not matter which of Step A and Step B is executed first.
［ステップＣ］
　ステップＣでは、ステップＡ及びステップＢの双方の実行後に、被処理水に超音波を照射する。照射する超音波としては、周波数が２０ｋＨｚ以上であればよく、１ＭＨｚ以上が好ましい。また、超音波の照射時間は、被処理水の硬度に応じて設定することができる。すなわち、被処理水の硬度が高い場合は照射時間を長くし、硬度が低い場合は照射時間を短くすることができる。また、流水の場合は流速に応じて適宜設定することができる。 [Step C]
In step C, the water to be treated is irradiated with ultrasonic waves after execution of both step A and step B. The ultrasonic wave to be applied may have a frequency of 20 kHz or higher, preferably 1 MHz or higher. Further, the irradiation time of ultrasonic waves can be set according to the hardness of the water to be treated. That is, when the hardness of the water to be treated is high, the irradiation time can be extended, and when the hardness is low, the irradiation time can be shortened. Further, in the case of running water, it can be appropriately set according to the flow velocity.
　ステップＣにおいて、被処理水の温度を３０℃未満に調整することができる。すなわち、被処理水は常温以下とすることができる。常温以下の場合、通常であれば、晶析は進行しないか、又は進行したとしても進行速度は遅い傾向にあるが、本実施形態においては、超音波照射により被処理水が発熱するため、常温以下でも晶析が促進される。なお、被処理水の温度の下限は０℃である。
　また、ステップＣにおいて、被処理水の温度を３０℃以上に調整することができる。被処理水の温度が高ければ晶析が進行しやすい。そのため、加熱などにより温度を３０℃以上の温度とすることが好ましい。 In step C, the temperature of the water to be treated can be adjusted to less than 30°C. That is, the water to be treated can be kept at room temperature or lower. If the temperature is lower than room temperature, crystallization usually does not proceed, or the progress speed tends to be slow even if it progresses. Crystallization is promoted also below. The lower limit of the temperature of the water to be treated is 0°C.
In step C, the temperature of the water to be treated can be adjusted to 30°C or higher. If the temperature of the water to be treated is high, crystallization is likely to proceed. Therefore, it is preferable to set the temperature to 30° C. or higher by heating or the like.
　ステップＣを継続すると、アルカリ剤の消費及び被処理水のｐＨが低下する。そこで、被処理水のｐＨが低下したら（例えば、７．８未満）、アルカリ剤を添加することが好ましい。 ・Continuing Step C will reduce the consumption of alkaline agents and the pH of the water to be treated. Therefore, when the pH of the water to be treated decreases (for example, less than 7.8), it is preferable to add an alkaline agent.
　以上のステップＡ～Ｃを実行することで、硬水の軟水化を図ることができる。ただし、軟水化後においても、種結晶は残存するため除去することが好ましい。種結晶を除去する手法としては特に限定はなく、公知の手法を適用することができる。例えば、種結晶が通過しないフィルターに被処理水を通過させる手法等が挙げられる。 By performing steps A to C above, softening of hard water can be achieved. However, it is preferable to remove the seed crystals because they remain after the water softening. The method for removing the seed crystal is not particularly limited, and a known method can be applied. For example, a method of passing treated water through a filter through which seed crystals do not pass can be used.
　以上の本実施形態の軟水化装置及び軟水化方法は、使用場所設置型浄水装置（ＰＯＵ）や建物入口設置型浄水装置（ＰＯＥ）に適用することが可能である。 The water softening device and the water softening method of this embodiment described above can be applied to a place-of-use installed water purifier (POU) and a building entrance installed water purifier (POE).
　以下、実施例により本実施形態を更に詳しく説明するが、本実施形態はこれらに限定されるものではない。 Hereinafter, the present embodiment will be described in more detail by way of examples, but the present embodiment is not limited to these.
［実施例１］
　２００ｍｌのビーカーに被処理水としてエビアン（ダノンジャパン株式会社製、水温：２０℃）を満たし、水酸化ナトリウムを添加してｐＨを７．８に調整した。次いで、種結晶として炭酸カルシウム（平均粒径：０．１５μｍ）を濃度が１ｐｐｍとなるように添加した。その後、以下の条件により超音波を照射して軟水化を行った。なお、ビーカーにはチラーを接続し循環冷却を行い２０℃の温度を保った。
（超音波条件）
　超音波装置：ＳＯＮＩＦＩＥＲ４５０（株式会社池田理化製）
　出力：２０Ｗ　
　周波数：２５ｋＨｚ
　デューティサイクル：５０ [Example 1]
A 200 ml beaker was filled with Evian (manufactured by Danone Japan Co., Ltd., water temperature: 20° C.) as water to be treated, and sodium hydroxide was added to adjust the pH to 7.8. Next, calcium carbonate (average particle size: 0.15 μm) was added as a seed crystal so that the concentration was 1 ppm. After that, ultrasonic waves were applied under the following conditions to soften the water. A chiller was connected to the beaker, and circulation cooling was performed to maintain the temperature of 20°C.
