JP2014188440A - Method for regenerating ion exchange column and ion exchange apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for regenerating an ion exchange column capable, even if a body of treatment target water is used as water for regeneration, of obtaining a desired water quality.SOLUTION: The provided method includes a backwash step of feeding backwash water into a column body 11 and then discharging, out of the column body 11, suspended substances together with the backwash water (Figure 2 (b)), a chemical injection step of injecting, into the column body 11 following the backwash step, an acid for regenerating a high-acidity cation exchange resin monolayer 12 (Figure 2 (c)), and an expulsion step of feeding, following the chemical injection step, expelling water into the column body 11 and then discharging, out of the column body 11, a concentrate acid remaining within the column body 11 together with the expelling water (Figure 2 (d)). Treatment target water is used as the backwash water and/or expelling water. An acid is fed, together with the expelling water, into the column body 11 at the expulsion step (Figure 2 (d)).

Description

  The present invention relates to a method for regenerating an ion exchange column in which a column body is filled with an ion exchange resin.

  As a technique regarding the regeneration method of the ion exchange tower (the regeneration method of the ion exchange resin in the ion exchange tower), for example, there are those described in Patent Documents 1 and 2. As described in Patent Documents 1 and 2, pure water and demineralized water are conventionally used as regeneration water in the backwashing step and the extrusion step in the regeneration step of the ion exchange tower. These pure water and demineralized water are treated water treated in an ion exchange tower (treated with an ion exchange apparatus including an ion exchange tower).

Japanese Patent No. 3162614 Japanese Patent No. 3907013

  When treated water (pure water or demineralized water) treated with an ion exchange tower (ion exchange device) is used as regeneration water, there are the following problems.

  The ion exchange device is usually provided with a treated water tank for storing treated water. When treated water (pure water or demineralized water) treated in an ion exchange tower is used as reclaimed water, the capacity of the treated water tank needs to allow for the amount of reclaimed water. Similarly, an apparatus constituting an ion exchange device other than the treated water tank, such as an ion exchange tower, needs to have a treatment capacity in consideration of the amount of water for regeneration. For this reason, conventionally, the ion exchange device is very large compared to the amount of water to be treated.

  Here, if the treated water treated in the ion exchange tower can be used as the regeneration water without using the treated water (pure water or demineralized water) treated in the ion exchange tower as the regeneration water, the ion exchange tower is included. It becomes possible to dramatically reduce the size of the ion exchange device.

  However, when the water to be treated is simply used as the water for regeneration, the ion exchange resin is contaminated with the water to be treated in the extrusion process in the regeneration process. Thereafter, when water flow is started (when treatment of water to be treated is started), contaminants leak from the contaminated ion exchange resin, and a desired water quality cannot be obtained.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for regenerating an ion exchange tower that can obtain a desired water quality even when treated water is used as water for regeneration. It is.

  The present invention is a method for regenerating a countercurrent regeneration type ion exchange column in which a column body is filled with an ion exchange resin. In this regeneration method, backwashing water is supplied to the tower main body, and the backwashing process for discharging suspended substances to the outside of the tower main body together with the backwashing water, and a chemical for regenerating the ion exchange resin after the backwashing process A chemical injection process for injecting into the tower main body, and an extrusion process for supplying extrusion water to the tower main body after the chemical injection process and discharging the chemical remaining in the tower main body together with the extrusion water to the outside of the tower main body. . Water to be treated is used as the backwash water and / or the extrusion water, and the chemical is supplied to the tower body together with the extrusion water in the extrusion step.

  Further, the present invention is a method for regenerating a countercurrent regeneration type ion exchange tower in which an ion exchange resin is packed in a tower body, wherein backwashing water is supplied to the tower body, and the suspended substance together with the backwashing water. And a chemical injection step for injecting a chemical that regenerates the ion exchange resin into the tower body after the backwash process, and using treated water as the backwash water In the chemical injection step, the method is also a regeneration method of the ion exchange tower in which the diluted chemical is injected into the tower body.

