WO2018088015A1 - Regeneration method for multilayer anion exchange column - Google Patents

Regeneration method for multilayer anion exchange column Download PDF

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Publication number
WO2018088015A1
WO2018088015A1 PCT/JP2017/032488 JP2017032488W WO2018088015A1 WO 2018088015 A1 WO2018088015 A1 WO 2018088015A1 JP 2017032488 W JP2017032488 W JP 2017032488W WO 2018088015 A1 WO2018088015 A1 WO 2018088015A1
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Prior art keywords
anion exchange
exchange resin
resin layer
layer
basic anion
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PCT/JP2017/032488
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French (fr)
Japanese (ja)
Inventor
中馬　高明
重希 堀井
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栗田工業株式会社
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Priority to CN201780067724.XA priority Critical patent/CN109906115A/en
Publication of WO2018088015A1 publication Critical patent/WO2018088015A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J41/00—Anion exchange; Use of material as anion exchangers; Treatment of material for improving the anion exchange properties
    • B01J41/04—Processes using organic exchangers
    • B01J41/05—Processes using organic exchangers in the strongly basic form
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J41/00—Anion exchange; Use of material as anion exchangers; Treatment of material for improving the anion exchange properties
    • B01J41/04—Processes using organic exchangers
    • B01J41/07—Processes using organic exchangers in the weakly basic form
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J47/00—Ion-exchange processes in general; Apparatus therefor
    • B01J47/02—Column or bed processes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J49/00—Regeneration or reactivation of ion-exchangers; Apparatus therefor
    • B01J49/05—Regeneration or reactivation of ion-exchangers; Apparatus therefor of fixed beds
    • B01J49/07—Regeneration or reactivation of ion-exchangers; Apparatus therefor of fixed beds containing anionic exchangers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J49/00—Regeneration or reactivation of ion-exchangers; Apparatus therefor
    • B01J49/50—Regeneration or reactivation of ion-exchangers; Apparatus therefor characterised by the regeneration reagents
    • B01J49/57—Regeneration or reactivation of ion-exchangers; Apparatus therefor characterised by the regeneration reagents for anionic exchangers
    • 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
    • C02F1/42—Treatment of water, waste water, or sewage by ion-exchange

Definitions

  • the present invention comprises a weakly basic anion exchange resin layer and a strongly basic anion exchange resin layer, and the water to be treated is passed through the weakly basic anion exchange resin layer to the strongly basic anion exchange resin layer in this order.
  • the present invention also relates to a method for regenerating a multilayer anion exchange column.
  • Anion exchange resins used for the production of pure water and the like are strongly basic anion exchange resins (hereinafter "SA”) for adsorbing and removing some strong acid components and weak acid components such as silica, boron and carbonic acid. And a weakly basic anion exchange resin (hereinafter sometimes abbreviated as “WA”) for adsorbing and removing strong acid components such as sulfate ions and chloride ions. Broadly divided.
  • SA strongly basic anion exchange resins
  • WA weakly basic anion exchange resin
  • SA and WA have different holding powers for ions adsorbed depending on the nature of the ion exchange group in the structure, SA has a strong holding power, and WA has a low holding power.
  • anion exchange towers there are a single-layer system using a tower equipped with only SA and a multi-layer system using a tower equipped with both WA and SA resins.
  • treated water usually treated water after passing through the cation exchange tower
  • WA layer the WA layer
  • SA layer the SA layer
  • the multi-layer type anion exchange tower there are a two-column system in which WA and SA are packed in separate towers, and a single-column system in which the same tower is packed so that WA and SA are layered. is there.
  • the WA layer and the SA layer are usually partitioned by a water-permeable partition plate.
  • the SA layer is adsorbed with weak acid components such as silica, boron, and carbonic acid, and strong acid components that are not adsorbed by the WA layer but partially leaked from the WA layer. Most of the strong acid load is adsorbed on the WA layer.
  • the multi-layer anion exchange tower is usually regenerated by passing a sodium hydroxide (NaOH) aqueous solution as a regenerant in the order of SA layer ⁇ WA layer. This is due to the following reason.
  • NaOH sodium hydroxide
  • SA and WA have different retention of adsorbed ions, but the regeneration efficiency differs depending on the strength of this retention. Since WA with weak holding power is regenerated with a small amount of regenerant, the regenerant is passed through in the order of SA layer ⁇ WA layer, and the regenerant that was not used in the SA layer is used in the WA layer.
  • Non-patent Document 1 When regenerating SA, a regenerant heated to 40 to 50 ° C. is often used to increase the desorption rate of silica adsorbed on the resin.
  • the regeneration waste liquid of the SA layer contains a high concentration of silica.
  • gelation of silica occurs in the WA layer (Non-patent Document 1). This is because when the WA is regenerated, the strong acid component that has been adsorbed is desorbed, whereby the pH of the regenerated solution is drastically lowered and the solubility of silica is lowered.
  • Patent Document 1 As a method for preventing gelation of silica, there is a method in which the concentration of desorbed silica is changed by adjusting the sodium hydroxide concentration of the regenerant during regeneration (Patent Document 1). However, this method has a silica solubility of about 7.5 g-SiO 2 / L even in a 1% low-concentration NaOH aqueous solution. The silica is gelled by lowering.
  • this method even if the concentration of silica can be reduced, the elimination of strong acid cannot be controlled in the WA layer, and gelation remains unchanged.
  • the timing for changing the temperature is not clear, and if the timing is late, there is a risk that the reproduction is insufficient and potentially a reproduction failure is caused.
  • the amount of pure water used for regeneration increases, which is not economical.
  • An object of the present invention is to suppress the gelation of silica at the time of regenerating a multi-layered anion exchange column and to perform efficient regeneration.
  • the present inventor has found that the gelation of silica in the WA layer can be prevented by performing the predetermined first regeneration step and second regeneration step.
  • the gist of the present invention is as follows.
  • a weakly basic anion exchange resin layer and a strongly basic anion exchange resin layer are provided, and water to be treated is passed through the weakly basic anion exchange resin layer and the strong base anion exchange resin layer in this order.
  • the regenerant is the multilayer anion.
  • a regeneration method for a multilayer anion exchange column comprising performing a regeneration step and a second regeneration step of regenerating the strongly basic anion exchange resin layer after the first regeneration step.
  • [2] A method for regenerating a multi-layered anion exchange column according to [1], wherein the first regeneration step is performed until the pH of the front tower effluent becomes 9 or more.
  • the step (i) is performed, and then in the second regeneration step, the regenerant is added to the multilayer anion exchange column.
  • the strong basic anion exchange resin layer is introduced from the strong basic anion exchange resin layer side and then passed through the strong basic anion exchange resin layer in the order of the weak basic anion exchange resin layer to flow out of the tower, thereby the strong basic anion exchange.
  • a weakly basic anion exchange resin layer and a strongly basic anion exchange resin layer are provided, and water to be treated is passed through the weakly basic anion exchange resin layer to the strong base anion exchange resin layer in this order.
  • the regenerant is the multilayer anion.
  • a regeneration method for a multi-layered anion exchange column comprising a first regeneration step that continues until the pH becomes alkaline and a second regeneration step that regenerates the strongly basic anion exchange resin layer, Performing the step and the second regeneration step at the same time, in the second regeneration step, A multi-layer system wherein the regenerant used for regenerating the basic anion exchange resin layer is discharged out of the multi-layer anion exchange tower without passing through the weak base anion exchange resin layer. Regeneration method of anion exchange tower.
  • the strongly basic anion exchange resin in the multilayer anion exchange tower through which the regenerant is passed adsorbs and holds silica
  • the temperature at the time of passing the water to be treated is maintained in the range of 5 to 20 ° C. prior to the first regeneration step. Regeneration method of anion exchange tower.
  • the present invention it is possible to suppress the gelation of silica at the time of regenerating the multi-layered anion exchange tower and perform efficient regeneration.
  • FIG. 1 is a graph showing changes over time in the Cl ion concentration, ionic silica concentration, colloidal silica concentration, and pH of the regenerated waste liquid in Experimental Example 1.
  • a multilayer anion exchange tower for regeneration comprises a weakly basic anion exchange resin (WA) layer and a strongly basic anion exchange resin (SA) layer.
  • the multi-layered anion exchange tower may be a single tower type in which the WA layer and the SA layer are provided in one tower.
  • the multi-layered anion exchange column may be a two-column type in which WA and SA are packed in separate columns.
  • the water to be treated When collecting the water to be treated by passing it through the multi-layer anion exchange tower, the water to be treated is passed in the order from the WA layer to the SA layer.
  • the WA layer by passing water to be treated, strong acid components are adsorbed and retained in the WA layer, and weak acid components such as silica, boron, carbonic acid, etc., and the SA layer cannot be removed by the WA layer.
  • the multi-layer anion exchange tower that adsorbs and holds the strong acid component that has flowed into the column is regenerated.
  • the multi-layer anion exchange tower is regenerated in a regeneration step consisting of a first regeneration step and a second regeneration step, which will be described later.
  • a cleaning step is performed. Extrusion washing is performed until the pH of the column effluent during extrusion washing reaches about 10-12. If necessary, after the extrusion washing process, in order to increase the purity of the tower effluent and start sampling, the water to be treated and pure water are washed in the same direction as the water flow direction during sampling.
  • the tower effluent is treated with a cation exchange tower and a decarboxylation tower, and then circulated and passed to obtain a tower effluent with a desired purity.
  • a series of processes for regeneration is completed, and water sampling, that is, production of pure water is resumed.
  • the water to be treated Prior to regeneration of the multi-layer anion exchange tower, the water to be treated is cooled to 5 to 20 ° C., preferably 5 to 15 ° C. at the time of sampling, and the multi-layer anion exchange tower is passed through the multi-layer anion exchange tower. It is preferable to carry out the step of maintaining the inside of the formula anion exchange column at such a low temperature. This is due to the following reason.
  • the water sampling step is performed at such a low temperature to suppress the polymerization of silica in the multi-layer anion exchange tower, and the silica in the regeneration step Increases detachability and enables efficient regeneration. For this reason, when the temperature of to-be-processed water is high, it is preferable to lower the temperature of to-be-processed water to the said range, and to flow through a multilayer anion exchange tower.
  • the NaOH aqueous solution as the regenerant has a NaOH concentration of 0.5 to 5.0% by weight (usually pH 13 or more) from the viewpoint of regeneration efficiency. If the NaOH concentration is lower than the lower limit, it is inefficient because ions having a large selection coefficient are exchanged with OH ions having a small selection coefficient as a regenerant. When the NaOH concentration is higher than the above upper limit, the speed does not increase from the viewpoint of penetration into the resin, which is inefficient.
  • the water flow direction during sampling is often a downward flow, and therefore the liquid flow direction during regeneration is preferably an upward flow.
  • the liquid passing direction at the time of the above-described extrusion cleaning is preferably the same as the flow direction of the regenerant.
  • the temperature of the regenerant is as follows.
  • the temperature of the regenerant that is passed through only the WA layer may be 5 ° C. or more and 55 ° C. or less, which is a range heated from room temperature, and is usually 5 ° C. or more and less than 35 ° C. (water temperature in cold regions or summer). ), Preferably 20 ° C. or higher and 30 ° C. or lower.