(Ultrasonic conditions)
Ultrasonic device: SONIFIER450 (made by Rika Ikeda)
Output: 20W
Frequency: 25kHz
Duty cycle: 50
　所定の時間経過後、キレート滴定によりカルシウムイオン量を測定し、初期値からの減少率をカルシウムイオン減少率とした。処理時間に対するカルシウムイオン減少率を示すグラフを図３に示す。 After a lapse of a predetermined time, the amount of calcium ions was measured by chelate titration, and the reduction rate from the initial value was defined as the calcium ion reduction rate. A graph showing the reduction rate of calcium ions with respect to the treatment time is shown in FIG.
［比較例１］
　ｐＨの調整を行わなかったこと以外は実施例１と同様にして軟水化を行い、実施例１と同様にしてカルシウムイオン減少率を算出した。算出結果を示すグラフを図３に示す。 [Comparative Example 1]
Water softening was performed in the same manner as in Example 1 except that the pH was not adjusted, and the calcium ion reduction rate was calculated in the same manner as in Example 1. A graph showing the calculation result is shown in FIG.
　図３より、ｐＨ調整を行った実施例１の方が、ｐＨ調整を行わなかった比較例１よりも、時間の経過に対するカルシウムイオンの減少率の勾配が急であることが分かる。すなわち、ｐＨ調整により、十分に軟水化されることが示された。 From FIG. 3, it can be seen that the gradient of the decrease rate of calcium ions with time is steeper in Example 1 with pH adjustment than in Comparative Example 1 without pH adjustment. That is, it was shown that the pH was adjusted to sufficiently soften the water.
［実施例２］
　実施例１において、初期のｐＨを８．１とし、その後同様の処理を６０分間実行した。処理時間に対するｐＨの変化を示すグラフを図４に示す。また、処理時間に対するカルシウムイオンの除去率を示すグラフを図５に示す。 [Example 2]
In Example 1, the initial pH was set to 8.1, and then the same treatment was performed for 60 minutes. A graph showing the change in pH with the treatment time is shown in FIG. Further, a graph showing the removal rate of calcium ions with respect to the treatment time is shown in FIG.
［実施例３］
　実施例２において、５分毎に水酸化ナトリウムを補充してｐＨを調整しつつ１時間軟水化を行った。経過時間に対するｐＨの変化を図６のグラフに示す。また、処理時間に対するカルシウムイオンの除去率を図７のグラフに示す。 [Example 3]
In Example 2, water was softened for 1 hour while replenishing sodium hydroxide every 5 minutes to adjust the pH. The change in pH with time is shown in the graph of FIG. The graph of FIG. 7 shows the removal rate of calcium ions with respect to the treatment time.
　図４～５より、ｐＨは経時的に低下し、それに伴いカルシウムイオンの除去率が減少することが分かる。また、図６～７より、所定時間毎にアルカリ剤を補充した方がｐＨの低下が抑えられ、カルシウムイオンの除去率が向上していることが分かる。 From FIGS. 4 to 5, it can be seen that the pH decreases with time and the removal rate of calcium ions decreases accordingly. Further, it can be seen from FIGS. 6 to 7 that when the alkaline agent is replenished at predetermined intervals, the decrease in pH is suppressed and the removal rate of calcium ions is improved.
