JP2014057945A - Processing method of polyvalent metal ion inclusion water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method in which when raw water including a polyvalent metal ion performed by water conduction to a filling layer that comprises filling a titanate based adsorbent granulation body to be processed, a problem of breaking and fastening of a titanate based adsorbent granulation body does not exist even when continuing long time treatment, and moreover efficient treatment can be performed by maintaining adsorption ability of a polyvalent metal ion high.SOLUTION: When a filling layer that comprises filling a titanate based adsorbent granulation body that is obtained by when a titanate is added with a binder including a clay mineral and water, and granulation is performed, then burning is performed, water conduction is performed on raw water including a polyvalent metal ion to perform adsorption treatment of a polyvalent metal ion in raw water, raw water in which a pH is adjusted to 7-12 is performed by water conduction to a filling layer of a titanate based adsorbent granulation body.

Description

  In the present invention, a titanate-containing adsorbent granule obtained by firing after adding a binder containing clay mineral and water and granulating the titanate is filled with a polyvalent metal. The present invention relates to a method for treating polyvalent metal ion-containing water by passing raw water containing ions and adsorbing and removing polyvalent metal ions in the raw water.

  Since titanic acid-based adsorbents have high Sr adsorption capacity, their use as Sr adsorbents for group separation in nuclear fuel reprocessing is being studied.

Regarding the Sr adsorption treatment using titanic acid-based Sr adsorbent, several reports have been made heretofore, and Non-Patent Document 1 describes the distribution coefficient Kd and adsorption rate when titanic acid is granulated with a binder. It is described that it becomes smaller.
Further, in Patent Document 1, as a method for producing a sodium titanate ion exchanger that adsorbs radioactive strontium, hydrous titanium oxide is slurried with a liquid composed of alcohol and sodium hydroxide, heated, filtered, dried and then crushed. A method for classifying and manufacturing granular sodium titanate having a sodium / titanium molar ratio of 0.6 or less has been proposed (Patent Document 1).

Non-Patent Document 1 describes a glass column test using titanic acid granulated with a binder, but does not describe the optimum conditions.
Patent Document 1 describes that a good amount of adsorption can be obtained at pH 10 or higher in an adsorbent in which titanium oxide is titanated in a slurry state, dried and then crushed into granules.

Japanese Patent No. 4428541

"Development of group separation method: Adsorption behavior of Sr on titanic acid granulated with binder" JAERI-Research 98-026, May 1998

  Granular sodium titanate produced by the method described in Patent Document 1 is an aggregate of primary particles, so the strength is weak, and it is pulverized by vibration or impact applied during transportation, etc. When put in water, the primary particles fall off due to the collapse of the aggregates. For this reason, there existed a subject that the finely divided particle | grains and primary particle obstruct | occluded the strainer of an adsorption tower, or passed the adsorption tower strainer, and the fine powder with radiation leaked from an adsorption tower.

Therefore, the present inventors mixed titanate and clay mineral with an appropriate amount of water and granulated, and when the granulated product was dried and calcined, it was found that a strong adsorbent granule was obtained. I found it. However, when this adsorbent granule was subjected to adsorption equilibrium test and column test under various conditions, the adsorbent granule was disintegrated or fixed by passing water for a long time. There were still issues in practical use, such as inability to achieve performance.
When the adsorbent granule is collapsed, as described above, the adsorbent tower is blocked by the dropped adsorbent particles, and there is a problem of leakage from the adsorber tower. Further, when the adsorbent granule is fixed, water passing is poor, and it is difficult to discharge the adsorbent granule from the adsorption tower after the treatment. In addition, a decrease in the adsorption capacity of the adsorbent granule leads to a decrease in adsorption efficiency.

  The present invention provides a titanic acid-based adsorbent produced even if the treatment is continued for a long time when the raw water containing polyvalent metal ions is passed through the packed bed filled with the titanic acid-based adsorbent granules. It is an object of the present invention to provide a method in which there is no problem of particle disintegration and fixation, and an efficient treatment can be performed while maintaining a high adsorption capacity for polyvalent metal ions.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have obtained a titanic acid-based adsorbent granule-packed layer in terms of the adsorptive capacity of the titanate-based adsorbent granule and the resistance as a filler. The present inventors have found that the pH of raw water passing through the water is an important factor, and completed the present invention.
That is, the gist of the present invention is as follows.