  • the temperature of the regenerant that is passed through only the SA layer may be 5 ° C. or higher and 55 ° C. or lower, which is a range warmed from normal temperature, and is usually 35 ° C. or higher and 55 ° C. or lower, preferably 40 ° C. or higher. Most preferred is 45 ° C or lower.
  • the regenerant that is continuously passed from the SA layer to the WA layer is preferably 5 ° C. or higher and 55 ° C. or lower.
  • a regenerant at room temperature (5 ° C. or more and less than 35 ° C., preferably 20 ° C. or more and 30 ° C. or less) is used by setting the immersion time to 30 minutes or more. Can do.
  • the flow rate of the regenerant is preferably set to the following amount based on the load of the multilayer anion exchange tower to be regenerated or the pH of the tower effluent (regeneration waste liquid).
  • the flow rate of the regenerant is such that the molar ratio of NaOH passed is 100% or more, preferably 110 to 135% with respect to the design load (the amount of ions to be desorbed) of the regenerative multilayer anion exchange column. It is preferable to use an amount.
  • the NaOH molar ratio with respect to the design load may be set for the overall design load of the WA layer and the SA layer, or may be set for the design load of each layer individually. Also, the actual operational load may be analyzed and set for this value.
  • the pH of the column effluent (regeneration waste liquid) that has passed through the SA layer is 9 or higher, preferably 10 or higher, more preferably 13 or higher. It is preferable to make it an amount.
  • the amount of the tower effluent (regenerated waste liquid) that has passed through the WA layer is preferably 9 or more, preferably 10 or more, more preferably 13 or more.
  • the tower effluent discharged from the WA layer side in the order of the SA layer ⁇ WA layer (recycled waste liquid discharged from the WA layer) It is preferable to adjust the pH to 9 or more, preferably 10 to 13.
  • a dipping step may be performed in which the passing is stopped and held for a predetermined time.
  • the timing of starting the immersion is the time when the flow rate of the regenerant reaches the aforementioned amount.
  • the immersion temperature (the temperature of the regenerant held in the tower in the immersion step) varies depending on the immersion time, but is usually 5 ° C. or higher and 55 ° C. or lower, preferably normal temperature (5 ° C. or higher and lower than 35 ° C., preferably 20 ° C. or higher). 30 ° C. or lower).
  • the dipping process is usually 20 minutes or more, preferably about 30 to 120 minutes.
  • a step of introducing the regenerant from between the WA layer and the SA layer of the multi-layered anion exchange tower and allowing only the WA layer to pass through or (ii) a regenerant
  • the step of introducing from the SA layer side of the multi-layered anion exchange tower and passing it through the SA layer to the WA layer in order is carried out, and the pH of the tower effluent is alkaline, preferably pH 9 or higher, more preferably pH 10 or higher.
  • a first regeneration process that continues until the first regeneration process is performed, and a second regeneration process for regenerating the SA layer is performed after the first regeneration process.
  • Examples of the method for regenerating the SA layer in the second regeneration step include the following methods.
  • the regenerant is introduced from between the WA layer and the SA layer of the multi-layer anion exchange tower, and only the SA layer is allowed to flow out from the SA layer side of the tower, or the regenerant is mixed. It introduce
  • a regenerant is introduced from the SA layer side of the multi-layered anion exchange tower, passed from the SA layer to the WA layer in this order, and discharged from the WA layer side of the tower.
  • a regenerant is introduced from the SA layer side of the multi-layered anion exchange column to perform immersion regeneration of the SA layer.
  • the first regeneration step By adopting the step (i), the first regeneration step and the second regeneration step can be performed simultaneously.
  • Such regeneration of only the SA layer and regeneration of only the WA layer are performed using a multi-layer anion exchange tower provided with a regenerant introduction pipe and a regeneration waste liquid discharge pipe between the WA layer and the SA layer. be able to.
  • the regenerant in the first regeneration step, is passed through until the pH of the column effluent becomes alkaline, preferably pH 9 or more, more preferably pH 10 or more, and then the SA layer is regenerated, so that WA Silica gelation in the layer can be prevented. This is due to the following reason.
  • the pH of the column effluent that has passed through the WA layer is alkaline, preferably pH 9 or higher, more preferably pH 10 or higher. It means that the strong acid component adsorbed on the layer was completely desorbed and removed. Therefore, in the first regeneration step, the strong acid component in the WA layer is completely removed, and then the SA layer is regenerated, so that the regeneration waste liquid containing silica eluted from the SA layer in the regeneration of the SA layer Even if it passes, the pH of the regenerated waste liquid does not drop while passing through the WA layer, and silica gelation and precipitation do not occur.
  • Specific operation procedures of the regeneration step in the present invention include the following (1) to (6).
  • the regenerant After performing the first regeneration step in which the regenerant is passed through only the WA layer of (i), the regenerant is introduced into the tower from the SA layer side, and the regenerant is retained for a predetermined time by immersion regeneration. 2 Perform the regeneration process. In this case, if the multi-layered anion exchange tower is a single tower type, the regenerant is introduced into the tower from the SA layer side, and the entire SA layer and WA layer are immersed in the regenerator. If the multi-layer type anion exchange tower is a double tower type, only the SA layer can be dipped and regenerated. (5) After performing the first regeneration step of passing the regenerant in the order of SA layer ⁇ WA layer of (ii), the second regeneration step of passing the regenerant through the SA layer ⁇ WA layer is performed.
  • the second regeneration step by immersion regeneration holding the regenerant for a predetermined time is performed.
  • This regeneration step (ii) is usually employed when the multi-layered anion exchange column is of a single column type.
  • the SA layer is regenerated in the second regeneration step, it is preferable to use a regenerator that has been heated to 35 ° C. or more and 55 ° C. or less as described above. This is because if the regenerator is heated, NaOH can quickly diffuse into the resin and silica can be effectively eluted.
  • the regenerant used in the first regeneration step may be warmed or warmed, whether it is passed through the WA layer alone or from the SA layer to the WA layer. Or higher and lower than 35 ° C, preferably 20 ° C or higher and 30 ° C or lower).
  • the immersion temperature (the temperature of the regenerant retained in the tower in the immersion step) varies depending on the immersion time, but is usually 5 ° C. or more and 55 ° C. or less, preferably It is normal temperature (5 degreeC or more and less than 35 degreeC, Preferably it is 20 degreeC or more and 30 degrees C or less).
  • the time of the dipping process is usually 20 minutes or more, preferably about 30 to 120 minutes.
  • a regenerant at room temperature (5 ° C. or more and less than 35 ° C., preferably 20 ° C. or more and 30 ° C. or less) can be used by setting the immersion time to 30 minutes or more.
  • a regenerant at room temperature (5 ° C. or more and less than 35 ° C., preferably 20 ° C. or more and 30 ° C. or less) should be used. it can.
  • Silica is polymerized and adsorbed inside the SA resin, but immersion regeneration also has an effect of ensuring a reaction time for decomposing and eluting the polymer of silica.
  • “Silica elution rate” was defined as follows, and this was used as an index to evaluate regeneration efficiency. A silica elution rate of less than 100% indicates that silica gelation is occurring. The upper limit of the elution rate of silica is theoretically 100%, but in the case of a resin from which water has been repeatedly collected, there may be a case where the silica load remaining at the previous regeneration exceeds 100%.
  • Elution rate of silica (%) (total amount of silica in the regenerated waste liquid from the column / total amount of silica loading of feed water) ⁇ 100
  • Total amount of silica in reclaimed waste liquid average silica concentration in reclaimed waste liquid x amount of reclaimed waste liquid
  • Total amount of silica in feed water silica concentration in feed water x supply water flow rate x supply time
  • silica The analysis of silica was performed according to JIS and was as follows. Ionic silica: JIS 44.1.2 Molybdenum blue method All silica: JIS 44.3 Gel silica: (total silica analysis value according to JIS 44.3)-(ionic silica analysis value according to JIS 44.1.2)
  • the liquid flow through the column ( ⁇ 40 mm acrylic column) and water flow were performed under the following common conditions, the amount of resin according to the purpose, the feed water temperature, and the ion concentration.
  • regenerant flow Regenerant flow: Reverse direction of feed water flow
  • LV 10 m / hr
  • a NaOH aqueous solution was used as a regenerant, and the amount was determined so that the molar ratio was 110% with respect to the total amount of loaded ions in the feed water.
  • Example 1 One of the two columns was filled with SA so that the resin layer height was 500 mm, and the other was filled with WA so that the resin layer height was 500 mm.
  • This column is connected in series, and in the order of WA column ⁇ SA column, feed water with a chloride ion concentration of 80 mg / L and a silica concentration of 43 mg / L becomes 15 g-SiO 2 / LR (SA) per liter of resin. The water passed through.
  • the silica is discharged in an ionic state under a condition that exceeds pH 9, preferably pH 10, so that the effluent of the anion exchange tower is regenerated under a condition that exceeds pH 9, preferably pH 10, so that the WA layer It can be seen that the gelation of silica does not occur even if it flows into the.
  • Example 1 One of the two columns was filled with SA so that the resin layer height was 500 mm, and the other was filled with WA so that the resin layer height was 500 mm.
  • This column is connected in series, and in the order of WA column ⁇ SA column, feed water with a chloride ion concentration of 80 mg / L and a silica concentration of 43 mg / L becomes 15 g-SiO 2 / LR (SA) per liter of resin. The water passed through.
  • regenerant As the regenerant, a normal temperature (25 ° C.), NaOH aqueous solution having a NaOH concentration of 1% by weight was used. First, the regenerant was passed through only the WA column, and pre-regeneration was performed until the pH of the tower effluent reached 9. The tower effluent was discharged out of the system. Thereafter, the regenerant was heated (45 ° C.), and the regeneration was conducted by continuously passing the column effluent until the pH reached 14 in the order of the SA column ⁇ WA column, followed by extrusion with pure water alone.
  • Example 1 regeneration was performed by continuously passing in the order of the SA column ⁇ WA column without performing prior regeneration of the WA column, and then extrusion was performed only with pure water. After repeating the above-mentioned feed water flow and regeneration 5 times, the elution rate of the sixth silica was calculated and found to be 97%.
  • Example 1 From the results of Example 1 and Comparative Example 1, it can be seen that by performing the prior regeneration of the WA layer, it is possible to prevent silica gelation and efficiently elute the silica for regeneration.
  • Example 2 One of the two columns was filled with SA so that the resin layer height was 500 mm, and the other was filled with WA so that the resin layer height was 500 mm.
  • This column is connected in series, and in the order of WA column ⁇ SA column, feed water with a chloride ion concentration of 80 mg / L and a silica concentration of 43 mg / L becomes 15 g-SiO 2 / LR (SA) per liter of resin. The water passed through.
  • a NaOH aqueous solution having a NaOH concentration of 1% by weight was used as the regenerant, and the regenerant was added to each of the SA column and WA column so that the amount of ions loaded on each resin was 110%. Were individually passed until each became 14, and the tower effluent was discharged out of the system. Thereafter, extrusion with pure water alone was similarly performed. The regenerant was passed through the WA column at room temperature (25 ° C.) and through the SA column at warm (45 ° C.).
  • Example 2 From Example 2, it can be seen that by separately regenerating the SA layer and the WA layer, the silica can be prevented from gelation and efficiently regenerated by eluting the silica.