  In another category, the present invention can be regarded as an invention of an ion exchange device. That is, the present invention provides a counter-current regeneration type ion exchange tower in which the tower body is filled with an ion exchange resin, a pump for supplying treated water to the tower body as water for regeneration of the ion exchange resin, and an ion exchange resin. It is also an ion exchange device comprising a chemical injection means for injecting a chemical to be regenerated into the tower body and a diluted chemical injection means for injecting a chemical thinner than the chemical into the tower body.

  According to the present invention, the desired water quality can be obtained even if the water to be treated is used as water for regeneration. By using treated water as reclaimed water, a pump and piping for sending reclaimed water, which had been separately provided in the past, are no longer required. As a result, the ion exchange apparatus including the ion exchange tower can be greatly downsized. It becomes possible. Further, the amount of ion exchange resin to be used can be reduced as compared with the conventional one, and the cost can be reduced.

It is a block diagram which shows the ion exchange apparatus which concerns on one Embodiment of this invention. It is a figure which shows each process in the regeneration method of the ion exchange tower which concerns on one Embodiment of this invention. It is a block diagram which shows the modification of the ion exchange apparatus shown in FIG.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The ion exchange tower (ion exchange device) described below is of a countercurrent regeneration type for performing downward circulation water / upward flow regeneration, but the present invention is directed to upward circulation water / downward flow regeneration. The present invention can also be applied to a counter-current regenerative ion exchange tower (ion exchange apparatus) that performs the above.

(Configuration of ion exchanger)
As shown in FIG. 1, the ion exchange apparatus 100 is an apparatus comprising a cation tower 1, a decarboxylation tower 2, an anion tower 3, and the like.

The cation tower 1, the decarboxylation tower 2, and the anion tower 3 are connected to each other by pipes, and these pipes are provided with a plurality of valves (application of water to be treated, supply of chemicals, switching of flow paths, etc.) 17 to 30) are attached to the necessary portions. The drive of the valves (17 to 30) may be electric, manual, or pneumatic.
The configuration of the ion exchange apparatus 100 shown in FIG. 1 is merely an example, and the actual apparatus is usually provided with valves (valves) and devices other than those shown in FIG. Further, the actual apparatus may not adopt the piping configuration and valve arrangement shown in FIG.

(Cation tower)
The cation tower 1 is for adsorbing and removing cations (cations such as Ca ²⁺ , Mg ²⁺ , Na ^+, etc.) contained in the water to be treated, and the tower main body 11 is filled with a strongly acidic cation exchange resin. This is a counter-current regeneration type ion exchange tower (formed with a strongly acidic cation exchange resin monolayer 12).

  The cation exchange resin layer formed in the tower body 11 may be a multilayer of a strong acid cation exchange resin layer and a weak acid cation exchange resin layer. In the case of a multilayer of a strong acid cation exchange resin layer and a weak acid cation exchange resin layer, as in the case of the anion tower 3 described later, at the boundary between the strong acid cation exchange resin layer and the weak acid cation exchange resin layer, It is preferable that a partition wall that allows water to pass but not cation exchange resin is provided.

  To-be-treated water is supplied to the cation tower 1 from the raw water pump 4. At the time of passing water (when treating the water to be treated), the valves 17, 18 and 20 are opened to make downward circulating water (valves 19, 21, and 29 are closed). At the time of regeneration (when regenerating the cation exchange resin in the tower body 11), the valves 17, 21 and 19 are opened to perform upward flow regeneration (valves 20 and 18 are closed). The valve 29 is opened only at the time of the water washing step described later.

  The cation column 1 is supplied with an acid (for example, hydrochloric acid (HCl)) from a chemical injection pump 7. When the cation tower 1 is regenerated, the acid is supplied from the chemical injection pump 7 below the strongly acidic cation exchange resin single layer 12 in the tower body 11. The chemical injection pump 7 is chemical injection means for injecting chemicals for regenerating the ion exchange resin into the tower body 11.