[1] A titanate-containing adsorbent granule obtained by firing after adding a binder containing clay mineral and water to a titanate and granulating it is filled with a polyvalent metal ion. In the method for treating polyvalent metal ion-containing water, wherein the polyvalent metal ion containing water is adsorbed and removed by adsorbing and removing polyvalent metal ions in the raw water, the pH of the raw water is 7 to 12 Treatment method of ion-containing water.

[2] The method for treating polyvalent metal ion-containing water according to [1], wherein the raw water has a pH of 7 to 10.

[3] The raw water contains Mg as a polyvalent metal. After adjusting the pH of the raw water to 11.5 or more and separating Mg as magnesium hydroxide, the pH is adjusted to 7 to 10 to The method for treating water containing polyvalent metal ions according to [2], wherein water is passed through the packed bed.

[4] The raw water contains Sr as a polyvalent metal, the pH of the raw water is 11 or more, and the carbonic acid concentration is adjusted to 1.0 to 2.0 equivalents of the Sr concentration in the raw water to carbonate Sr. After separating as strontium, the pH is adjusted to 7 to 10 and water is passed through the packed bed, [2] or [3], the method for treating polyvalent metal ion-containing water according to [2].

  According to the present invention, after adding a binder containing clay mineral to titanate and water and granulating, the packed bed filled with titanic acid-based adsorbent granules obtained by firing is used to form a polyvalent metal. When processing raw water containing ions, the raw water pH is adjusted to the optimum pH range, so that the adsorption ability of polyvalent metal ions can be maintained high over a long period of time. Stable and efficient treatment can be performed without the problem of body collapse and sticking.

It is a graph which shows the pH dependence of the adsorption capacity (partition coefficient Kd) of a titanic acid type adsorbent granule. It is a graph which shows the time-dependent change of the treated water Sr density | concentration of the column water flow test in Example 1,2. It is a systematic diagram showing a mode in which raw water is passed through a packed bed (adsorption tower) of titanate-based adsorbent granule after roughening of polyvalent metal ions in the present invention.

  Hereinafter, embodiments of the present invention will be described in detail. However, the embodiments described below are for facilitating the understanding of the present invention and are not intended to limit the present invention. In the range which does not exceed the gist, each element disclosed in the following embodiments can be implemented with various modifications.

[Raw water pH]
In the present invention, after adding a binder containing clay mineral and water to titanate and granulating, the packed bed filled with titanate-based adsorbent granule obtained by firing, pH 7-12, Preferably, raw water containing polyvalent metal ions having a pH of 7 to 10 is passed.
A method for producing the titanate-based adsorbent granule used in the present invention will be described later.

  In the present invention, the reason why the pH of the raw water passing through the packed bed of the titanate-based adsorbent granule is 7 to 12, preferably 7 to 10 is as follows.

As will be described later, in the firing step of the titanate-based adsorbent granule used in the present invention, firing cannot be performed at a temperature exceeding 900 ° C. so as not to exceed the melting point of titanate. However, in order to completely sinter the clay mineral used as the binder, it is necessary to fire at a high temperature of 1200 to 1300 ° C. It is thought that it exists in the state which is not sintered. In such a state, when acidic raw water is passed, the clay mineral dissolves little by little and the adsorbent granule collapses. Therefore, the pH of the raw water needs to be 7 or higher.
In addition, as described above, Si eluted from the clay mineral that has not been completely sintered is colloidalized, the packed bed is solidified to inhibit water flow, and the adsorbent granule is discharged from the packed bed. Although it becomes difficult, if the pH of the raw water is 12 or less, the degree of fixation can be reduced. By setting the pH to 10 or less, that is, pH 7 to 10, no sticking occurs and long-time passage is possible. Water becomes possible.

  In addition, although there is no restriction | limiting in particular as water quality other than pH of the polyvalent metal ion containing raw water applied to this invention, For example, Sr is 0.01-10 mg / L, Mg is 0.01-100 mg / L, Ca is used. The waste water containing 0.01-100 mg / L is mentioned. When the pH of these wastewaters deviates from the above-mentioned preferred pH, the pH may be adjusted by adding an acid such as HCl or an alkali such as NaOH prior to passing water.

[Water flow conditions]
In the present invention, there are no particular restrictions on the conditions for passing the raw water through the packed bed of titanic acid-based adsorbent granules, and it can be carried out according to a conventional method. In normal cases, it is preferable from the viewpoint of processing efficiency and adsorption efficiency that the water flow SV is 5 to 50 / hr and the LV is 1 to 60 m / hr.