  • Example 3 Two columns were packed with SA so that the resin layer height was 500 mm. Through these two columns, feed water having a silica concentration of 43 mg / L was passed so as to be 15 g-SiO 2 / LR per liter of resin.
  • One column was regenerated by passing a NaOH aqueous solution (pH 14 or higher) having a temperature of 25 ° C. and a NaOH concentration of 1% by weight. After confirming that the pH of the tower effluent was 13, the solution was sealed for 30 minutes. . After passing a predetermined amount of the remaining NaOH aqueous solution after the immersion process for 30 minutes, extrusion with pure water alone was performed. After the feed water was passed and regenerated five times, the sixth elution rate of silica was calculated and found to be 103%.
  • the other column was passed through the entire amount of NaOH aqueous solution having a temperature of 25 ° C. and a NaOH concentration of 1% by weight, and then regenerated by extruding only with pure water.
  • the pH of the tower effluent during regeneration was 13. Thereafter, the elution rate of silica was calculated to be 85%.
  • the silica can be efficiently eluted from SA even by a NaOH aqueous solution at room temperature by performing the dipping process.

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Abstract

A method for regenerating a weakly basic anion exchange resin and a strongly basic anion exchange resin by passing a regeneration agent through a multilayer anion exchange column provided with a weakly basic anion exchange resin layer and a strongly basic anion exchange resin layer in which water to be processed was passed in sequence from the weakly basic anion exchange resin layer to the strongly basic anion exchange resin layer, wherein a first regeneration step is performed in which the regeneration agent is passed only through the weakly basic anion exchange resin layer, or is passed in sequence from the strongly basic anion exchange resin layer to the weakly basic anion exchange resin layer, and then a second regeneration step is performed in which the strongly basic anion exchange resin layer is regenerated, whereby gelatinization of the silica is suppressed and regeneration is performed efficiently.

Description

複層式陰イオン交換塔の再生方法Regeneration method of multi-layer anion exchange tower
　本発明は、弱塩基性陰イオン交換樹脂層と強塩基性陰イオン交換樹脂層を備え、被処理水が弱塩基性陰イオン交換樹脂層から強塩基性陰イオン交換樹脂層の順に通水された複層式陰イオン交換塔の再生方法に関する。 The present invention comprises a weakly basic anion exchange resin layer and a strongly basic anion exchange resin layer, and the water to be treated is passed through the weakly basic anion exchange resin layer to the strongly basic anion exchange resin layer in this order. The present invention also relates to a method for regenerating a multilayer anion exchange column.
　純水等の製造を目的として使用される陰イオン交換樹脂は、一部の強酸成分とシリカ、ホウ素、炭酸などの弱酸成分を吸着除去するための強塩基性陰イオン交換樹脂（以下「ＳＡ」と略記する場合がある。）と、硫酸イオン、塩化物イオンなどの強酸成分を吸着除去するための弱塩基性陰イオン交換樹脂（以下「ＷＡ」と略記する場合がある。）の２種類に大別される。 Anion exchange resins used for the production of pure water and the like are strongly basic anion exchange resins (hereinafter "SA") for adsorbing and removing some strong acid components and weak acid components such as silica, boron and carbonic acid. And a weakly basic anion exchange resin (hereinafter sometimes abbreviated as “WA”) for adsorbing and removing strong acid components such as sulfate ions and chloride ions. Broadly divided.
　ＳＡとＷＡは、構造中のイオン交換基の性質により吸着したイオンの保持力が異なり、ＳＡは保持力が強く、ＷＡは保持力が弱い。 SA and WA have different holding powers for ions adsorbed depending on the nature of the ion exchange group in the structure, SA has a strong holding power, and WA has a low holding power.
　陰イオン交換塔としては、ＳＡのみを備えた塔を使用する単層式と、ＷＡとＳＡの両方の樹脂を備えた塔を使用する複層式とがある。複層式の陰イオン交換塔は、被処理水（通常の場合、陽イオン交換塔に通水された後の処理水）を、まずＷＡ層に通水し、その後にＳＡ層に通水する装置である。 As anion exchange towers, there are a single-layer system using a tower equipped with only SA and a multi-layer system using a tower equipped with both WA and SA resins. In the multi-layer anion exchange tower, treated water (usually treated water after passing through the cation exchange tower) first passes through the WA layer, and then passes through the SA layer. Device.
　複層式陰イオン交換塔としては、ＷＡとＳＡとをそれぞれ別々の塔に充填した２塔式と、同じ一つの塔に、ＷＡとＳＡとが層状になるように充填した１塔式とがある。１塔式の場合、通常、ＷＡ層とＳＡ層とは、透水性の仕切り板で仕切られる。 As the multi-layer type anion exchange tower, there are a two-column system in which WA and SA are packed in separate towers, and a single-column system in which the same tower is packed so that WA and SA are layered. is there. In the case of a single tower type, the WA layer and the SA layer are usually partitioned by a water-permeable partition plate.
　複層式陰イオン交換塔で純水を採水した後は、再生が行われる。ＳＡ層にはシリカ、ホウ素、炭酸などの弱酸成分と、ＷＡ層で吸着されずに一部ＷＡ層から漏洩した強酸成分が吸着している。ＷＡ層には強酸負荷の殆どが吸着している。 After collecting pure water in the multi-layer anion exchange tower, regeneration is performed. The SA layer is adsorbed with weak acid components such as silica, boron, and carbonic acid, and strong acid components that are not adsorbed by the WA layer but partially leaked from the WA layer. Most of the strong acid load is adsorbed on the WA layer.
　複層式陰イオン交換塔は通常、ＳＡ層→ＷＡ層の順に再生剤である水酸化ナトリウム（ＮａＯＨ）水溶液を通水して再生される。これは次の理由による。 The multi-layer anion exchange tower is usually regenerated by passing a sodium hydroxide (NaOH) aqueous solution as a regenerant in the order of SA layer → WA layer. This is due to the following reason.
　ＳＡとＷＡとでは吸着したイオンの保持力が異なるが、この保持力の強弱から再生効率が異なる。保持力の弱いＷＡは少ない再生剤量で再生されるため、ＳＡ層→ＷＡ層の順に再生剤を通水して、ＳＡ層で使用されなかった再生剤をＷＡ層で使用する。 SA and WA have different retention of adsorbed ions, but the regeneration efficiency differs depending on the strength of this retention. Since WA with weak holding power is regenerated with a small amount of regenerant, the regenerant is passed through in the order of SA layer → WA layer, and the regenerant that was not used in the SA layer is used in the WA layer.
　ＳＡを再生する際は、樹脂に吸着しているシリカの脱離率を高めるために、４０～５０℃に加温された再生剤を使用することが多い。ＳＡ層の再生廃液は高濃度のシリカを含むことになる。しかし、シリカを高濃度で含む再生廃液を使ってＷＡ層を再生すると、ＷＡ層内でシリカのゲル化が発生する（非特許文献１）。これは、ＷＡが再生されると、吸着していた強酸成分を脱離することにより、再生液のｐＨが急激に低下して、シリカの溶解度が低下するためである。 When regenerating SA, a regenerant heated to 40 to 50 ° C. is often used to increase the desorption rate of silica adsorbed on the resin. The regeneration waste liquid of the SA layer contains a high concentration of silica. However, when the WA layer is regenerated using a regeneration waste liquid containing silica at a high concentration, gelation of silica occurs in the WA layer (Non-patent Document 1). This is because when the WA is regenerated, the strong acid component that has been adsorbed is desorbed, whereby the pH of the regenerated solution is drastically lowered and the solubility of silica is lowered.
　シリカのゲル化を防ぐ方法として、再生中に再生剤の水酸化ナトリウム濃度を調整して、脱離するシリカ濃度を変化させる方法がある（特許文献１）。しかし、この方法では、１％の低濃度ＮａＯＨ水溶液であっても、７．５ｇ－ＳｉＯ２／Ｌ程度のシリカ溶解度であるため、ＷＡで脱離する酸が多ければ結果的にｐＨが急激に低下してシリカがゲル化することとなる。 As a method for preventing gelation of silica, there is a method in which the concentration of desorbed silica is changed by adjusting the sodium hydroxide concentration of the regenerant during regeneration (Patent Document 1). However, this method has a silica solubility of about 7.5 g-SiO 2 / L even in a 1% low-concentration NaOH aqueous solution. The silica is gelled by lowering.
　再生剤の温度を低温から段階的に上げていくことで、脱離するシリカ濃度を変化させる方法も知られている。この方法ではシリカの濃度を低減できても、ＷＡ層で強酸の脱離を制御することはできず、ゲル化を起こすことに変わりはない。また、温度変化させるタイミングが明確ではなく、タイミングが遅ければ再生不十分となって潜在的に再生不良を招くリスクもある。さらに、再生に用いる純水の使用量が多くなり経済的ではない。 Also known is a method of changing the concentration of desorbed silica by gradually increasing the temperature of the regenerant from a low temperature. In this method, even if the concentration of silica can be reduced, the elimination of strong acid cannot be controlled in the WA layer, and gelation remains unchanged. In addition, the timing for changing the temperature is not clear, and if the timing is late, there is a risk that the reproduction is insufficient and potentially a reproduction failure is caused. Furthermore, the amount of pure water used for regeneration increases, which is not economical.
特公昭４６－３３９２６号公報Japanese Patent Publication No.46-33926 特許第３１５０８３６号公報Japanese Patent No. 3150836
　本発明は、複層式陰イオン交換塔を再生する際のシリカのゲル化を抑制して、効率的な再生を行うことを目的とする。 An object of the present invention is to suppress the gelation of silica at the time of regenerating a multi-layered anion exchange column and to perform efficient regeneration.
　本発明者は、所定の第１再生工程と第２再生工程とを行うことにより、ＷＡ層におけるシリカのゲル化を防止することができることを見出した。
　本発明は、以下を要旨とする。 The present inventor has found that the gelation of silica in the WA layer can be prevented by performing the predetermined first regeneration step and second regeneration step.
The gist of the present invention is as follows.
［１］　弱塩基性陰イオン交換樹脂層と強塩基性陰イオン交換樹脂層を備え、被処理水が弱塩基性陰イオン交換樹脂層から強塩基性陰イオン交換樹脂層の順に通水された複層式陰イオン交換塔に再生剤を通液して該弱塩基性陰イオン交換樹脂及び強塩基性陰イオン交換樹脂を再生する方法において、(i)再生剤を、該複層式陰イオン交換塔の弱塩基性陰イオン交換樹脂層と強塩基陰イオン交換樹脂層との間から導入し、弱塩基性陰イオン交換樹脂層を通過させて該塔から流出させる工程、もしくは(ii)再生剤を、該複層式陰イオン交換塔の強塩基性陰イオン交換樹脂層側から導入して強塩基性陰イオン交換樹脂層から弱塩基性陰イオン交換樹脂層の順に通過させて該塔から流出させる工程を、塔流出液のｐＨがアルカリ性になるまで継続する第１再生工程と、該第１再生工程後に該強塩基性陰イオン交換樹脂層を再生する第２再生工程とを行うことを特徴とする複層式陰イオン交換塔の再生方法。 [1] A weakly basic anion exchange resin layer and a strongly basic anion exchange resin layer are provided, and water to be treated is passed through the weakly basic anion exchange resin layer and the strong base anion exchange resin layer in this order. In a method for regenerating the weakly basic anion exchange resin and the strongly basic anion exchange resin by passing a regenerant through a multilayer anion exchange column, (i) the regenerant is the multilayer anion. Introducing from between the weakly basic anion exchange resin layer and the strong base anion exchange resin layer of the exchange tower, passing through the weak base anion exchange resin layer and flowing out of the tower, or (ii) regeneration The agent is introduced from the strong base anion exchange resin layer side of the multilayer anion exchange column and passed through the strong base anion exchange resin layer to the weak base anion exchange resin layer in this order. Continue the effluent process until the pH of the tower effluent becomes alkaline. A regeneration method for a multilayer anion exchange column, comprising performing a regeneration step and a second regeneration step of regenerating the strongly basic anion exchange resin layer after the first regeneration step.