  Note that it is not always necessary to use a pump as the medicine injection means. For example, an acid (chemical) may be supplied from a chemical tank (not shown) to the cation tower 1 (ion exchange tower) with an ejector using the treated water from the raw water pump 4 as driving water. In this case, the raw water pump 4 also serves as a medicine injection means.

The discharge amount of the medicine pump 7 is controlled by the controller 9. The controller 9 is a dilute chemical injection means for injecting a dilute acid (chemical) into the tower body 11.
Note that a plurality of chemical injection pumps 7 may be provided, and a dilute acid (chemical) may be injected into the tower body 11 by performing, for example, switching control of the number of operating chemical injection pumps 7. In this case, the controller that performs the switching control is the lean chemical injection means.
In addition, when the raw water pump 4 is used as the medicine injection means (when an ejector method is used), for example, the amount of medicine injection is adjusted by adjusting the opening degree of the valve 22 or switching the opening / closing operation of a plurality of valves 22 installed. In this case, the valve 22 is a lean drug injection means.

(Decarbonation tower)
The decarbonation tower 2 is for removing CO ₂ contained in the water to be treated, and includes an intermediate water tank 31 in the lower part. Air is supplied from the blower 6 to the decarbonation tower 2.

The treated water leaving the cation tower 1 and introduced into the decarbonation tower 2 is in countercurrent contact with the air from the blower 6. The gasified CO ₂ is released from the upper part of the decarboxylation tower 2.

(Anion tower)
The anion tower 3 is for adsorbing and removing anions (anions such as SO ₄ ²⁻ , NO ₃ ⁻ , Cl ^−, etc.) contained in the water to be treated (decarbonated water). Counter-current regeneration, which is filled with a strong base anion exchange resin and a weak base anion exchange resin (a multilayer of the strong base anion exchange resin layer 15 and the weak base anion exchange resin layer 14 is formed). It is an ion exchange tower of the formula.

  At the boundary between the strong base anion exchange resin layer 15 and the weak base anion exchange resin layer 14, a partition wall 16 that allows water to pass but does not pass the anion exchange resin is provided.

  The anion exchange resin layer formed in the tower body 13 may be a strongly basic anion exchange resin single layer.

  To-be-treated water (decarbonated water) is supplied to the anion tower 3 from the decarbonated water pump 5. At the time of water flow (when decarbonated water is treated), the valves 23, 24, and 26 are opened to provide downward circulating water (valves 25, 27, and 30 are closed). During regeneration (when the anion exchange resin in the tower body 13 is regenerated), the valves 17, 27, and 25 are opened, and the water to be treated is supplied from the raw water pump 4 so that the upward flow is regenerated. (Valves 26 and 24 are closed). The valve 30 is opened only during the water washing step described later.

  The configuration shown in FIG. 3 may be used as the configuration around the anion tower 3. In this case, the cation tower treated water is stored in advance in the intermediate water tank 31 of the decarbonation tower 2, and the valves 23, 27, and 25 are opened during regeneration (when the anion exchange resin in the tower body 13 is regenerated). Then, the water to be treated is supplied from the decarbonated water pump 5 to regenerate upward flow (valves 26 and 24 are closed). The water exiting from the intermediate water tank 31 is treated water when viewed from the anion tower 3.

Returning to FIG. The anion tower 3 is supplied with alkali (for example, caustic soda (NaOH)) from the chemical injection pump 8. When the anion tower 3 is regenerated, alkali is supplied from the chemical injection pump 8 below the strong base anion exchange resin layer 15 in the tower body 13. The chemical injection pump 8 is chemical injection means for injecting chemicals for regenerating the ion exchange resin into the tower body 13.
As a modified example of the medicine injection means, there is an ejector method using the raw water pump 4 as in the case of the cation tower 1 described above.

The discharge amount of the medicine pump 8 is controlled by the controller 10. The controller 10 is a dilute chemical injection means for injecting a dilute alkali (chemical) into the tower body 13.
As a modification of the dilute chemical injection means, as in the case of the cation tower 1 described above, the opening number adjustment of the valve 28 in the case of adopting the switching controller for the number of operating units when a plurality of chemical injection pumps 8 are provided and the ejector system. Or the opening / closing operation | movement switching of the valve | bulb 28 installed in two or more is mentioned.