［実施例４］
　２００ｍｌのビーカーに被処理水としてエビアン（ダノンジャパン株式会社製、水温：２０℃）を満たし、水酸化ナトリウムを添加してｐＨを８．１に調整した。次いで、種結晶として炭酸カルシウム（平均粒径：０．１５μｍ）を濃度が１００ｐｐｍとなるように添加した。その後、以下の条件により超音波を照射して軟水化を行った。なお、ビーカーにはチラーを接続し循環冷却を行い２０℃の温度を保った。
（超音波条件）
　超音波装置：超音波霧化ユニット（ＩＭ１－２４／ＬＷ、株式会社星光技研製）
　出力：１７Ｗ
　周波数：１６００ｋＨｚ
　デューティサイクル：１００ [Example 4]
A 200 ml beaker was filled with Evian (manufactured by Danone Japan Co., Ltd., water temperature: 20° C.) as water to be treated, and sodium hydroxide was added to adjust the pH to 8.1. Next, calcium carbonate (average particle diameter: 0.15 μm) was added as a seed crystal so that the concentration was 100 ppm. After that, ultrasonic waves were applied under the following conditions to soften the water. A chiller was connected to the beaker, and circulation cooling was performed to maintain the temperature of 20°C.
(Ultrasonic conditions)
Ultrasonic device: Ultrasonic atomization unit (IM1-24/LW, manufactured by Seikou Giken Co., Ltd.)
Output: 17W
Frequency: 1600kHz
Duty cycle: 100
［実施例５］
　水酸化ナトリウムの代わりにトリス緩衝剤（０．１Ｍ）を用い、初期のｐＨを約９としたこと以外は実施例４と同様にして軟水化を行った。 [Example 5]
Water softening was performed in the same manner as in Example 4 except that Tris buffer (0.1 M) was used instead of sodium hydroxide and the initial pH was adjusted to about 9.
　実施例４及び５における、処理時間に対するｐＨの変化を示すグラフを図８に示す。また、処理時間に対するカルシウムイオンの除去率を示すグラフを図９に示す。 FIG. 8 shows a graph showing changes in pH with respect to treatment time in Examples 4 and 5. Further, FIG. 9 shows a graph showing the removal rate of calcium ions with respect to the treatment time.
　図８より、トリス緩衝剤を用いた実施例５は、トリス緩衝剤を添加後、何もしていないにもかかわらず経時的なｐＨの変動が小さいことが分かる。そして、図９より、処理時間に対するカルシウムイオンの除去率は、５分経過後は７０～７５％の範囲で安定していることが分かる。 From FIG. 8, it can be seen that in Example 5 using the Tris buffer, the change in pH with time is small after adding the Tris buffer, even though nothing is done. From FIG. 9, it can be seen that the removal rate of calcium ions with respect to the treatment time is stable in the range of 70 to 75% after 5 minutes.
［実施例６－１］
　２００ｍｌのビーカーに被処理水としてエビアン（ダノンジャパン株式会社製、水温：２０℃）を満たし、トリス緩衝剤（０．１Ｍ）を添加した。次いで、種結晶（平均粒径：０．１５μｍ）として炭酸カルシウムを濃度が１０ｐｐｍとなるように添加した。その後、以下の条件により超音波を照射して軟水化を行った。
（超音波条件）
　超音波装置：超音波霧化ユニット（ＩＭ１－２４／ＬＷ、株式会社星光技研製）
　出力：１７Ｗ　
　周波数：１６００ｋＨｚ
　デューティサイクル：１００
　超音波照射時間：１分 [Example 6-1]
A 200 ml beaker was filled with Evian (manufactured by Danone Japan Co., Ltd., water temperature: 20° C.) as water to be treated, and a Tris buffer (0.1 M) was added. Next, calcium carbonate was added as a seed crystal (average particle size: 0.15 μm) so that the concentration would be 10 ppm. After that, ultrasonic waves were applied under the following conditions to soften the water.
(Ultrasonic conditions)
Ultrasonic device: Ultrasonic atomization unit (IM1-24/LW, manufactured by Seikou Giken Co., Ltd.)
Output: 17W
Frequency: 1600kHz
Duty cycle: 100
Ultrasonic irradiation time: 1 minute
［実施例６－２］
　炭酸カルシウムを濃度が１００ｐｐｍとなるように添加したこと以外は実施例６－１と同様にして軟水化を行った。 [Example 6-2]
Water softening was performed in the same manner as in Example 6-1, except that calcium carbonate was added so as to have a concentration of 100 ppm.
［実施例６－３］
　炭酸カルシウムを濃度が５００ｐｐｍとなるように添加したこと以外は実施例６－１と同様にして軟水化を行った。 [Example 6-3]
Water softening was performed in the same manner as in Example 6-1, except that calcium carbonate was added so as to have a concentration of 500 ppm.
［実施例６－４］
　炭酸カルシウムを濃度が１０００ｐｐｍとなるように添加したこと以外は実施例６－１と同様にして軟水化を行った。 [Example 6-4]
Water softening was performed in the same manner as in Example 6-1 except that calcium carbonate was added so as to have a concentration of 1000 ppm.