［２］　［１］において、前記第１再生工程を、前塔流出液のｐＨが９以上となるまで行うことを特徴とする複層式陰イオン交換塔の再生方法。 [2] A method for regenerating a multi-layered anion exchange column according to [1], wherein the first regeneration step is performed until the pH of the front tower effluent becomes 9 or more.
［３］　［１］又は［２］において、前記第２再生工程において、前記強塩基性陰イオン交換樹脂層に加温した再生剤を通液することを特徴とする複層式陰イオン交換塔の再生方法。 [3] The multilayer anion exchange tower according to [1] or [2], wherein in the second regeneration step, a warming regenerant is passed through the strongly basic anion exchange resin layer. How to play.
［４］　［１］又は［２］において、前記第２再生工程において、前記強塩基性陰イオン交換樹脂層を常温の再生剤に所定時間浸漬させることを特徴とする複層式陰イオン交換塔の再生方法。 [4] The multilayer anion exchange tower according to [1] or [2], wherein the strongly basic anion exchange resin layer is immersed in a regenerant at room temperature for a predetermined time in the second regeneration step. How to play.
［５］　［１］又は［２］において、前記第１再生工程において、前記(i)の工程を行い、その後、前記第２再生工程において、再生剤を、前記複層式陰イオン交換塔の強塩基性陰イオン交換樹脂層側から導入して強塩基性陰イオン交換樹脂層から弱塩基性陰イオン交換樹脂層の順に通過させて該塔から流出させることにより、前記強塩基性陰イオン交換樹脂層を再生することを特徴とする複層式陰イオン交換塔の再生方法。 [5] In [1] or [2], in the first regeneration step, the step (i) is performed, and then in the second regeneration step, the regenerant is added to the multilayer anion exchange column. The strong basic anion exchange resin layer is introduced from the strong basic anion exchange resin layer side and then passed through the strong basic anion exchange resin layer in the order of the weak basic anion exchange resin layer to flow out of the tower, thereby the strong basic anion exchange. A method for regenerating a multi-layered anion exchange tower, wherein the resin layer is regenerated.
［６］　弱塩基性陰イオン交換樹脂層と強塩基性陰イオン交換樹脂層を備え、被処理水が弱塩基性陰イオン交換樹脂層から強塩基性陰イオン交換樹脂層の順に通水された複層式陰イオン交換塔に再生剤を通液して該弱塩基性陰イオン交換樹脂及び強塩基性陰イオン交換樹脂を再生する方法において、(i)再生剤を、該複層式陰イオン交換塔の弱塩基性陰イオン交換樹脂層と強塩基陰イオン交換樹脂層との間から導入し、弱塩基性陰イオン交換樹脂層を通過させて該塔から流出させる工程を、塔流出液のｐＨがアルカリ性になるまで継続する第１再生工程と、該強塩基性陰イオン交換樹脂層を再生する第２再生工程とを行う複層式陰イオン交換塔の再生方法であって、該１再生工程と該第２再生工程とを同時に行い、該第２再生工程において、該強塩基性陰イオン交換樹脂層の再生に用いた再生剤を該弱塩基性陰イオン交換樹脂層を通過させることなく、該複層式陰イオン交換塔外へ排出することを特徴とする複層式陰イオン交換塔の再生方法。 [6] A weakly basic anion exchange resin layer and a strongly basic anion exchange resin layer are provided, and water to be treated is passed through the weakly basic anion exchange resin layer to the strong base anion exchange resin layer in this order. In a method for regenerating the weakly basic anion exchange resin and the strongly basic anion exchange resin by passing a regenerant through a multilayer anion exchange column, (i) the regenerant is the multilayer anion. The step of introducing from between the weakly basic anion exchange resin layer and the strong base anion exchange resin layer of the exchange tower, passing through the weakly basic anion exchange resin layer and flowing out of the tower, A regeneration method for a multi-layered anion exchange column, comprising a first regeneration step that continues until the pH becomes alkaline and a second regeneration step that regenerates the strongly basic anion exchange resin layer, Performing the step and the second regeneration step at the same time, in the second regeneration step, A multi-layer system wherein the regenerant used for regenerating the basic anion exchange resin layer is discharged out of the multi-layer anion exchange tower without passing through the weak base anion exchange resin layer. Regeneration method of anion exchange tower.
［７］　［１］ないし［６］のいずれかにおいて、前記再生剤を通液する複層式陰イオン交換塔中の前記強塩基性陰イオン交換樹脂はシリカを吸着、保持しており、前記弱塩基性陰イオン交換樹脂は強酸を吸着、保持していることを特徴とする複層式陰イオン交換塔の再生方法。 [7] In any one of [1] to [6], the strongly basic anion exchange resin in the multilayer anion exchange tower through which the regenerant is passed adsorbs and holds silica, A method for regenerating a multilayer anion exchange column, wherein a weakly basic anion exchange resin adsorbs and retains a strong acid.
［８］　［１］ないし［７］のいずれかにおいて、前記第１の再生工程に先立つ、被処理水通水時の温度を５～２０℃の範囲に維持することを特徴とする複層式陰イオン交換塔の再生方法。 [8] In any one of [1] to [7], the temperature at the time of passing the water to be treated is maintained in the range of 5 to 20 ° C. prior to the first regeneration step. Regeneration method of anion exchange tower.
　本発明によれば、複層式陰イオン交換塔を再生する際のシリカのゲル化を抑制して、効率的な再生を行うことができる。 According to the present invention, it is possible to suppress the gelation of silica at the time of regenerating the multi-layered anion exchange tower and perform efficient regeneration.
Ｆｉｇ．１は、実験例１における再生廃液のＣｌイオン濃度、イオン状シリカ濃度、コロイダルシリカ濃度及びｐＨの経時変化を示すグラフである。FIG. 1 is a graph showing changes over time in the Cl ion concentration, ionic silica concentration, colloidal silica concentration, and pH of the regenerated waste liquid in Experimental Example 1.
　以下に本発明の実施の形態を詳細に説明する。 Hereinafter, embodiments of the present invention will be described in detail.
［複層式陰イオン交換塔］
　本発明において、再生を行う複層式陰イオン交換塔は、弱塩基性陰イオン交換樹脂（ＷＡ）層と強塩基性陰イオン交換樹脂（ＳＡ）層とを備えるものである。複層式陰イオン交換塔はＷＡ層とＳＡ層とが１つの塔内に設けられた１塔式であってもよい。複層式陰イオン交換塔はＷＡとＳＡとがそれぞれ別の塔に充填された２塔式であってもよい。 [Multi-layer anion exchange tower]
In the present invention, a multilayer anion exchange tower for regeneration comprises a weakly basic anion exchange resin (WA) layer and a strongly basic anion exchange resin (SA) layer. The multi-layered anion exchange tower may be a single tower type in which the WA layer and the SA layer are provided in one tower. The multi-layered anion exchange column may be a two-column type in which WA and SA are packed in separate columns.
　複層式陰イオン交換塔に被処理水を通水して採水する場合、被処理水はＷＡ層からＳＡ層の順で通水される。 When collecting the water to be treated by passing it through the multi-layer anion exchange tower, the water to be treated is passed in the order from the WA layer to the SA layer.
　本発明においては、被処理水を通水することで、ＷＡ層に強酸成分が吸着、保持され、ＳＡ層にシリカ、ホウ素、炭酸などの弱酸成分と、ＷＡ層で除去し得ずにＳＡ層に流入した強酸成分とを吸着、保持した複層式陰イオン交換塔の再生を行う。 In the present invention, by passing water to be treated, strong acid components are adsorbed and retained in the WA layer, and weak acid components such as silica, boron, carbonic acid, etc., and the SA layer cannot be removed by the WA layer. The multi-layer anion exchange tower that adsorbs and holds the strong acid component that has flowed into the column is regenerated.
　複層式陰イオン交換塔は、後述の第１再生工程と第２再生工程からなる再生工程で再生され、再生工程後は、再生剤の通液方向と同じ方向に純水を通液する押出し洗浄工程が実施される。押出し洗浄は、押出し洗浄時の塔流出液のｐＨが１０～１２程度になるまで行われる。必要に応じて、押出し洗浄工程後は、塔流出液の純度を上げて採水を開始するために、被処理水や純水を採水時の通水方向と同じ方向に流して洗浄したり、洗浄廃液を少なくする目的で、塔流出液を陽イオン交換塔及び脱炭酸塔で処理した後循環、通液させたりして、所望の純度の塔流出液が得られるようになった時点で再生のための一連の処理を終了し、採水、即ち、純水の製造を再開する。 The multi-layer anion exchange tower is regenerated in a regeneration step consisting of a first regeneration step and a second regeneration step, which will be described later. A cleaning step is performed. Extrusion washing is performed until the pH of the column effluent during extrusion washing reaches about 10-12. If necessary, after the extrusion washing process, in order to increase the purity of the tower effluent and start sampling, the water to be treated and pure water are washed in the same direction as the water flow direction during sampling. For the purpose of reducing washing waste liquid, the tower effluent is treated with a cation exchange tower and a decarboxylation tower, and then circulated and passed to obtain a tower effluent with a desired purity. A series of processes for regeneration is completed, and water sampling, that is, production of pure water is resumed.
　複層式陰イオン交換塔の再生を行うに先立ち、採水時に被処理水を５～２０℃、好ましくは５～１５℃の低温にして複層式陰イオン交換塔に通水して複層式陰イオン交換塔内をこのような低温に維持する工程を行うことが好ましい。これは、以下の理由による。 Prior to regeneration of the multi-layer anion exchange tower, the water to be treated is cooled to 5 to 20 ° C., preferably 5 to 15 ° C. at the time of sampling, and the multi-layer anion exchange tower is passed through the multi-layer anion exchange tower. It is preferable to carry out the step of maintaining the inside of the formula anion exchange column at such a low temperature. This is due to the following reason.
　ＳＡに吸着したシリカは温度が高いほど重合し易いため、採水工程をこのような低温で行うことにより、複層式陰イオン交換塔内でのシリカの重合を抑制し、再生工程におけるシリカの脱離性を高めて効率的な再生を行えるようになる。このため、被処理水の温度が高い場合には、被処理水の温度を上記範囲に下げた上で、複層式陰イオン交換塔に通水することが好ましい。 Since the silica adsorbed on SA is more easily polymerized at higher temperatures, the water sampling step is performed at such a low temperature to suppress the polymerization of silica in the multi-layer anion exchange tower, and the silica in the regeneration step Increases detachability and enables efficient regeneration. For this reason, when the temperature of to-be-processed water is high, it is preferable to lower the temperature of to-be-processed water to the said range, and to flow through a multilayer anion exchange tower.
