JP2003190948A - Method and apparatus for ion exchange treatment of vanadium-containing water - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for the ion exchange treatment of vanadium-containing water, capable of efficiently removing vanadium and other ions and not deteriorate an ion exchange resin due to the catalystic action of vanadium. <P>SOLUTION: Vanadium-containing water is supplied to a vanadium removing column 1 and passed through zeolite 2 to remove vanadium and other ions. The treated water from the column 1 is passed through a cation exchange resin bed and an anion exchange resin bed 7 both of which are provided to a rear stage to remove residual ions. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an ion exchange method and apparatus for vanadium-containing water for removing vanadium and other impurities from water to be treated containing vanadium, and in particular vanadium-containing water for removing vanadium and other impurities by zeolite. The present invention relates to an ion exchange method and device.

[0002]

2. Description of the Related Art Vanadium is used as a catalyst and is contained not only in the ash of coal, petroleum, etc., but also in certain natural waters. Vanadium-containing water contains various forms of vanadium depending on its origin. Vanadium forms various compounds depending on the valence of -I to + V, and each compound includes one in which vanadium dissociates into cations and one in which vanadium dissociates into anions. When vanadium is contained in an ionic or ionizable state like a soluble salt, vanadium can be removed by ion exchange.

In the above vanadium-containing water in which the vanadium compound contained therein is dissociated into cations, vanadium can be removed by cation exchange. Some groundwater in volcanic ash soil contains vanadium compounds that dissociate into cations, and vanadium-containing water containing such vanadium compounds is removed by cation exchange by adsorbing vanadium dissociated into cations onto an ion exchanger. It is possible to

For example, when vanadium-containing water is treated with a cation exchange resin, vanadium is concentrated in the resin by exchange adsorption. However, the vanadium compound is widely used as a catalyst, and the activity varies depending on the valence of vanadium or the kind of the compound, but many vanadium compounds have catalytic activity. When vanadium having such a catalytic activity is concentrated in the cation exchange resin, the cation exchange resin undergoes oxidative deterioration due to its catalytic action, and as a result, decomposition and production of a relatively high polymer containing the exchange group of the cation exchange resin occurs. The substance (for example, polystyrene sulfonic acid) flows out into the treated water, and the cation exchange ability decreases. In addition, the relatively high-molecular-weight decomposition products such as polystyrene sulfonic acid that flow out deteriorate the quality of treated water, and if there is an anion exchange resin in the subsequent stage, it becomes a load and shortens the regeneration cycle of the anion exchange resin. There is.

[0005]

The object of the present invention is to ion-exchange vanadium-containing water which can efficiently remove vanadium and other ions and which does not cause deterioration of the ion exchanger due to the catalytic action of vanadium. It is to propose a method and an apparatus.

[0006]

The present invention is the following method and apparatus for ion exchange of vanadium-containing water. (1) Ion-exchange method for vanadium-containing water in which vanadium-containing water is brought into contact with zeolite in the previous stage to remove vanadium, and the treated water is brought into contact with a cation-exchange resin and / or anion-exchange resin in the latter stage to remove residual ions . (2) An ion exchange device for vanadium-containing water, comprising a vanadium removal tower filled with zeolite, and an ion exchange tower provided at a subsequent stage of the vanadium removal tower and filled with a cation exchange resin layer and / or an anion exchange resin layer.

The vanadium-containing water to be treated in the present invention is water containing vanadium in a state capable of cation exchange, and examples thereof include water containing vanadium as a cation or in a state capable of dissociating into a cation. It may contain vanadium dissociated into vanadium, a vanadium compound dissociable into anions, a vanadium compound not ionized, a cation other than vanadium, an anion other than vanadium, or other impurities. As the vanadium-containing water to be treated in the present invention, vanadium dissociated into cations or vanadium dissociable into cations is 0.1
Those containing more than μg / L are suitable for treatment. Specific examples of the vanadium-containing water to be treated in the present invention include natural water, river water, especially groundwater of volcanic ash ground, underground water, deep well water, and the like.

Vanadium forms a compound having a valence of -I to + V as described above, of which + II to + V are common. At oxidation numbers II and III, a salt mainly forms as a cation, but at oxidation number IV, it combines with oxygen to form VO.
Often forms ²⁺ salts. When the oxidation number is V, VO ³⁺ or V
It forms a salt of the metavanadate ion VO ₃ ⁻ with the salt of O ₂ ⁺ . V ₂ O _5, which is widely used as a catalyst in the amphoteric slightly soluble in water, when dissolved in an acid to produce a VO ₂ ^+, the alkaline aqueous solution dissociates into the anion generated metavanadate ions.