[Rough removal of polyvalent metal ions]
In the present invention, as shown in FIG. 3, before passing raw water through the adsorption tower 3 provided with a packed bed filled with titanate-based adsorbent granules, polyvalent metal ions are aggregated and solid-liquid separated. By roughing, the lifetime of the titanate-based adsorbent granule can be extended.
That is, when Mg is contained in the raw water, a pH adjuster is added in the reaction tank 1 as necessary prior to passing water through the adsorption tower 3 provided with a packed bed of titanate-based adsorbent granules. By adjusting the pH to 11.5 or more, preferably 12 to 13.5, Mg is precipitated as magnesium hydroxide, and this is solid-liquid separated by solid-liquid separation means 2 such as sedimentation separation or membrane separation. Thus, by separating the magnesium hydroxide, Mg supplied to the adsorption tower 3 can be greatly reduced, and the life of the titanate-based adsorbent granule can be extended.
Similarly, when the raw water contains Ca or Sr, a pH adjuster is used as necessary in the reaction tank 1 prior to water flow to the adsorption tower 3 provided with a packed layer of titanate-based adsorbent granule. Is added to adjust the pH to 11 or more, preferably pH 11.5 to 13.5, and carbonate is added as necessary to adjust the carbonic acid concentration to 1.0 to 2. By adjusting to 0 equivalent, Ca and Sr are precipitated as calcium carbonate and strontium carbonate, and separated by solid-liquid separation by solid-liquid separation means 2 such as sedimentation separation and membrane separation. Ca and Sr supplied to the tower 3 can be greatly reduced, and the life of the adsorbent can be extended.

  In either case, usually, a part of the sludge separated by the solid-liquid separation means 2 is discharged out of the system, and the remainder is returned to the reaction tank 1 as return concentrated water.

  When the pH of the raw water after the above treatment is out of pH 7-12, an acid such as HCl is added to adjust to pH 7-12, preferably pH 7-10, and titanate-based adsorbent granule. Pass water through the packed bed.

[Titanate-based adsorbent granules]
Below, the manufacturing method of the titanic acid type adsorbent granule used by this invention is demonstrated.
However, the method for producing a titanate-based adsorbent granule described below is merely an example of the method for producing a titanate-based adsorbent granule used in the present invention, and the present invention is limited to the following method. It is not something.

  The titanate-based adsorbent granule used in the present invention is mixed with a binder containing titanate, water and clay mineral as described below, granulated after the obtained kneaded material is dissipated, Next, it is preferable that the granulated product is classified, dried, classified, and fired to produce an adsorbent granule having high strength.

<Titanate>
The titanate used as the adsorption component of the titanate-based adsorbent granule is M ₂ Ti _n O _{2n + 1} (n = 1 to 9) or M ₄ Ti _n O _{2n + 2} (n = 1, 3, 5, 9). expressed. M is preferably sodium, potassium, or ammonium, and more preferably sodium or potassium in terms of adsorption ability.
A titanate may be used individually by 1 type, and may use together 2 or more types from which the cation M and a composition formula differ.

<Kneading water>
Water for mixing with titanate to obtain a kneaded product is preferably added so that the water content in the obtained kneaded product is 20 to 60% by mass, particularly 30 to 50% by mass. The amount of the kneaded water is preferably maintained as the water content of the kneaded product even in the kneaded product after the heat dissipation step. The water content of the kneaded product can be measured with a moisture meter of the heat drying / mass measurement method.
Even if the water content of the kneaded product is less than the above lower limit or exceeds the above upper limit, a good granulated product may not be obtained.

<Binder>
A clay mineral is used as the binder.

  As the clay mineral, for example, one or more of bentonite, attapulgite, sepiolite, allophane, halloysite, imogolite, kaolinite and the like can be used. The clay mineral is a natural product, is cheaper than silicate compounds which are other binders described later, and is advantageous for practical use. Among the clay minerals, it is preferable to use a fibrous clay mineral such as attapulgite or sepiolite from the viewpoint of the mechanical strength of the obtained granular material.