［再生工程］
＜再生剤＞
　ＷＡ及びＳＡの再生には、再生剤として水酸化ナトリウム（ＮａＯＨ）水溶液が使用される。 [Regeneration process]
<Regenerant>
For the regeneration of WA and SA, an aqueous solution of sodium hydroxide (NaOH) is used as a regenerant.
　再生剤であるＮａＯＨ水溶液は、再生効率の面から、ＮａＯＨ濃度０．５～５．０重量％（通常ｐＨ１３以上）であることが好ましい。ＮａＯＨ濃度が上記下限よりも低いと、再生剤として、選択係数の小さいＯＨイオンで選択係数の大きいイオンを交換するので非効率である。ＮａＯＨ濃度が上記上限より高いと、樹脂内部への浸透の観点で速度が上がらないために、非効率である。 It is preferable that the NaOH aqueous solution as the regenerant has a NaOH concentration of 0.5 to 5.0% by weight (usually pH 13 or more) from the viewpoint of regeneration efficiency. If the NaOH concentration is lower than the lower limit, it is inefficient because ions having a large selection coefficient are exchanged with OH ions having a small selection coefficient as a regenerant. When the NaOH concentration is higher than the above upper limit, the speed does not increase from the viewpoint of penetration into the resin, which is inefficient.
＜通液方向＞
　再生剤を通液する際の通液方向には特に制限はないが、被処理水の通水方向（採水時の通水方向）と逆方向とすることが好ましい。 <Flow direction>
Although there is no restriction | limiting in particular in the liquid flow direction at the time of flowing a regenerant, It is preferable to set it as the reverse direction to the water flow direction (water flow direction at the time of sampling) of to-be-processed water.
　通常の場合、採水時の通水方向は下向流である場合が多く、従って、再生時の通液方向は上向流とすることが好ましい。前述の押出し洗浄時の通液方向についても、再生剤の通液方向と同様とすることが好ましい。 In normal cases, the water flow direction during sampling is often a downward flow, and therefore the liquid flow direction during regeneration is preferably an upward flow. The liquid passing direction at the time of the above-described extrusion cleaning is preferably the same as the flow direction of the regenerant.
＜温度＞
　再生剤の温度は次の通りである。 <Temperature>
The temperature of the regenerant is as follows.
　ＷＡ層のみに通液される再生剤の温度は、常温から加温された範囲である５℃以上５５℃以下でよく、通常は常温である５℃以上３５℃未満（寒冷地や夏季の水温）、好ましくは２０℃以上３０℃以下である。 The temperature of the regenerant that is passed through only the WA layer may be 5 ° C. or more and 55 ° C. or less, which is a range heated from room temperature, and is usually 5 ° C. or more and less than 35 ° C. (water temperature in cold regions or summer). ), Preferably 20 ° C. or higher and 30 ° C. or lower.
　ＳＡ層のみに通液される再生剤の温度は、常温から加温された範囲である５℃以上５５℃以下でよく、通常は加温された３５℃以上５５℃以下が好ましく、４０℃以上４５℃以下がもっとも好ましい。 The temperature of the regenerant that is passed through only the SA layer may be 5 ° C. or higher and 55 ° C. or lower, which is a range warmed from normal temperature, and is usually 35 ° C. or higher and 55 ° C. or lower, preferably 40 ° C. or higher. Most preferred is 45 ° C or lower.
　ＳＡ層からＷＡ層に連続して通液される再生剤は、５℃以上５５℃以下とすることが好ましい。 The regenerant that is continuously passed from the SA layer to the WA layer is preferably 5 ° C. or higher and 55 ° C. or lower.
　但し、ＳＡ層に対して後述の浸漬工程を行う場合、浸漬時間を３０分以上とすることで、常温（５℃以上３５℃未満、好ましくは２０℃以上３０℃以下）の再生剤を用いることができる。 However, when the immersion process described below is performed on the SA layer, a regenerant at room temperature (5 ° C. or more and less than 35 ° C., preferably 20 ° C. or more and 30 ° C. or less) is used by setting the immersion time to 30 minutes or more. Can do.
＜通液量＞
　再生剤の通液量は、再生する複層式陰イオン交換塔の負荷、或いは塔流出液（再生廃液）のｐＨに基づき、次のような量とすることが好ましい。 <Flow rate>
The flow rate of the regenerant is preferably set to the following amount based on the load of the multilayer anion exchange tower to be regenerated or the pH of the tower effluent (regeneration waste liquid).
　再生剤の通液量は、再生する複層式陰イオン交換塔の設計負荷（脱着するイオン量）に対して通液されたＮａＯＨのモル比が１００％以上、好ましくは１１０～１３５％となる量とすることが好ましい。 The flow rate of the regenerant is such that the molar ratio of NaOH passed is 100% or more, preferably 110 to 135% with respect to the design load (the amount of ions to be desorbed) of the regenerative multilayer anion exchange column. It is preferable to use an amount.
　この設計負荷に対するＮａＯＨモル比は、ＷＡ層とＳＡ層との全体の設計負荷に対して設定してもよく、各層個別の設計負荷に対して設定してもよい。また、実際の運用負荷を分析し、この値に対して設定してもよい。 The NaOH molar ratio with respect to the design load may be set for the overall design load of the WA layer and the SA layer, or may be set for the design load of each layer individually. Also, the actual operational load may be analyzed and set for this value.
　再生剤の通液量は、ＳＡ層のみの通液の場合は、ＳＡ層のみを通過した塔流出液（再生廃液）のｐＨが９以上、好ましくは１０以上、より好ましくは１３以上となるような量とすることが好ましい。 When the regenerant is passed through only the SA layer, the pH of the column effluent (regeneration waste liquid) that has passed through the SA layer is 9 or higher, preferably 10 or higher, more preferably 13 or higher. It is preferable to make it an amount.
　ＷＡ層のみの通水の場合は、ＷＡ層のみを通過した塔流出液（再生廃液）のｐＨが９以上、好ましくは１０以上、より好ましくは１３以上となるような量とすることが好ましい。 In the case of passing only water through the WA layer, the amount of the tower effluent (regenerated waste liquid) that has passed through the WA layer is preferably 9 or more, preferably 10 or more, more preferably 13 or more.
　ＳＡ層とＷＡ層とに連続して再生剤を通水する場合は、ＳＡ層→ＷＡ層の順で通過してＷＡ層側から排出される塔流出液（ＷＡ層から排出される再生廃液）のｐＨが９以上、好ましくは１０～１３となるような量とすることが好ましい。 When the regenerant is continuously passed through the SA layer and the WA layer, the tower effluent discharged from the WA layer side in the order of the SA layer → WA layer (recycled waste liquid discharged from the WA layer) It is preferable to adjust the pH to 9 or more, preferably 10 to 13.
＜浸漬工程＞
　再生剤の通液後、通液を停止して所定時間そのまま保持する浸漬工程を行ってもよい。 <Immersion process>
After passing the regenerant, a dipping step may be performed in which the passing is stopped and held for a predetermined time.
　この場合、浸漬を開始するタイミングは、再生剤の通液量が前述の量となった時点とすることが好ましい。 In this case, it is preferable that the timing of starting the immersion is the time when the flow rate of the regenerant reaches the aforementioned amount.
　浸漬温度（浸漬工程において塔内に保持される再生剤の温度）は、浸漬時間によっても異なるが、通常５℃以上５５℃以下、好ましくは常温（５℃以上３５℃未満、好ましくは２０℃以上３０℃以下）である。 The immersion temperature (the temperature of the regenerant held in the tower in the immersion step) varies depending on the immersion time, but is usually 5 ° C. or higher and 55 ° C. or lower, preferably normal temperature (5 ° C. or higher and lower than 35 ° C., preferably 20 ° C. or higher). 30 ° C. or lower).
　浸漬工程は通常２０分以上、好ましくは３０～１２０分程度である。 The dipping process is usually 20 minutes or more, preferably about 30 to 120 minutes.
　上記の温度と時間の範囲で、浸漬温度が高い場合には、浸漬時間を短く、浸漬温度が低い場合は浸漬時間を長くすることが好ましい。 In the above temperature and time range, when the immersion temperature is high, it is preferable to shorten the immersion time, and when the immersion temperature is low, it is preferable to increase the immersion time.
　浸漬工程を行うことで、ＳＡに吸着しているシリカ等や、ＷＡに吸着している強酸成分の脱着を促進させることができる。 By performing the dipping process, it is possible to promote the desorption of silica or the like adsorbed on SA and the strong acid component adsorbed on WA.
＜再生操作＞
　以下に、本発明における具体的な再生操作について説明する。 <Playback operation>
Hereinafter, a specific reproduction operation in the present invention will be described.
　本発明においては、(i)再生剤を、複層式陰イオン交換塔のＷＡ層とＳＡ層との間から導入し、ＷＡ層のみを通過させて流出させる工程、もしくは(ii)再生剤を、複層式陰イオン交換塔のＳＡ層側から導入してＳＡ層からＷＡ層の順に通過させて流出させる工程を、塔流出液のｐＨがアルカリ性、好ましくはｐＨ９以上、より好ましくはｐＨ１０以上になるまで継続する第１再生工程を行い、この第１再生工程後にＳＡ層を再生する第２再生工程とを行う。 In the present invention, (i) a step of introducing the regenerant from between the WA layer and the SA layer of the multi-layered anion exchange tower and allowing only the WA layer to pass through, or (ii) a regenerant The step of introducing from the SA layer side of the multi-layered anion exchange tower and passing it through the SA layer to the WA layer in order is carried out, and the pH of the tower effluent is alkaline, preferably pH 9 or higher, more preferably pH 10 or higher. A first regeneration process that continues until the first regeneration process is performed, and a second regeneration process for regenerating the SA layer is performed after the first regeneration process.
　第２再生工程でＳＡ層を再生する方法としては、次のような方法が挙げられる。
(2-i)　再生剤を複層式陰イオン交換塔のＷＡ層とＳＡ層との間から導入し、ＳＡ層のみを通過させて塔のＳＡ層側から流出させる、或いは、再生剤を複層式陰イオン交換塔のＳＡ層側から導入し、塔のＳＡ層とＷＡ層との間から流出させる。
(2-ii)　再生剤を複層式陰イオン交換塔のＳＡ層側から導入してＳＡ層からＷＡ層の順に通過させて塔のＷＡ層側から流出させる。
(2-iii)　再生剤を複層式陰イオン交換塔のＳＡ層側から導入してＳＡ層の浸漬再生を行う。 Examples of the method for regenerating the SA layer in the second regeneration step include the following methods.
(2-i) The regenerant is introduced from between the WA layer and the SA layer of the multi-layer anion exchange tower, and only the SA layer is allowed to flow out from the SA layer side of the tower, or the regenerant is mixed. It introduce | transduces from the SA layer side of a layer type anion exchange column, and it is made to flow out between between the SA layer and WA layer of a column.
(2-ii) A regenerant is introduced from the SA layer side of the multi-layered anion exchange tower, passed from the SA layer to the WA layer in this order, and discharged from the WA layer side of the tower.
(2-iii) A regenerant is introduced from the SA layer side of the multi-layered anion exchange column to perform immersion regeneration of the SA layer.