As described above, vanadium forms compounds having various valences. Natural water, especially groundwater of volcanic ash ground, underground water, and deep well water, often contain vanadium that dissociates into cations. Wastewater discharged from a system using a vanadium catalyst includes one that dissociates into cations and one that dissociates into anions depending on the pH.

In the present invention, vanadium-containing water is brought into contact with zeolite in the preceding stage, and vanadium dissociated into cations is exchange-adsorbed by zeolite to be removed. In this case, the zeolite is used as an ion exchanger.

As the zeolite used in the present invention, known ones having a cation exchange ability can be used, and it may be natural zeolite or synthetic zeolite, and these granular or powdery ones can be used. The granular zeolite used as the ion exchanger in the present invention is H type or Na type.
Can be used in the form. To prepare it in the H form, regenerate the zeolite with hydrochloric acid, sulfuric acid, etc., and to prepare it in the Na form, NaCl
It is performed by playing back with etc. Regeneration to the H form can also be carried out by passing a regenerated effluent that regenerates the cation exchange resin used in the ion exchange column of the deionized water producing apparatus or the like provided in the subsequent stage. Further, although powdered zeolite has a large surface area and a large adsorption rate and adsorption capacity, it is preferable, but it is difficult to recycle, and it is generally discarded after use.

When the vanadium-containing water is brought into contact with the zeolite, vanadium is exchange-adsorbed by the zeolite and vanadium is removed from the vanadium-containing water. When the cation other than vanadium is contained in the vanadium-containing water, the cation is also exchange-adsorbed. For example, when Na type zeolite is used, other cations such as Ca and Mg are also exchange-adsorbed.

The contact between the vanadium-containing water and the zeolite can be carried out by, for example, passing vanadium-containing water through a vanadium removing tower filled with granular or powdery zeolite. The conditions of water flow can be the same as in the ordinary ion exchange treatment. The water flow rate varies depending on the vanadium concentration of the vanadium-containing water, the water treatment target value, etc., but generally 0.05 to 50 L / L-zeolite / h.
r, preferably 0.1 to 5 L / L-zeolite / hr. The completion of water flow can be determined by detecting leakage of ions and the like into the treated water. In this case, when the vanadium-containing water contains other cations such as calcium in addition to vanadium like natural water, the vanadium ends when the vanadium starts to leak. Also, when the vanadium-containing water contains only vanadium, the process ends when the vanadium leaks.

By continuing the flow of water, vanadium is exchange-adsorbed by the zeolite and concentrated. Water can be stopped and regenerated at the time when ions etc. start to leak. However,
Discard the powdered zeolite and replace it with a new one. For regeneration, hydrochloric acid, sulfuric acid, NaCl or the like is passed as a regenerant as described above, and then extrusion, washing with water or the like is performed to complete the regeneration. Further, as the regenerant, it is also possible to use the regenerated drainage of the cation exchange resin of the ion exchange column in the latter stage. By the regeneration, vanadium and other cations adsorbed on the zeolite are eluted and the zeolite is regenerated.
When hydrochloric acid or sulfuric acid is used as a regenerant, H type, NaC
When 1 is used, it is regenerated to Na form. The regenerated zeolite is reused, and exchange adsorption by ion exchange is performed by restarting water flow.

The ion exchange column in the latter stage uses a cation exchange resin and / or an anion exchange resin, and a pure water producing apparatus, an ultrapure water producing apparatus using both of them is preferable. In such a pure water production apparatus and an ultrapure water production apparatus, pretreatment for vanadium removal has not been conventionally performed. Therefore, when vanadium-containing water is passed as water to be treated, the ion exchange resin is activated due to the activity of vanadium. Was deteriorated due to oxidation, and the processing performance was deteriorated. In the present invention, the vanadium removal tower is provided as a pretreatment device in the front stage, so vanadium and other ions are efficiently removed in the front stage, and the ion exchange resin in the post stage is prevented from deteriorating the ion exchange resin by vanadium, and the ion exchange resin is removed. Ion exchange can be performed while maintaining high efficiency. Moreover, since the zeolite does not undergo oxidative deterioration due to vanadium, the decomposition products do not flow out even if vanadium is concentrated in the zeolite, and therefore, as in the case of removing vanadium by using a cation exchange resin instead of the zeolite. The decomposition products do not load the anion exchange resin in the subsequent stage, and the regeneration cycle of the ion exchange resin in the subsequent stage is not shortened.