［実施例７－１］
　種結晶として、平均粒径が１．２μｍの炭酸カルシウムを用いたこと以外は実施例６－１と同様にして軟水化を行った。 [Example 7-1]
Water softening was performed in the same manner as in Example 6-1 except that calcium carbonate having an average particle size of 1.2 μm was used as a seed crystal.
［実施例７－２］
　炭酸カルシウムを濃度が１００ｐｐｍとなるように添加したこと以外は実施例７－１と同様にして軟水化を行った。 [Example 7-2]
Water softening was performed in the same manner as in Example 7-1, except that calcium carbonate was added so as to have a concentration of 100 ppm.
［実施例７－３］
　炭酸カルシウムを濃度が５００ｐｐｍとなるように添加したこと以外は実施例７－１と同様にして軟水化を行った。 [Example 7-3]
Water softening was performed in the same manner as in Example 7-1 except that calcium carbonate was added so that the concentration would be 500 ppm.
［実施例７－４］
　炭酸カルシウムを濃度が１０００ｐｐｍとなるように添加したこと以外は実施例７－１と同様にして軟水化を行った。 [Example 7-4]
Water softening was performed in the same manner as in Example 7-1 except that calcium carbonate was added so that the concentration became 1000 ppm.
［実施例８－１］
　種結晶として、平均粒径が４．０μｍの炭酸カルシウムを用いたこと以外は実施例６－１と同様にして軟水化を行った。 [Example 8-1]
Water softening was performed in the same manner as in Example 6-1 except that calcium carbonate having an average particle size of 4.0 μm was used as a seed crystal.
［実施例８－２］
　炭酸カルシウムを濃度が１００ｐｐｍとなるように添加したこと以外は実施例８－１と同様にして軟水化を行った。 [Example 8-2]
Water softening was performed in the same manner as in Example 8-1, except that calcium carbonate was added so that the concentration became 100 ppm.
［実施例８－３］
　炭酸カルシウムを濃度が５００ｐｐｍとなるように添加したこと以外は実施例８－１と同様にして軟水化を行った。 [Example 8-3]
Water softening was performed in the same manner as in Example 8-1, except that calcium carbonate was added so that the concentration was 500 ppm.
［実施例８－４］
　炭酸カルシウムを濃度が１０００ｐｐｍとなるように添加したこと以外は実施例８－１と同様にして軟水化を行った。 [Example 8-4]
Water softening was performed in the same manner as in Example 8-1 except that calcium carbonate was added so as to have a concentration of 1000 ppm.
［実施例９－１］
　種結晶として、平均粒径が８．０μｍの炭酸カルシウムを用いたこと以外は実施例６－１と同様にして軟水化を行った。 [Example 9-1]
Water softening was performed in the same manner as in Example 6-1 except that calcium carbonate having an average particle size of 8.0 μm was used as a seed crystal.
［実施例９－２］
　炭酸カルシウムを濃度が１００ｐｐｍとなるように添加したこと以外は実施例９－１と同様にして軟水化を行った。 [Example 9-2]
Water softening was performed in the same manner as in Example 9-1 except that calcium carbonate was added so as to have a concentration of 100 ppm.
［実施例９－３］
　炭酸カルシウムを濃度が５００ｐｐｍとなるように添加したこと以外は実施例９－１と同様にして軟水化を行った。 [Example 9-3]
Water softening was performed in the same manner as in Example 9-1 except that calcium carbonate was added so as to have a concentration of 500 ppm.
［実施例９－４］
　炭酸カルシウムを濃度が１０００ｐｐｍとなるように添加したこと以外は実施例９－１と同様にして軟水化を行った。 [Example 9-4]
Water softening was performed in the same manner as in Example 9-1 except that calcium carbonate was added so as to have a concentration of 1000 ppm.
　実施例６－１～９－４において、炭酸カルシウムの濃度に対するｐＨの変化を示すグラフを図１０に示す。同様に、炭酸カルシウムの濃度に対するカルシウムイオンの除去率を示すグラフを図１１に示す。 FIG. 10 shows a graph showing changes in pH with respect to the concentration of calcium carbonate in Examples 6-1 to 9-4. Similarly, FIG. 11 shows a graph showing the removal rate of calcium ions with respect to the concentration of calcium carbonate.