　上記(2-i)のように、ＳＡ層のみに再生剤を通液してＳＡ層の再生に用いた再生剤をＷＡ層を通過させることなく塔外へ排出する場合、第１再生工程として、前記(i)の工程を採用することで、第１再生工程と第２再生工程とを同時に行うことができる。 As in (2-i) above, when the regenerant is passed through only the SA layer and the regenerant used for regenerating the SA layer is discharged outside the tower without passing through the WA layer, the first regeneration step By adopting the step (i), the first regeneration step and the second regeneration step can be performed simultaneously.
　このようなＳＡ層のみの再生、ＷＡ層のみの再生は、ＷＡ層とＳＡ層との間に再生剤の導入配管や再生廃液の排出配管を設けた複層式陰イオン交換塔を用いて行うことができる。 Such regeneration of only the SA layer and regeneration of only the WA layer are performed using a multi-layer anion exchange tower provided with a regenerant introduction pipe and a regeneration waste liquid discharge pipe between the WA layer and the SA layer. be able to.
　本発明では、第１再生工程で、塔流出液のｐＨがアルカリ性、好ましくはｐＨ９以上、より好ましくはｐＨ１０以上となるまで再生剤を通液し、その後、ＳＡ層の再生を行うことで、ＷＡ層におけるシリカのゲル化を防止することができる。これは次の理由による。 In the present invention, in the first regeneration step, the regenerant is passed through until the pH of the column effluent becomes alkaline, preferably pH 9 or more, more preferably pH 10 or more, and then the SA layer is regenerated, so that WA Silica gelation in the layer can be prevented. This is due to the following reason.
　 (i)の工程であっても、(ii)の工程であっても、ＷＡ層を通過した塔流出液のｐＨがアルカリ性、好ましくはｐＨ９以上、より好ましくはｐＨ１０以上であるということは、ＷＡ層に吸着していた強酸成分が完全に脱離除去されたことを意味する。このため、第１再生工程で、ＷＡ層の強酸成分を完全に除去した後、ＳＡ層の再生を行うことで、ＳＡ層の再生でＳＡ層から溶出したシリカを含む再生廃液が、ＷＡ層を通過したとしても、再生廃液のｐＨがＷＡ層の通過中で下がることはなく、シリカのゲル化、析出が起こることはない。 Whether in step (i) or (ii), the pH of the column effluent that has passed through the WA layer is alkaline, preferably pH 9 or higher, more preferably pH 10 or higher. It means that the strong acid component adsorbed on the layer was completely desorbed and removed. Therefore, in the first regeneration step, the strong acid component in the WA layer is completely removed, and then the SA layer is regenerated, so that the regeneration waste liquid containing silica eluted from the SA layer in the regeneration of the SA layer Even if it passes, the pH of the regenerated waste liquid does not drop while passing through the WA layer, and silica gelation and precipitation do not occur.
　本発明における具体的な再生工程の操作手順としては、以下の（１）～（６）が挙げられる。
（１）　(i)のＷＡ層のみに再生剤を通液する第１再生工程を行った後、ＳＡ層のみに再生剤を通液する第２再生工程を行う。
（２）　(i)のＷＡ層のみに再生剤を通液する第１再生工程と、ＳＡ層のみに再生剤を通液する第２再生工程を同時に行う。
（３）　(i)のＷＡ層のみに再生剤を通液する第１再生工程を行った後、ＳＡ層→ＷＡ層に再生剤を通液する第２再生工程を行う。
（４）　(i)のＷＡ層のみに再生剤を通液する第１再生工程を行った後、ＳＡ層側から再生剤を塔内に導入して所定時間再生剤を保持する浸漬再生による第２再生工程を行う。この場合、複層式陰イオン交換塔が１塔式であれば、再生剤をＳＡ層側から塔内に導入してＳＡ層及びＷＡ層の全体が再生剤に浸漬される。複層式陰イオン交換塔が２塔式であれば、ＳＡ層のみの浸漬再生を行える。
（５）　(ii)のＳＡ層→ＷＡ層の順で再生剤を通液する第１再生工程を行った後、ＳＡ層→ＷＡ層に再生剤を通液する第２再生工程を行う。
（６）　(ii)のＳＡ層→ＷＡ層の順で再生剤を通液する第１再生工程を行った後、所定時間再生剤を保持する浸漬再生による第２再生工程を行う。この(ii)の再生工程は、通常、複層式陰イオン交換塔が１塔式の場合に採用される。 Specific operation procedures of the regeneration step in the present invention include the following (1) to (6).
(1) After performing the first regeneration step of passing the regenerant through only the WA layer of (i), the second regeneration step of passing the regenerant through only the SA layer is performed.
(2) The first regeneration step in which the regenerant is passed through only the WA layer of (i) and the second regeneration step in which the regenerant is passed through only the SA layer are simultaneously performed.
(3) After performing the first regeneration step of passing the regenerant through only the WA layer of (i), the second regeneration step of passing the regenerator through the SA layer to the WA layer is performed.
(4) After performing the first regeneration step in which the regenerant is passed through only the WA layer of (i), the regenerant is introduced into the tower from the SA layer side, and the regenerant is retained for a predetermined time by immersion regeneration. 2 Perform the regeneration process. In this case, if the multi-layered anion exchange tower is a single tower type, the regenerant is introduced into the tower from the SA layer side, and the entire SA layer and WA layer are immersed in the regenerator. If the multi-layer type anion exchange tower is a double tower type, only the SA layer can be dipped and regenerated.
(5) After performing the first regeneration step of passing the regenerant in the order of SA layer → WA layer of (ii), the second regeneration step of passing the regenerant through the SA layer → WA layer is performed.
(6) After performing the first regeneration step of passing the regenerant in the order of SA layer → WA layer of (ii), the second regeneration step by immersion regeneration holding the regenerant for a predetermined time is performed. This regeneration step (ii) is usually employed when the multi-layered anion exchange column is of a single column type.
　第２再生工程でＳＡ層の再生を行う場合、再生剤としては、前述の通り、３５℃以上５５℃以下に加温したものを用いることが好ましい。これは、加温した再生剤であれば、ＮａＯＨが速やかに樹脂内に拡散して、シリカを効果的に溶離させることができることによる。 When the SA layer is regenerated in the second regeneration step, it is preferable to use a regenerator that has been heated to 35 ° C. or more and 55 ° C. or less as described above. This is because if the regenerator is heated, NaOH can quickly diffuse into the resin and silica can be effectively eluted.
　第１再生工程で用いる再生剤は、ＷＡ層のみに通液する場合も、ＳＡ層からＷＡ層に通液する場合も、常温であっても加温されていても良く、通常は常温（５℃以上３５℃未満、好ましくは２０℃以上３０℃以下）で良い。 The regenerant used in the first regeneration step may be warmed or warmed, whether it is passed through the WA layer alone or from the SA layer to the WA layer. Or higher and lower than 35 ° C, preferably 20 ° C or higher and 30 ° C or lower).
　第２再生工程でＳＡ層の浸漬再生を行う場合、浸漬温度（浸漬工程において塔内に保持される再生剤の温度）は、浸漬時間によっても異なるが、通常５℃以上５５℃以下、好ましくは常温（５℃以上３５℃未満、好ましくは２０℃以上３０℃以下）である。浸漬工程の時間は通常２０分以上、好ましくは３０～１２０分程度である。上記の温度と時間の範囲で、浸漬温度が高い場合には、浸漬時間を短く、浸漬温度が低い場合は浸漬時間を長くすることが好ましい。 When immersion regeneration of the SA layer is performed in the second regeneration step, the immersion temperature (the temperature of the regenerant retained in the tower in the immersion step) varies depending on the immersion time, but is usually 5 ° C. or more and 55 ° C. or less, preferably It is normal temperature (5 degreeC or more and less than 35 degreeC, Preferably it is 20 degreeC or more and 30 degrees C or less). The time of the dipping process is usually 20 minutes or more, preferably about 30 to 120 minutes. When the immersion temperature is high within the above temperature and time range, the immersion time is preferably shortened, and when the immersion temperature is low, the immersion time is preferably increased.
　浸漬再生の場合、浸漬時間を３０分以上とすることで、常温（５℃以上３５℃未満、好ましくは２０℃以上３０℃以下）の再生剤を用いることができる。浸漬再生の場合は、再生剤の温度に頼らず樹脂内にＮａＯＨを拡散させることができるため、常温（５℃以上３５℃未満、好ましくは２０℃以上３０℃以下）の再生剤を用いることができる。シリカはＳＡの樹脂内部で重合して吸着しているが、浸漬再生であれば、シリカの重合物を分解して溶離させる反応時間を確保することができる効果もある。 In the case of immersion regeneration, a regenerant at room temperature (5 ° C. or more and less than 35 ° C., preferably 20 ° C. or more and 30 ° C. or less) can be used by setting the immersion time to 30 minutes or more. In the case of immersion regeneration, since NaOH can be diffused in the resin without depending on the temperature of the regenerant, a regenerant at room temperature (5 ° C. or more and less than 35 ° C., preferably 20 ° C. or more and 30 ° C. or less) should be used. it can. Silica is polymerized and adsorbed inside the SA resin, but immersion regeneration also has an effect of ensuring a reaction time for decomposing and eluting the polymer of silica.
　以下に実施例を挙げて本発明をより具体的に説明する。 Hereinafter, the present invention will be described more specifically with reference to examples.
　以下の実験例、実施例及び比較例において、強塩基性陰イオン交換樹脂、弱塩基性陰イオン交換樹脂としては次のものを用いた。
　強塩基性アニオン交換樹脂（ＳＡ）：三菱ケミカル株式会社製「ダイヤイオンＳＡ１０ＡＬＯＨ」
　弱塩基性アニオン交換樹脂（ＷＡ）：三菱ケミカル株式会社製「ダイヤイオンＷＡ３０Ｃ」 In the following experimental examples, examples and comparative examples, the followings were used as the strong basic anion exchange resin and the weak basic anion exchange resin.
Strongly basic anion exchange resin (SA): “Diaion SA10ALOH” manufactured by Mitsubishi Chemical Corporation
Weakly basic anion exchange resin (WA): “Diaion WA30C” manufactured by Mitsubishi Chemical Corporation
　「シリカの溶離率」は次のように定義して、これを指標とすることで再生効率を評価した。シリカの溶離率が１００％未満であることは、シリカのゲル化が起きていることを示す。シリカの溶離率の上限は理論的には１００％であるが、繰り返し採水を行った樹脂の場合、前回再生時のシリカ負荷の残留で１００％を超える場合もある。 “Silica elution rate” was defined as follows, and this was used as an index to evaluate regeneration efficiency. A silica elution rate of less than 100% indicates that silica gelation is occurring. The upper limit of the elution rate of silica is theoretically 100%, but in the case of a resin from which water has been repeatedly collected, there may be a case where the silica load remaining at the previous regeneration exceeds 100%.