  In addition, you may use things other than a clay mineral together as a binder, In this case, as another binder, sodium silicate, calcium silicate, magnesium silicate, sodium metasilicate, calcium metasilicate, magnesium metasilicate One or more of silicate compounds such as sodium aluminate metasilicate, calcium aluminate metasilicate, and magnesium aluminate metasilicate can be used.

  However, in order to effectively obtain the effect of the present invention applied to a titanic acid-based adsorbent granule using clay mineral as a binder, when other binder is used, the other binder is 10% of all binder components. It is preferable to set it as mass% or less.

It is also preferable to add a plasticizer that gives plasticity necessary for granulation together with the binder.
Examples of the plasticizer include starch, corn starch, molasses, lactose, cellulose, cellulose derivatives, gelatin, dextrin, gum arabic, alginic acid, polyacrylic acid, glycerin, polyethylene glycol, polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), Examples include methanol and ethanol. These may be used individually by 1 type, and 2 or more types may be mixed and used for them.

  After mixing the titanate, binder, and plasticizer at a predetermined mixing ratio, after heat dissipation, granulated and molded, dried, and then fired, granulated titanate-based adsorbent with even higher mechanical strength You can get a body.

The usage-amount of a binder is not specifically limited, It is preferable that it is 0.1-0.5 mass part with respect to 1 mass part of titanate. The greater the amount of binder used, the stronger the resulting granulated product. However, if the amount of binder is too large, the amount of pure titanate decreases, and the Sr adsorption amount of the resulting Sr adsorbent decreases, which is not preferable. .
Moreover, the usage-amount of a plasticizer is not specifically limited, It is preferable that it is 0.01-0.1 mass part with respect to 1 mass part of titanate. If the usage-amount of a plasticizer is in the said range, a titanate can be granulated effectively.

<Mixing process>
The mixing step is a step of sufficiently generating heat by applying a strong shear force and mixing a binder containing titanate, water and clay mineral, preferably further a plasticizer, in a closed system where moisture is not released. It is preferable.

  As described above, mixers for mixing with a strong shear force include high-speed bottom stirring, drum rotating, single-shaft ribbon, double-shaft paddle, rotating saddle, biaxial planetary stirring, conical planets Screw type, continuous rotating disk type, continuous high speed paddle type, fixed pan type roller type, container bottom swing type, etc. can be used. Can be given.

In the mixing step, it is preferable that the kneaded material of the binder containing titanate, water, and clay mineral, preferably the kneaded material in which the plasticizer is mixed, is mixed until the temperature reaches 60 ° C. or higher. If the temperature rises to 60 ° C. or higher during mixing, the temperature rises again in the subsequent granulation step or sizing step, and the strength of the titanate-based adsorbent granule obtained by evaporating the water decreases. The phenomenon can be prevented.
The rising temperature in this mixing step is more preferably 65 ° C. or higher, but it is preferably 100 ° C. or lower in order to prevent an increase in pressure in the closed system.

<Heat dissipation process>
After the mixing step, it is preferable to perform a heat dissipation step for reducing the temperature of the kneaded product.
The heat dissipation step can be performed, for example, by leaving the kneaded material in a container to dissipate heat. At this time, the kneaded material may be left in the mixer, or the kneaded material may be transferred from the mixer to another heat radiating container and left to stand. In any case, it is preferable that the container be sealed so that moisture does not rise from the kneaded material having an increased temperature. However, it is preferable to leave an appropriate air hole or gap so that the internal pressure of the mixer or the heat dissipation container does not increase. In addition, installing a refrigerant pipe in the mixer or radiator container to cool the mixer or radiator container can shorten the heat radiation time, and the heat radiation process can be performed in the flow of mixing, heat radiation, granulation, and sizing. It can prevent becoming rate-limiting.

In the heat dissipation step, it is preferable to dissipate heat until the temperature of the kneaded product reaches 50 ° C. or lower. If the temperature after this heat dissipation is higher than 50 ° C., the strength improvement effect by providing the heat dissipation process may not be sufficiently obtained.
The standing time in the heat radiation process depends on the heat radiation efficiency, but is preferably 30 to 120 minutes in the case of natural heat radiation and 10 to 60 minutes in the case of cooling with a refrigerant or the like.
Moreover, it is preferable to adjust the leaving time of a heat dissipation process so that the moisture content of the granulated material obtained at the following granulation process may be 20-60 mass%, especially 30-50 mass%.
When heat is dissipated in the mixer, it is preferable from the viewpoint of energy saving to stop mixing in the mixer.