　図１０より、炭酸カルシウムの平均粒径が小さいほど、又は濃度が高いほど反応が早くなり、初期ｐＨが低下することが分かる。また、図１１より、炭酸カルシウムが低濃度であっても、その平均粒径が小さいほどカルシウムイオンの除去率が高い傾向にあることが分かる。 From FIG. 10, it can be seen that the smaller the average particle size of calcium carbonate or the higher the concentration, the faster the reaction and the lower the initial pH. Further, it can be seen from FIG. 11 that even if the concentration of calcium carbonate is low, the smaller the average particle size, the higher the removal rate of calcium ions.
　特願２０１９－１５４３５（出願日：２０１９年１月３１日）の全内容は、ここに援用される。 The entire contents of Japanese Patent Application No. 2019-15435 (filing date: January 31, 2019) are hereby incorporated by reference.
　本実施形態によれば、硬水の軟水化を簡単な構成で実現することができる軟水化装置及び軟水化方法を提供することができる。 According to the present embodiment, it is possible to provide a water softening device and a water softening method that can realize softening of hard water with a simple configuration.
１０　１１　軟水化装置
１２　１３　処理槽
１４　被処理水
１６　ｐＨ調整部
１８　種結晶供給部
２０　超音波照射部
２２　振動子 10 11 Water softening device 12 13 Treatment tank 14 Treated water 16 pH adjusting unit 18 Seed crystal supply unit 20 Ultrasonic wave irradiating unit 22 Transducer

Claims (16)

  1. 　軟水化の対象となる被処理水が投入される処理槽と、
    　前記被処理水のｐＨを調整するｐＨ調整部と、
    　前記被処理水に硬度成分の種結晶を供給する種結晶供給部と、
    　前記被処理水に超音波を照射する超音波照射部と、
    を有する、軟水化装置。     A treatment tank into which water to be treated, which is the target of water softening, is input,
    A pH adjusting unit for adjusting the pH of the water to be treated,
    A seed crystal supply unit for supplying a seed crystal of a hardness component to the water to be treated,
    An ultrasonic wave irradiation unit for irradiating the water to be treated with ultrasonic waves,
    And a water softening device.
  2. 　前記ｐＨ調整部によって調整されるｐＨが７．８以上である、請求項１に記載の軟水化装置。 The water softener according to claim 1, wherein the pH adjusted by the pH adjuster is 7.8 or higher.
  3. 　前記ｐＨ調整部によって調整されるｐＨが９．０以上である、請求項２に記載の軟水化装置。 The water softener according to claim 2, wherein the pH adjusted by the pH adjuster is 9.0 or higher.
  4. 　さらに、前記被処理水の温度を調整する温度調整機構を有する、請求項１～３のいずれか１項に記載の軟水化装置。 The water softening device according to any one of claims 1 to 3, further comprising a temperature adjusting mechanism for adjusting the temperature of the water to be treated.
  5. 　前記種結晶供給部により供給される種結晶の粒径が２μｍ未満である、請求項１～４のいずれか１項に記載の軟水化装置。 The water softening device according to any one of claims 1 to 4, wherein the seed crystal supplied by the seed crystal supply unit has a particle size of less than 2 µm.
  6. 　前記種結晶供給部により供給される種結晶の粒径が２μｍ以上である、請求項１～４のいずれか１項に記載の軟水化装置。 The water softening device according to any one of claims 1 to 4, wherein the seed crystal supplied by the seed crystal supply unit has a particle size of 2 µm or more.
  7. 　軟水化の対象となる被処理水のｐＨを調整するステップＡと、
    　軟水化の対象となる被処理水に、硬度成分の種結晶を供給するステップＢと、を順不同で含み、
    　前記ステップＡ及び前記ステップＢの双方の実行後に、前記被処理水に超音波を照射するステップＣを含む、軟水化方法。     Step A of adjusting the pH of the water to be treated which is to be softened,
    Step B for supplying a seed crystal of a hardness component to the water to be treated to be softened is included in no particular order,
    A method of water softening, comprising a step C of irradiating the water to be treated with ultrasonic waves after performing both the step A and the step B.
  8. 　前記ステップＡにおいて、前記被処理水のｐＨを７．８以上に調整する、請求項７に記載の軟水化方法。 The water softening method according to claim 7, wherein the pH of the water to be treated is adjusted to 7.8 or higher in the step A.
  9. 　前記ステップＡにおいて、前記被処理水のｐＨを９．０以上に調整する、請求項８に記載の軟水化方法。 The water softening method according to claim 8, wherein in the step A, the pH of the water to be treated is adjusted to 9.0 or higher.