　シリカの溶離率（％）＝（カラムからの再生廃液中のシリカ総量／供給水のシリカ負荷総量）×１００
　再生廃液中のシリカ総量＝再生廃液中の平均シリカ濃度×再生廃液量
　供給水中のシリカ総量＝供給水中のシリカ濃度×供給水流量×供給時間 Elution rate of silica (%) = (total amount of silica in the regenerated waste liquid from the column / total amount of silica loading of feed water) × 100
Total amount of silica in reclaimed waste liquid = average silica concentration in reclaimed waste liquid x amount of reclaimed waste liquid Total amount of silica in feed water = silica concentration in feed water x supply water flow rate x supply time
　シリカの分析はＪＩＳに準拠して行い、下記の通りとした。
　イオン状シリカ：ＪＩＳ４４．１．２　モリブデン青法
　全シリカ：ＪＩＳ４４．３
　ゲル状シリカ：（ＪＩＳ４４．３による全シリカ分析値）－（ＪＩＳ４４．１．２によるイオン状シリカ分析値） The analysis of silica was performed according to JIS and was as follows.
Ionic silica: JIS 44.1.2 Molybdenum blue method All silica: JIS 44.3
Gel silica: (total silica analysis value according to JIS 44.3)-(ionic silica analysis value according to JIS 44.1.2)
　カラム（φ４０ｍｍのアクリルカラム）への通液、通水は以下の共通の条件と、目的に応じた樹脂量、供給水温度、イオン濃度で行った。 The liquid flow through the column (φ40 mm acrylic column) and water flow were performed under the following common conditions, the amount of resin according to the purpose, the feed water temperature, and the ion concentration.
　供給水の通水：ＬＶ＝４０ｍ／ｈｒで通水
　再生剤の通液：供給水の通水と逆向きに、ＬＶ＝１０ｍ／ｈｒで通水 Feed water flow: LV = 40 m / hr, regenerant flow: Regenerant flow: Reverse direction of feed water flow, LV = 10 m / hr
　再生剤としてはＮａＯＨ水溶液を用い、供給水中の負荷イオン総量に対し、モル比で１１０％となるように量を決めて通液した。 A NaOH aqueous solution was used as a regenerant, and the amount was determined so that the molar ratio was 110% with respect to the total amount of loaded ions in the feed water.
［実験例１］
　２本のカラムの一方に樹脂層高５００ｍｍとなるように、ＳＡを充填し、他方に同じく樹脂層高５００ｍｍとなるように、ＷＡを充填した。このカラムを直列につなぎ、ＷＡカラム→ＳＡカラムの順で、塩化物イオン濃度８０ｍｇ／Ｌ、シリカ濃度４３ｍｇ／Ｌの供給水を、樹脂１Ｌ当たり１５ｇ－ＳｉＯ２／Ｌ－Ｒ（ＳＡ）となるように通水した。 [Experimental Example 1]
One of the two columns was filled with SA so that the resin layer height was 500 mm, and the other was filled with WA so that the resin layer height was 500 mm. This column is connected in series, and in the order of WA column → SA column, feed water with a chloride ion concentration of 80 mg / L and a silica concentration of 43 mg / L becomes 15 g-SiO 2 / LR (SA) per liter of resin. The water passed through.
　再生剤としては４５℃、２重量％のＮａＯＨ水溶液（ｐＨ１３以上）を用い、ＳＡ層→ＷＡ層の順で通液した。 As a regenerant, 45 ° C., 2% by weight NaOH aqueous solution (pH 13 or more) was used, and the solution was passed in the order of SA layer → WA layer.
　ＷＡ充填カラムから排出される塔流出液（再生廃液）のＣｌイオン濃度、イオン状シリカ濃度、コロイダルシリカ濃度及びｐＨの経時変化を調べ、結果をＦｉｇ．１に示した。 Investigate changes over time in Cl ion concentration, ionic silica concentration, colloidal silica concentration and pH of the tower effluent (recycled waste liquid) discharged from the WA packed column, and the results are shown in FIG. It was shown in 1.
　Ｆｉｇ．１より明らかなように、Ｃｌイオンが排出されている（再生廃液に含まれている）間は、ｐＨが低く、シリカは排出されていない（Ｆｉｇ．１の矢印で示される期間）。その後、イオン状シリカが排出される。 Fig. As is clear from FIG. 1, while Cl ions are being discharged (contained in the regenerated waste liquid), the pH is low and silica is not discharged (period indicated by the arrow in FIG. 1). Thereafter, ionic silica is discharged.
　Ｆｉｇ．１より、ｐＨ９、好ましくはｐＨ１０を超える条件であれば、イオン状でシリカが排出されるので、陰イオン交換塔の塔流出液がｐＨ９、好ましくはｐＨ１０を超える条件で再生することにより、ＷＡ層に流入してもシリカのゲル化は起こらないことが分かる。 Fig. From 1, the silica is discharged in an ionic state under a condition that exceeds pH 9, preferably pH 10, so that the effluent of the anion exchange tower is regenerated under a condition that exceeds pH 9, preferably pH 10, so that the WA layer It can be seen that the gelation of silica does not occur even if it flows into the.
［実施例１］
　２本のカラムの一方に樹脂層高５００ｍｍとなるように、ＳＡを充填し、他方に同じく樹脂層高５００ｍｍとなるように、ＷＡを充填した。このカラムを直列につなぎ、ＷＡカラム→ＳＡカラムの順で、塩化物イオン濃度８０ｍｇ／Ｌ、シリカ濃度４３ｍｇ／Ｌの供給水を、樹脂１Ｌ当たり１５ｇ－ＳｉＯ２／Ｌ－Ｒ（ＳＡ）となるように通水した。 [Example 1]
One of the two columns was filled with SA so that the resin layer height was 500 mm, and the other was filled with WA so that the resin layer height was 500 mm. This column is connected in series, and in the order of WA column → SA column, feed water with a chloride ion concentration of 80 mg / L and a silica concentration of 43 mg / L becomes 15 g-SiO 2 / LR (SA) per liter of resin. The water passed through.
　再生剤としては常温（２５℃）、ＮａＯＨ濃度１重量％のＮａＯＨ水溶液を用い、まず、ＷＡカラムにのみ再生剤を通液して塔流出液のｐＨが９になるまで先行再生を行った。塔流出液は系外へ排出した。その後、再生剤を加温（４５℃）して、ＳＡカラム→ＷＡカラムの順に、塔流出液がｐＨ１４となるまで連続通液して再生を行った後、純水のみによる押出しを行った。 As the regenerant, a normal temperature (25 ° C.), NaOH aqueous solution having a NaOH concentration of 1% by weight was used. First, the regenerant was passed through only the WA column, and pre-regeneration was performed until the pH of the tower effluent reached 9. The tower effluent was discharged out of the system. Thereafter, the regenerant was heated (45 ° C.), and the regeneration was conducted by continuously passing the column effluent until the pH reached 14 in the order of the SA column → WA column, followed by extrusion with pure water alone.
　上記の供給水の通水と再生を５回繰り返した後、６回目のシリカの溶離率を計算したところ、１１０％であった。 After the above-mentioned feed water flow and regeneration were repeated five times, the sixth elution rate of silica was calculated and found to be 110%.
［比較例１］
　実施例１において、ＷＡカラムの先行再生を行わずにＳＡカラム→ＷＡカラムの順に連続通液して再生を行った後、純水のみによる押出しを行った。上記の供給水の通水と再生を５回繰り返した後、６回目のシリカの溶離率を計算したところ、９７％であった。 [Comparative Example 1]
In Example 1, regeneration was performed by continuously passing in the order of the SA column → WA column without performing prior regeneration of the WA column, and then extrusion was performed only with pure water. After repeating the above-mentioned feed water flow and regeneration 5 times, the elution rate of the sixth silica was calculated and found to be 97%.
　実施例１と比較例１の結果から、ＷＡ層の先行再生を行うことにより、シリカのゲル化を防止してシリカを効率的に溶離させて再生することができることが分かる。 From the results of Example 1 and Comparative Example 1, it can be seen that by performing the prior regeneration of the WA layer, it is possible to prevent silica gelation and efficiently elute the silica for regeneration.
［実施例２］
　２本のカラムの一方に樹脂層高５００ｍｍとなるように、ＳＡを充填し、他方に同じく樹脂層高５００ｍｍとなるように、ＷＡを充填した。このカラムを直列につなぎ、ＷＡカラム→ＳＡカラムの順で、塩化物イオン濃度８０ｍｇ／Ｌ、シリカ濃度４３ｍｇ／Ｌの供給水を、樹脂１Ｌ当たり１５ｇ－ＳｉＯ２／Ｌ－Ｒ（ＳＡ）となるように通水した。 [Example 2]
One of the two columns was filled with SA so that the resin layer height was 500 mm, and the other was filled with WA so that the resin layer height was 500 mm. This column is connected in series, and in the order of WA column → SA column, feed water with a chloride ion concentration of 80 mg / L and a silica concentration of 43 mg / L becomes 15 g-SiO 2 / LR (SA) per liter of resin. The water passed through.
　再生剤として、ＮａＯＨ濃度１重量％のＮａＯＨ水溶液を用い、ＳＡカラム及びＷＡカラムのそれぞれに、それぞれの樹脂に負荷したイオン量に対し１１０％となるように、再生剤を、塔流出液のｐＨがそれぞれ１４となるまで個別に通液し、塔流出液を系外へ排出した。その後、同様に純水のみによる押出しを行った。なお、再生剤はＷＡカラムには常温（２５℃）、ＳＡカラムには加温（４５℃）で通液した。 A NaOH aqueous solution having a NaOH concentration of 1% by weight was used as the regenerant, and the regenerant was added to each of the SA column and WA column so that the amount of ions loaded on each resin was 110%. Were individually passed until each became 14, and the tower effluent was discharged out of the system. Thereafter, extrusion with pure water alone was similarly performed. The regenerant was passed through the WA column at room temperature (25 ° C.) and through the SA column at warm (45 ° C.).
　上記の供給水の通水と再生を５回繰り返した後、６回目のシリカの溶離率を計算したところ、１０５％であった。 After the above water supply and regeneration were repeated 5 times, the sixth elution rate of silica was calculated to be 105%.
　実施例２より、ＳＡ層とＷＡ層とを別々に個別再生することにより、シリカのゲル化を防止してシリカを効率的に溶離させて再生できることが分かる。 From Example 2, it can be seen that by separately regenerating the SA layer and the WA layer, the silica can be prevented from gelation and efficiently regenerated by eluting the silica.
［実施例３］
　２本のカラムに樹脂層高５００ｍｍとなるように、ＳＡを充填した。この２つのカラムに対し、シリカ濃度４３ｍｇ／Ｌの供給水を樹脂１Ｌ当たり１５ｇ－ＳｉＯ２／Ｌ－Ｒとなるように通水した。 [Example 3]
Two columns were packed with SA so that the resin layer height was 500 mm. Through these two columns, feed water having a silica concentration of 43 mg / L was passed so as to be 15 g-SiO 2 / LR per liter of resin.
　一方のカラムの再生は、温度２５℃、ＮａＯＨ濃度１重量％のＮａＯＨ水溶液（ｐＨ１４以上）を通液することにより行い、塔流出液のｐＨが１３であることを確認した後、３０分封入した。３０分の浸漬工程後に所定量の残りのＮａＯＨ水溶液を通液した後、純水のみによる押出しを行った。この供給水の通水と再生を５回繰り返した後、６回目のシリカの溶離率を計算したところ、１０３％となった。 One column was regenerated by passing a NaOH aqueous solution (pH 14 or higher) having a temperature of 25 ° C. and a NaOH concentration of 1% by weight. After confirming that the pH of the tower effluent was 13, the solution was sealed for 30 minutes. . After passing a predetermined amount of the remaining NaOH aqueous solution after the immersion process for 30 minutes, extrusion with pure water alone was performed. After the feed water was passed and regenerated five times, the sixth elution rate of silica was calculated and found to be 103%.