  In such a heat dissipation step, it is preferable to lower the temperature of the kneaded product to about 30 to 50 ° C. because the water content of the granulated product obtained in the next granulating step can be easily adjusted to an appropriate range.

<Granulation process>
The kneaded product whose temperature has been reduced in the heat dissipation step is then granulated in the granulation step.

  As the granulation method in the granulation process, specifically, a rolling granulation method using a drum granulator, a dish granulator, etc .; mixed stirring granulation using a flexo mix, a vertical granulator, etc. Extrusion granulation method using screw type extrusion granulator, roll type extrusion granulator, blade type extrusion granulator, self-molding type extrusion granulator, etc .; tablet type granulator, briquette type granulation Compression granulation method using a machine, etc .; fluidized bed structure that granulates by spraying a binder such as water or alcohol while keeping the titanate powder and binder suspended and suspended in the fluid to be blown up (mainly air) Examples of the granulation method include an extrusion granulation method in view of mass productivity.

The size of the Sr adsorbent granule obtained in this way is preferably 150 to 3000 μm, particularly 300 to 2000 μm in terms of particle size. If the size of the granulated product is larger than the above range, the surface area becomes small, so that the Sr adsorption capacity is lowered, and if it is small, there is a risk of leakage from the strainer of the adsorption tower.
Here, the particle size of the granulated product corresponds to the diameter if the granulated product is spherical, and in the case of other shapes, when the granulated product is sandwiched between two parallel plates, The length of the part where the distance between the plates is the largest (the distance between the two plates) is indicated.

<Sizing, drying, classification, firing process>
The granulated product obtained in the granulation step is sized, dried and classified as necessary, and then fired in an air atmosphere, so that the titanate-based adsorbent has excellent handling properties as a water treatment material. It can be set as a granulated body. Here, drying is preferably performed at 70 to 150 ° C. and baking is performed at 500 to 900 ° C.

  In the firing treatment, if the firing temperature is less than 500 ° C., the unsintered portion remains and the particle strength becomes weak, and if it exceeds 900 ° C., the structure of the titanate crystal is affected and the adsorption performance decreases. End up.

  The firing time varies depending on the firing temperature and the size of the granulated product, but is usually about 0.5 to 10 hours.

  Hereinafter, the present invention will be described more specifically with reference to experimental examples, examples, and comparative examples.

[Experimental Examples 1 and 2]
In order to confirm the pH dependence of the adsorptive capacity (partition coefficient Kd) of the adsorbent composed of titanate, an adsorption equilibrium test with varying pH was performed.
After adding 0.05 g of potassium titanate to 5 mL of simulated water (Na 10,000 mg / L, Sr 1 mg / L) and shaking for 24 hours, the distribution coefficient Kd was determined from the Sr concentration in water. In addition, pH was adjusted with HCl or NaOH so that it might become predetermined pH.
The results are shown in FIG.
FIG. 1 shows that the Sr adsorption capacity of titanate is enhanced under conditions where the pH of the raw water is 7-12.

[Examples 1 and 2]
<Production of titanic acid-based adsorbent granules>
3 kg of potassium titanate powder and 2.8 L of water, 0.6 kg of attapulgite and PVA (dissolved in 2.8 L of water so as to form a 5% by mass aqueous solution) as a granulation aid, almost sealed high-speed bottom stirring The mixture was put into a mixer (because it had air holes, so there was no pressure increase) and mixed for 1 minute. The temperature of the kneaded product at the end of mixing was 67 ° C. This kneaded product is left in a high-speed bottom stirring mixer for 1 hour to dissipate heat and the temperature is lowered to 48 ° C., and the kneaded product after temperature reduction is put into a roll type extrusion granulator with a die diameter of 0.6 mm. Then, granulation was performed at a load of 120 rpm and a granulation rate of 140 dry-kg / hr.
The obtained granulated product (particle size 600 μm, moisture content 40% by mass) is sized with a spherical sizer, dried at 110 ° C. with a fluidized bed dryer, classified with a sieve, and heated to 800 ° C. with a muffle furnace. And calcined for 2 hours to produce titanate-based adsorbent granules.