(Regeneration method of ion exchange tower)
Next, a regeneration method (regeneration operation) of the ion exchange tower will be described with reference to FIG. The difference in the regeneration method between the cation tower 1 and the anion tower 3 is that the ion exchange resin to be regenerated and the chemical used for regeneration are cation exchange resin or anion exchange resin, acid or alkali, respectively. Since there is no need to redundantly explain the regeneration methods of both (cation tower 1 and anion tower 3), the regeneration method (regeneration operation) of cation tower 1 will be described as a representative.

Fig.2 (a) shows the state at the time of water flow (when processing a to-be-processed water) before a reproduction | regeneration driving | operation. During the water flow, the water to be treated is pressurized by the raw water pump 4 and supplied to the cation tower 1 from the upper part of the tower body 11. The treated water supplied to the cation tower 1 passes through the strong acid cation exchange resin single layer 12 and exits from the lower part of the tower body 11. When passing through the strongly acidic cation exchange resin single layer 12, cations such as Ca ²⁺ , Mg ²⁺ , and Na ⁺ contained in the water to be treated are adsorbed by the strong acid cation exchange resin, so that these water can be removed from the water to be treated. Cations are removed.

  In addition, in Fig.2 (a), the water which comes out from the lower part of the tower main body 11 is described with the treated water. This means treated water of the cation tower 1, and the deanion treatment is performed in the anion tower 3 in the subsequent stage. That is, the water exiting from the lower part of the tower body 11 is treated water when viewed from the anion tower 3.

  When the adsorption capacity (ion exchange capacity) of the strong acid cation exchange resin single layer 12 is lost (when it is reduced), the strong acid cation exchange resin single layer 12 (cation tower 1) in the order shown in FIGS. ).

(Backwashing process (FIG. 2B))
The raw water pump 4 is driven, the water to be treated is supplied as backwash water into the tower body 11 from the lower part of the tower body 11, and the suspended substances in the tower body 11 are discharged to the outside of the tower body 11 together with the backwash water. To do.

  At this time, the linear flow velocity (LV) of the upward flow in the column main body 11 is set to a high flow velocity (25 LV to 30 LV) at which the strong acid cation exchange resin single layer 12 is pressed against the upper portion in the column main body 11. As a result, the strong acid cation exchange resin single layer 12 is pressed and fixed to the upper part in the tower body 11.

(Chemical injection process (Figure 2 (c)))
An acid (hydrochloric acid, sulfuric acid, etc.) is injected into the tower body 11 from the lower part of the tower body 11 by the chemical pump 7 while the strong acid cation exchange resin single layer 12 is pressed against the upper part of the tower body 11. The acid is supplied from the chemical injection pump 7 so that the concentration of the acid (in the tower body 11) at the time when it is supplied into the tower body 11 becomes a predetermined concentration in the range of 1 wt% to 5 wt%, for example. Injected. That is, the acid concentration of 1 wt% and 5 wt% described above is a concentration in a mixed state of the acid solution discharged from the chemical injection pump 7 and the water to be treated supplied from the raw water pump 4.

(Extrusion process (FIG. 2 (d)))
When the regeneration of the strong acid cation exchange resin monolayer 12 is completed, an acid that is dilute than the acid used in the chemical injection process is supplied into the tower body 11 from the lower part of the tower body 11 together with the water to be treated as extrusion water. Then, the thick chemical (acid) remaining in the tower body 11 is discharged from the upper part of the tower body 11 to the outside. In addition, supplying an acid that is more dilute than the acid used in the chemical injection step into the tower main body 11 together with the water to be treated as the extrusion water means that when the acid is supplied into the tower main body 11 (in the tower main body 11 ) The acid is supplied into the column main body 11 so that the concentration of the acid becomes thinner than that in the chemical injection process. Although it is not necessary to specify, the type of acid (chemical) used in the chemical injection process and the type of acid (chemical) used in the extrusion process are usually the same, but different types of acids (chemicals) are used in both processes. ) May be used.