　他方のカラムには、温度２５℃、ＮａＯＨ濃度１重量％のＮａＯＨ水溶液の全量を通液し、その後純水のみによる押出しを行って再生した。再生時の塔流出液のｐＨは１３となっていた。その後シリカの溶離率を計算したところ、８５％であった。 The other column was passed through the entire amount of NaOH aqueous solution having a temperature of 25 ° C. and a NaOH concentration of 1% by weight, and then regenerated by extruding only with pure water. The pH of the tower effluent during regeneration was 13. Thereafter, the elution rate of silica was calculated to be 85%.
　この結果から、浸漬工程を行うことにより、常温のＮａＯＨ水溶液であってもＳＡからシリカを効率的に溶離させることができることが分かる。 From this result, it can be seen that the silica can be efficiently eluted from SA even by a NaOH aqueous solution at room temperature by performing the dipping process.
　本発明を特定の態様を用いて詳細に説明したが、本発明の意図と範囲を離れることなく様々な変更が可能であることは当業者に明らかである。
　本出願は、２０１６年１１月１０日付で出願された日本特許出願２０１６－２１９８７５に基づいており、その全体が引用により援用される。 Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention.
This application is based on Japanese Patent Application No. 2016-212875 filed on Nov. 10, 2016, which is incorporated by reference in its entirety.

Claims (8)

  1. 　弱塩基性陰イオン交換樹脂層と強塩基性陰イオン交換樹脂層を備え、被処理水が弱塩基性陰イオン交換樹脂層から強塩基性陰イオン交換樹脂層の順に通水された複層式陰イオン交換塔に再生剤を通液して該弱塩基性陰イオン交換樹脂及び強塩基性陰イオン交換樹脂を再生する方法において、
    　(i)再生剤を、該複層式陰イオン交換塔の弱塩基性陰イオン交換樹脂層と強塩基陰イオン交換樹脂層との間から導入し、弱塩基性陰イオン交換樹脂層を通過させて該塔から流出させる工程、もしくは(ii)再生剤を、該複層式陰イオン交換塔の強塩基性陰イオン交換樹脂層側から導入して強塩基性陰イオン交換樹脂層から弱塩基性陰イオン交換樹脂層の順に通過させて該塔から流出させる工程を、塔流出液のｐＨがアルカリ性になるまで継続する第１再生工程と、
    　該第１再生工程後に該強塩基性陰イオン交換樹脂層を再生する第２再生工程とを行うことを特徴とする複層式陰イオン交換塔の再生方法。     A multi-layer system that includes a weakly basic anion exchange resin layer and a strongly basic anion exchange resin layer, and water to be treated is passed in the order of weakly basic anion exchange resin layer to strong basic anion exchange resin layer. In a method for regenerating the weakly basic anion exchange resin and the strongly basic anion exchange resin by passing a regenerant through an anion exchange tower,
    (i) A regenerant is introduced from between the weakly basic anion exchange resin layer and the strong base anion exchange resin layer of the multilayer anion exchange column, and is allowed to pass through the weakly basic anion exchange resin layer. Or (ii) introducing a regenerant from the strongly basic anion exchange resin layer side of the multi-layered anion exchange tower and weakly basic from the strongly basic anion exchange resin layer. A first regeneration step for continuing the step of passing through the anion exchange resin layer in order and flowing out of the column until the pH of the column effluent becomes alkaline;
    A method for regenerating a multi-layer anion exchange column, comprising: performing a second regeneration step of regenerating the strongly basic anion exchange resin layer after the first regeneration step.
  2. 　請求項１において、前記第１再生工程を、前塔流出液のｐＨが９以上となるまで行うことを特徴とする複層式陰イオン交換塔の再生方法。 2. The method for regenerating a multi-layered anion exchange column according to claim 1, wherein the first regeneration step is performed until the pH of the effluent of the front column becomes 9 or more.
  3. 　請求項１又は２において、前記第２再生工程において、前記強塩基性陰イオン交換樹脂層に加温した再生剤を通液することを特徴とする複層式陰イオン交換塔の再生方法。 3. The method for regenerating a multi-layered anion exchange column according to claim 1 or 2, wherein in the second regeneration step, a warming regenerant is passed through the strongly basic anion exchange resin layer.
  4. 　請求項１又は２において、前記第２再生工程において、前記強塩基性陰イオン交換樹脂層を常温の再生剤に所定時間浸漬させることを特徴とする複層式陰イオン交換塔の再生方法。 The method for regenerating a multi-layered anion exchange tower according to claim 1 or 2, wherein, in the second regeneration step, the strongly basic anion exchange resin layer is immersed in a regenerant at room temperature for a predetermined time.
  5. 　請求項１又は２において、前記第１再生工程において、前記(i)の工程を行い、その後、前記第２再生工程において、再生剤を、前記複層式陰イオン交換塔の強塩基性陰イオン交換樹脂層側から導入して強塩基性陰イオン交換樹脂層から弱塩基性陰イオン交換樹脂層の順に通過させて該塔から流出させることにより、前記強塩基性陰イオン交換樹脂層を再生することを特徴とする複層式陰イオン交換塔の再生方法。 In Claim 1 or 2, the said (i) process is performed in the said 1st reproduction | regeneration process, Then, in the said 2nd reproduction | regeneration process, a regenerant is made into the strong basic anion of the said multilayer anion exchange tower. The strong base anion exchange resin layer is regenerated by introducing from the exchange resin layer side, passing through the strong base anion exchange resin layer through the weak base anion exchange resin layer in order, and flowing out from the tower. A method for regenerating a multi-layered anion exchange column.
  6. 　弱塩基性陰イオン交換樹脂層と強塩基性陰イオン交換樹脂層を備え、被処理水が弱塩基性陰イオン交換樹脂層から強塩基性陰イオン交換樹脂層の順に通水された複層式陰イオン交換塔に再生剤を通液して該弱塩基性陰イオン交換樹脂及び強塩基性陰イオン交換樹脂を再生する方法において、
    　(i)再生剤を、該複層式陰イオン交換塔の弱塩基性陰イオン交換樹脂層と強塩基陰イオン交換樹脂層との間から導入し、弱塩基性陰イオン交換樹脂層を通過させて該塔から流出させる工程を、塔流出液のｐＨがアルカリ性になるまで継続する第１再生工程と、
    　該強塩基性陰イオン交換樹脂層を再生する第２再生工程とを行う複層式陰イオン交換塔の再生方法であって、
    　該１再生工程と該第２再生工程とを同時に行い、該第２再生工程において、該強塩基性陰イオン交換樹脂層の再生に用いた再生剤を該弱塩基性陰イオン交換樹脂層を通過させることなく、該複層式陰イオン交換塔外へ排出することを特徴とする複層式陰イオン交換塔の再生方法。     A multi-layer system that includes a weakly basic anion exchange resin layer and a strongly basic anion exchange resin layer, and water to be treated is passed in the order of weakly basic anion exchange resin layer to strong basic anion exchange resin layer. In a method for regenerating the weakly basic anion exchange resin and the strongly basic anion exchange resin by passing a regenerant through an anion exchange tower,
    (i) A regenerant is introduced from between the weakly basic anion exchange resin layer and the strong base anion exchange resin layer of the multilayer anion exchange column, and is allowed to pass through the weakly basic anion exchange resin layer. A first regeneration step in which the step of letting out the column from the tower continues until the pH of the tower effluent becomes alkaline;
    A method for regenerating a multi-layered anion exchange tower that performs a second regeneration step of regenerating the strongly basic anion exchange resin layer,
    The first regeneration step and the second regeneration step are performed simultaneously, and in the second regeneration step, the regenerant used to regenerate the strongly basic anion exchange resin layer passes through the weakly basic anion exchange resin layer. A method for regenerating a multi-layer anion exchange column, wherein the multi-layer anion exchange column is discharged outside the multi-layer anion exchange column.
  7. 　請求項１ないし６のいずれか１項において、前記再生剤を通液する複層式陰イオン交換塔中の前記強塩基性陰イオン交換樹脂はシリカを吸着、保持しており、前記弱塩基性陰イオン交換樹脂は強酸を吸着、保持していることを特徴とする複層式陰イオン交換塔の再生方法。 7. The strong basic anion exchange resin in the multilayer anion exchange column through which the regenerant is passed adsorbs and holds silica, and the weak basic A method for regenerating a multi-layer anion exchange column, wherein the anion exchange resin adsorbs and retains a strong acid.
  8. 　請求項１ないし７のいずれか１項において、前記第１の再生工程に先立つ、被処理水通水時の温度を５～２０℃の範囲に維持することを特徴とする複層式陰イオン交換塔の再生方法。 The multilayer anion exchange according to any one of claims 1 to 7, wherein the temperature of the water to be treated is maintained in a range of 5 to 20 ° C prior to the first regeneration step. How to regenerate the tower.
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5673547A (en) * 1979-11-16 1981-06-18 Asahi Glass Co Ltd Regeneration of anion exchange membrane
JPH06238271A (en) * 1992-10-07 1994-08-30 Christ Ag Conditioning method for ion exchange resin
JPH08224580A (en) * 1995-02-21 1996-09-03 Japan Organo Co Ltd Acid removing apparatus, pure water producing apparatus provided therewith, and weakly basic anion-exchange resin for acid removal
JPH10137752A (en) * 1996-11-14 1998-05-26 Mitsubishi Chem Corp Ion exchange method
JP2000202440A (en) * 1999-01-12 2000-07-25 Japan Organo Co Ltd System for producing highly deionized water
JP2002126541A (en) * 2000-10-23 2002-05-08 Nippon Denko Kk Processing method of boron elute containing alkali
JP2016002540A (en) * 2014-06-19 2016-01-12 栗田工業株式会社 Method and apparatus for regenerating double layer type anion exchange resin column

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5823156B2 (en) * 1978-08-08 1983-05-13 栗田工業株式会社 Pure water production method
CN1069605C (en) * 1998-08-20 2001-08-15 南亚塑胶工业股份有限公司 Method and device for removing formic acid and acetic acid from water of glycol production

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5673547A (en) * 1979-11-16 1981-06-18 Asahi Glass Co Ltd Regeneration of anion exchange membrane
JPH06238271A (en) * 1992-10-07 1994-08-30 Christ Ag Conditioning method for ion exchange resin
JPH08224580A (en) * 1995-02-21 1996-09-03 Japan Organo Co Ltd Acid removing apparatus, pure water producing apparatus provided therewith, and weakly basic anion-exchange resin for acid removal
JPH10137752A (en) * 1996-11-14 1998-05-26 Mitsubishi Chem Corp Ion exchange method
JP2000202440A (en) * 1999-01-12 2000-07-25 Japan Organo Co Ltd System for producing highly deionized water
JP2002126541A (en) * 2000-10-23 2002-05-08 Nippon Denko Kk Processing method of boron elute containing alkali
JP2016002540A (en) * 2014-06-19 2016-01-12 栗田工業株式会社 Method and apparatus for regenerating double layer type anion exchange resin column

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