<Column flow test>
The obtained titanic acid-based adsorbent granule is filled into a glass column, and a column water flow test is performed under the following conditions using raw water having the following water quality, and the Sr concentration of the treated water (column effluent) changes over time. The results are shown in FIG.
Raw water quality pH: 7 (Example 1) or 10 (Example 2)
Sr: 50 mg / L
Ca: 10 mg / L
Mg: 1mg / L
NaCl: 10,000 mg / L
-Water flow conditions Column capacity: 13 mL
Filling amount: 19g
SV: 10 / hr
LV: 130 mL / hr

  As is clear from FIG. 2, both Examples 1 and 2 were capable of passing water of 300 BV or more. In this column flow test, there was no increase in the differential pressure during column flow, and the titanate-based adsorbent granules after the test were smoothly taken out.

[Comparative Example 1]
A column water flow test was conducted in the same manner as in Example 1 except that water whose pH was adjusted to 3 with HCl was passed. As a result, the titanate-based adsorbent granule in the column collapsed and the differential pressure was reduced. Increased and it became impossible to continue water flow at 150 BV.

[Comparative Example 2]
A column water flow test was conducted in the same manner as in Example 1 except that water whose pH was adjusted to 12.5 with NaOH was passed. As a result, the differential pressure increased and water flow could not be continued at 250 BV. . When an attempt was made to take out the titanate-based adsorbent granule from the column, it was confirmed that the particles of the adsorbent granule were fixed to each other to form a lump.

  From the above results, it can be seen that a favorable treatment can be performed by adjusting the raw water pH to be passed through the packed bed of the titanic acid-based adsorbent granule in the range of 7 to 12, particularly 7 to 10.

[Experiment 3]
A test was conducted to roughen the polyvalent metal salt in the simulated water of the following water quality by coagulation.
<Simulated seawater quality>
Conductivity: 4420 mS / m
Ca: 417 mg / L
Mg: 1260mg / L
Sr: 4.28 mg / L
pH: 8.2

After adding 1200 mg / L of Na ₂ Co ₃ as carbonate to simulated sea water and adjusting the pH to 12 by adding NaOH and reacting for 10 minutes, an anionic polymer (“Cliff Lock PA823” manufactured by Kurita Kogyo Co., Ltd.) (acrylic) 3 mg / L of acid-based polymer)) was added and coagulated for 5 minutes, and then allowed to stand for 30 minutes for precipitation separation. The supernatant water was filtered through a filter having a pore size of 0.45 μm, the filtrate was analyzed, and the results are shown in Table 1.

[Experimental Example 4]
In Experimental Example 3, treatment was performed in the same manner except that Na ₂ Co ₃ was not added to the simulated seawater, and the results are shown in Table 1.

  From Table 1, it can be seen that Experimental Example 3 in which carbonate and alkali were added at the front stage of the adsorption tower and agglomeration treatment was performed was able to efficiently remove Sr in the simulated seawater together with Ca and Mg. On the other hand, in Experimental Example 4 in which no carbonate was added, since no carbonate was added, Sr was hardly removed. However, by setting the pH to 12, Mg was satisfactorily removed, and Ca was also partially. Removed. From Experimental Examples 3 and 4, it can be seen that the load on the adsorption tower can be significantly reduced by performing the agglomeration treatment at the front stage of the adsorption tower.

1 Reaction tank 2 Solid-liquid separation means 3 Adsorption tower

Claims (4)

  Raw water containing polyvalent metal ions in a packed bed formed by adding titanate-based adsorbent granules obtained by granulating a binder containing clay mineral and water after adding it to titanate A polyvalent metal ion-containing water characterized by having a pH of 7 to 12 in the method of treating water containing polyvalent metal ions by passing water and adsorbing and removing polyvalent metal ions in the raw water Processing method.   The method for treating polyvalent metal ion-containing water according to claim 1, wherein the raw water has a pH of 7 to 10.   The raw water contains Mg as a polyvalent metal, and after adjusting the pH of the raw water to 11.5 or higher and separating Mg as magnesium hydroxide, the pH is adjusted to 7 to 10 in the packed bed. The method for treating polyvalent metal ion-containing water according to claim 2, wherein water is passed.   The raw water contains Sr as a polyvalent metal, and the pH of the raw water is 11 or more, and the carbonic acid concentration is adjusted to 1.0 to 2.0 equivalents of the Sr concentration in the raw water to separate Sr as strontium carbonate. After that, the pH is adjusted to 7 to 10 and water is passed through the packed bed. The method for treating polyvalent metal ion-containing water according to claim 2 or 3.

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