  10. 　前記ステップＡにおいて、前記被処理水に緩衝剤を供給する、請求項７～９のいずれか１項に記載の軟水化方法。 The water softening method according to any one of claims 7 to 9, wherein a buffer is supplied to the water to be treated in the step A.
  11. 　前記ステップＢにおいて、平均粒径が２μｍ未満の種結晶を供給する、請求項７～１０のいずれか１項に記載の軟水化方法。 The water softening method according to any one of claims 7 to 10, wherein seed crystals having an average particle size of less than 2 µm are supplied in the step B.
  12. 　前記ステップＢにおいて、平均粒径が２μｍ以上の種結晶を供給する、請求項７～１０のいずれか１項に記載の軟水化方法。 The water softening method according to any one of claims 7 to 10, wherein seed crystals having an average particle size of 2 µm or more are supplied in the step B.
  13. 　前記ステップＢにおいて、前記被処理水中の種結晶の濃度を１００ｐｐｍ以上５００ｐｐｍ未満とする、請求項１１に記載の軟水化方法。 The water softening method according to claim 11, wherein the concentration of the seed crystal in the water to be treated is 100 ppm or more and less than 500 ppm in the step B.
  14. 　前記ステップＢにおいて、前記被処理水中の種結晶の濃度を５００ｐｐｍ以上とする、
    請求項１２に記載の軟水化方法。     In the step B, the concentration of the seed crystal in the water to be treated is 500 ppm or more,
    The water softening method according to claim 12.
  15. 　前記ステップＣにおいて、前記被処理水の温度を３０℃未満に調整する、請求項７～１４のいずれか１項に記載の軟水化方法。 The water softening method according to any one of claims 7 to 14, wherein in the step C, the temperature of the water to be treated is adjusted to be lower than 30°C.
  16. 　前記ステップＣにおいて、前記被処理水の温度を３０℃以上に調整する、請求項７～１４のいずれか１項に記載の軟水化方法。 The water softening method according to any one of claims 7 to 14, wherein in step C, the temperature of the water to be treated is adjusted to 30°C or higher.
PCT/JP2020/002301 2019-01-31 2020-01-23 Water softening apparatus and water softening method WO2020158565A1 (en)

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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02102796A (en) * 1988-08-23 1990-04-16 Dhv Raadgevend Ing Bv Chemical softening of water
JP2003117588A (en) * 2001-10-16 2003-04-22 Kurita Water Ind Ltd Apparatus for preventing attachment of scale
JP2003170192A (en) * 2001-12-11 2003-06-17 Kurita Water Ind Ltd Method for preventing scale in water circulating system
JP2003260496A (en) * 2002-03-11 2003-09-16 Kurita Water Ind Ltd Method for preventing adhesion of scale
US20050145570A1 (en) * 2002-10-16 2005-07-07 Anthony Pipes Method and apparatus for parallel desalting
JP2008207166A (en) * 2007-01-31 2008-09-11 Tokyo Gas Co Ltd Drainage recycling method
JP2012523316A (en) * 2009-04-10 2012-10-04 シルバン ソース， インコーポレイテッド Method and system for reducing scaling in aqueous solution purification
JP2012524653A (en) * 2009-04-21 2012-10-18 イーコラブ ユーエスエー インコーポレイティド Catalytic water treatment method and apparatus

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02102796A (en) * 1988-08-23 1990-04-16 Dhv Raadgevend Ing Bv Chemical softening of water
JP2003117588A (en) * 2001-10-16 2003-04-22 Kurita Water Ind Ltd Apparatus for preventing attachment of scale
JP2003170192A (en) * 2001-12-11 2003-06-17 Kurita Water Ind Ltd Method for preventing scale in water circulating system
JP2003260496A (en) * 2002-03-11 2003-09-16 Kurita Water Ind Ltd Method for preventing adhesion of scale
US20050145570A1 (en) * 2002-10-16 2005-07-07 Anthony Pipes Method and apparatus for parallel desalting
JP2008207166A (en) * 2007-01-31 2008-09-11 Tokyo Gas Co Ltd Drainage recycling method
JP2012523316A (en) * 2009-04-10 2012-10-04 シルバン ソース， インコーポレイテッド Method and system for reducing scaling in aqueous solution purification
JP2012524653A (en) * 2009-04-21 2012-10-18 イーコラブ ユーエスエー インコーポレイティド Catalytic water treatment method and apparatus

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