It should be noted that the acid (chemical) in the tower main body 11 at the time when it is supplied into the tower main body 11 is equivalent (same as in the chemical injection process) to the acid (chemical) in the tower main body 11. (Chemicals) may be supplied. For example, when the chemical injection process is carried out at an acid concentration of about 1 wt% (for example, sulfuric acid is used as the acid), the column from the chemical injection pump 7 is adjusted so that the same acid concentration (sulfuric acid concentration) of about 1 wt% is obtained in the extrusion process. In some cases, acid (sulfuric acid) is supplied into the main body 11.
The same applies to the anion tower 3. The chemical injection process is performed by setting the alkali concentration to a predetermined concentration in the range of 1 wt% to 5 wt%, for example. Here, for example, when the chemical injection process is performed at an alkali concentration of about 1 wt% (for example, NaOH is used as an alkali), the chemical injection pump is set so that the same alkali concentration (NaOH concentration) is also about 1 wt% in the extrusion process. In some cases, alkali (NaOH) is supplied from 8 into the column main body 13.

  In addition, supplying the acid thinner than the acid used in the chemical injection process into the tower body 11 together with the water to be treated as the extrusion water is to reduce the amount of injected acid compared to the case of the chemical injection process, In the present embodiment, it means that the discharge amount of the medicinal pump 7 is lowered by the controller 9 as compared with the time of the medicating process.

If only the water to be treated is used as the water for regenerating the ion exchange resin (backwash water and / or extruded water), it is close to the treated water inlet of the strong acid cation exchange resin single layer 12 in the extrusion step. The resin (the lower end portion of the strong acid cation exchange resin single layer 12) is contaminated with the water to be treated. The resin close to the treated water inlet of the strong acid cation exchange resin single layer 12 (the lower end portion of the strong acid cation exchange resin single layer 12) is a water passage (when treating the treated water). The resin closest to the treated water outlet. Further, being contaminated with the water to be treated means that, for example, Ca ²⁺ , Mg ²⁺ , Na ^{+ and the} like contained in the water to be treated are adsorbed by the cation exchange resin.
After that, when water flow is started in a state where the cation exchange resin closest to the treated water outlet is contaminated with the treated water (when treatment of the treated water is started), contaminants leak from the contaminated cation exchange resin. The desired water quality cannot be obtained.

  Therefore, in this embodiment, in the extrusion process in which extrusion water is supplied to the tower body 11 and the thick chemical (acid) remaining in the tower body 11 is discharged to the outside of the tower body 11 together with the extrusion water, it is used in the chemical injection process. A chemical (e.g., acid) that is more dilute than the chemical (acid) that is present is supplied to the tower body 11 together with the extrusion water.

A dilute chemical is a concentration that creates a state in which H ⁺ is preferentially exchanged and adsorbed in the strength (ion selection system) in which the cation exchange resin exchanges and adsorbs various cations when the chemical is an acid. It is the chemical | medical agent of a density | concentration lower than the density | concentration in the conventional chemical injection process. The same applies to the case where the chemical is alkali (in the case of anion tower 3). In this case, in the above sentence, “cation” should be read as “anion” and “H ⁺ ” should be read as “OH ⁻ ”.

The concentration of the chemical (in the tower main body 11) at the time when it is supplied to the tower main body 11 of the cation tower 1 (in other words, the concentration of the chemical in a mixed state with the extrusion water (treated water)) is diluted. An acid is an acid having a concentration of acid (for example, hydrochloric acid or sulfuric acid) of, for example, 0.1 wt% or more and less than 1 wt%.
Further, the concentration of the chemical (in the tower main body 13) at the time when it is supplied to the tower main body 13 of the anion tower 3 (in other words, the concentration of the chemical in a mixed state with the extrusion water (treated water)) The dilute alkali is an alkali having an alkali (for example, NaOH) concentration of 0.1 wt% or more and less than 1 wt%, for example.

(Quiet process (Fig. 2 (e)))
The supply of the water to be treated and the acid to the tower body 11 is stopped, and the strongly acidic cation exchange resin single layer 12 pressed against the upper part in the tower body 11 is allowed to settle downward in the tower body 11. The strong acid cation exchange resin constituting the strong acid cation exchange resin single layer 12 is loosened while settling.

(Washing process (FIG. 2 (f)))
Water to be treated is passed from the upper part of the tower body 11 and discharged from the lower part of the tower body 11, and acid equivalent to the chemical injection process supplied in the extrusion process or thinner than in the chemical injection process is excluded. If circulation is carried out with a large amount of acid or alkali remaining in the tower, for example, acid Cl and alkali Na may become loads on the anion tower 3 and cation tower 1, respectively, and the performance may be reduced. This can be prevented by doing so.

(Circulation process (Fig. 2 (g)))
Until the treated water quality reaches the target water quality, the treated water in which the treated water (treated water that has passed through the cation tower 1, the decarboxylation tower 2, and the anion tower 3) is returned to the raw water pipe is circulated (note that In FIG. 1, the circulation means such as circulation piping is not shown).

  The above is the entire process of the regeneration method (regeneration operation) of the cation tower 1.

(Action / Effect)
In the present invention, water to be treated is used as water for ion-exchange resin regeneration (backwash water and / or extrusion water), and in the extrusion process, it is used in a chemical having the same concentration as in the chemical injection process or in the chemical injection process. A thinner chemical than the chemical is supplied to the tower body along with the extrusion water.

According to this structure, it can prevent that an ion exchange resin is contaminated with to-be-processed water in an extrusion process. As a result, it is possible to suppress leakage of contaminants from the ion exchange resin during subsequent water flow (when the water to be treated is treated). In the extrusion process, when the chemical is an acid, a state in which H ⁺ is preferentially exchange-adsorbed is created, and when the chemical is an alkali, a state in which OH ⁻ is preferentially exchange-adsorbed is created. .
As a result, the desired water quality can be obtained even if the water to be treated is used as water for regeneration. By using the water to be treated as the water for regeneration, it is possible to dramatically reduce the size of the ion exchange device including the ion exchange tower.

(Modification)
A concentration that creates a state in which H ⁺ or OH ⁻ is preferentially exchanged and adsorbed, and a concentration of a chemical (acid or alkali) that is lower than the concentration in the conventional chemical injection process, that is, a dilute chemical (acid or alkali). If the chemical injection process is carried out using this method (if the ion exchange resin is regenerated), no thick chemical will remain in the column itself. That is, if a chemical injection process is performed using a dilute chemical, the subsequent extrusion process can be omitted.

(Comparative experiment)
A comparative experiment was conducted between the regeneration method of the present invention using treated water as the regeneration water and the conventional regeneration method using pure water as the regeneration water.

  As a common condition, 410 mL of a strongly acidic cation exchange resin was charged into a cation tower having a diameter of 23 mm × H (height) of 1200 mm.

<Experimental results using the conventional regeneration method>
Pure water and HCl were mixed to prepare a 5 wt% HCl solution, and initial regeneration was performed with 300 g-HCl / LR (corresponding to a chemical injection process). Then, the extrusion process was performed with pure water (initial regeneration process completed).
The city water of T-C70 mg-CaCO ₃ / L was passed through this cation tower as the water to be treated, once it was broken through, once mixed with pure water and HCL again, and 1 L of resin in 5 wt% HCl solution. The chemical injection at 50 g-HCL / LR per hit and the extrusion with pure water were performed (regeneration process completed). Through this cation tower, city water of T-C70 mg-CaCO ₃ / L was passed as treated water to obtain treated water quality: 0.04 mS / m, BTC: 53 g-CaCO ₃ / LR.

<Results of experiment by the regeneration method of the present invention>
T-C 70 mg-CaCO ₃ / L city water as the water to be treated was mixed with HCl to prepare a 5 wt% HCl solution, which was regenerated with 50 g-HCl / LR HCl (drug injection process) Equivalent to Thereafter, an extrusion process was performed at 12.5 g-HCL / L-R per liter of resin with a solution of 0.5 wt% HCl solution in city water of T-C 70 mg-CaCO ₃ / L (regeneration process completed) ).
Through this cation tower, city water of T-C70 mg-CaCO ₃ / L was passed as treated water to obtain treated water quality: 0.09 mS / m, BTC: 66 g-CaCO ₃ / LR.

  As a result of the comparative experiment described above, it was verified that the treated water quality similar to the conventional one can be obtained by the regeneration method of the present invention.

1: Cation tower (ion exchange tower)
2: Decarboxylation tower 3: Anion tower (ion exchange tower)
4: Raw water pump 5: Decarbonated water pump 6: Blower 7, 8: Chemical injection pump (chemical injection means)
9, 10: Controller (dilute drug injection means)
11, 13: Tower main body 12: Strongly acidic cation exchange resin single layer 14: Weakly basic anion exchange resin layer 15: Strongly basic anion exchange resin layer 16: Partition 100: Ion exchange apparatus

Claims (6)

A countercurrent regeneration type ion exchange tower regeneration method in which an ion exchange resin is packed in a tower body,
A backwashing step of supplying backwashing water to the tower body and discharging suspended substances together with the backwashing water to the outside of the tower body;
After the backwashing step, a chemical injection step for injecting a chemical for regenerating the ion exchange resin into the tower body,
After the chemical injection step, supply extrusion water to the tower body, and an extrusion process for discharging the chemical remaining in the tower body together with the extrusion water to the outside of the tower body;
With
Using treated water as the backwash water and / or the extrusion water,
A method for regenerating an ion exchange tower, wherein, in the extrusion step, the chemical is supplied to the tower body together with the extruded water. In the regeneration method of the ion exchange tower of Claim 1,
In the extrusion process, a method for regenerating an ion exchange tower, wherein a chemical thinner than the chemical used in the chemical injection step is supplied to the tower body together with the extrusion water. A countercurrent regeneration type ion exchange tower regeneration method in which an ion exchange resin is packed in a tower body,
A backwashing step of supplying backwashing water to the tower body and discharging suspended substances together with the backwashing water to the outside of the tower body;
After the backwashing step, a chemical injection step for injecting a chemical for regenerating the ion exchange resin into the tower body,
With
Using treated water as the backwash water,
A method for regenerating an ion exchange column, wherein in the chemical injection step, the diluted chemical is injected into the tower body. A counter-current regeneration type ion exchange tower in which the tower body is filled with an ion exchange resin;
A pump for supplying water to be treated to the tower body as water for ion exchange resin regeneration;
A chemical injection means for injecting chemicals for regenerating the ion exchange resin into the tower body;
A dilute chemical injection means for injecting a chemical thinner than the chemical into the tower body;
An ion exchange apparatus comprising: The ion exchange apparatus according to claim 4,
When the chemical is an acid, the ion exchange resin layer packed in the tower body is a strong acid cation exchange resin single layer or a multiple layer of a strong acid cation exchange resin layer and a weak acid cation exchange resin layer,
When the chemical is alkali, the ion exchange resin layer packed in the tower body is a strong basic anion exchange resin single layer, or a multilayer of a strong basic anion exchange resin layer and a weak basic anion exchange resin layer. There is an ion exchange device. In the ion exchange device according to claim 4 or 5,
When the chemical is an acid, the ion exchange resin layer packed in the tower body is a multilayer of a strong acid cation exchange resin layer and a weak acid cation exchange resin layer, and the strong acid cation exchange resin layer and the At the boundary with the weakly acidic cation exchange resin layer, a partition that allows water to pass but not cation exchange resin is installed,
When the chemical is alkali, the ion exchange resin layer packed in the tower body is a multilayer of a strong basic anion exchange resin layer and a weak basic anion exchange resin layer, and the strong basic anion exchange resin An ion exchange apparatus in which a partition wall through which water passes but does not pass through an anion exchange resin is installed at the boundary between the layer and the weakly basic anion exchange resin layer.

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