The vanadium-containing water ion exchange apparatus of the present invention has a vanadium removal column filled with zeolite in the front stage and an ion exchange column containing a cation exchange resin layer and / or an anion exchange resin layer in the rear stage. As the ion exchange tower in the latter stage, an ion exchange tower that is usually used as a pure water production apparatus, an ultrapure water production apparatus or the like is used. As for the configuration and operation of the ion exchange column provided in the subsequent stage, the regeneration method, and the like, known ones can be adopted. New cation exchange resins and anion exchange resins are used. A new acid or alkali can be used as the regenerant.

The vanadium-containing water ion exchange method and apparatus of the present invention can efficiently remove vanadium. The zeolite used in the present invention does not undergo oxidative deterioration even if vanadium is concentrated therein, and the zeolite can be repeatedly used by regeneration. In addition, since decomposition products such as polystyrene sulfonic acid due to oxidative deterioration do not elute, no load is applied to the ion exchange resin in the subsequent stage, and the regeneration cycle of the ion exchange resin in the subsequent stage is not shortened.

The vanadium-containing water ion exchange method and apparatus of the present invention can be applied to wastewater treatment and effluent treatment as long as it is vanadium-containing water. It is preferably applied as a pure water production method or a pure water production apparatus having a configuration provided with an ion exchange tower for pure water production.

[0019]

According to the present invention, vanadium-containing water is brought into contact with zeolite in the preceding stage to remove vanadium and other ions, so that vanadium and other ions can be efficiently removed, Moreover, since the oxidative deterioration due to the catalytic action of vanadium does not occur, the zeolite can be used repeatedly, and the regeneration cycle of the ion exchange resin in the subsequent stage is not shortened.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a flow chart showing an ion exchange apparatus for vanadium-containing water according to an embodiment. In FIG.
Reference numeral 1 is a vanadium removal tower, inside of which zeolite 2 is packed. Reference numeral 3 denotes an ion exchange tower (pure water producing apparatus), which is composed of a cation exchange tower 4 and an anion exchange tower 5, and has an H type cation exchange resin layer 6 and an OH, respectively.
The anion exchange resin layer 7 in the shape is filled.

The water passage L1 to be treated is connected to the vanadium removal tower 1, the transfer passage L2 is connected from the vanadium removal tower 1 to the cation exchange tower 4, the transfer passage L3 is connected from the cation exchange tower 4 to the anion exchange tower 5, The treatment water channel L4 communicates with the anion exchange resin tower 5. Further, the vanadium removal tower 1 is connected to the regenerant passage L6 and the regeneration drainage passage L7, and the cation exchange tower 4 is connected to the regenerant passage L8 and the regeneration drainage passage L9.
The regenerant line L10 and the regenerated drainage line L are connected to the anion exchange tower 5.
11 is in contact. It is also possible to provide a regeneration drainage transfer passage L12 that branches from the regeneration drainage passage L9 and communicates with the regeneration agent passage L6.

In the ion exchange method of vanadium-containing water by the above-mentioned ion exchange apparatus, vanadium-containing water as treated water is supplied from the treated water channel L1 to the vanadium removal tower 1 and passed through the zeolite 2 to remove vanadium and other substances. Exchange and adsorb the ions. Even if vanadium is concentrated in zeolite 2 by ion exchange,
Does not deteriorate due to oxidation. The treated water of the vanadium removal tower 1 enters the cation exchange tower 4 of the ion exchange tower 3 from the transfer path L2,
By passing through the cation exchange resin layer 6, the remaining cations are exchange-adsorbed and removed. The cation exchange-treated water enters the anion exchange tower 5 through the transfer passage L3, passes through the anion exchange resin layer 7, and the anions are exchange-adsorbed, and the treated water (pure water) is taken out through the treatment water passage L4.

In the above treatment, vanadium and other ions are removed in the vanadium removing tower 1, so that vanadium is not adsorbed in the cation exchange resin layer 6 and therefore the cation exchange resin layer 6 is deteriorated by vanadium. Since it is not received and other cations are removed, the cation exchange capacity of the ion exchange column 3 is maintained high. Moreover, even if vanadium is concentrated in the zeolite 2, the zeolite 2 does not undergo oxidative deterioration, so that the zeolite 2 is not decomposed in the vanadium removal tower 1 and the decomposed product is not brought into the ion exchange tower 3 in the subsequent stage. The decomposition product does not flow into the ion exchange column 3 and the performances of the cation exchange resin layer 6 and the anion exchange resin layer 7 are not deteriorated, and the cation exchange resin layer 6 and the anion exchange resin layer 7 in the subsequent stage are regenerated. It does not shorten the cycle.

Although the above-mentioned apparatus is provided with washing water or air for washing (backwashing) and other pipes, pumps, valves, deaeration and decarbonation equipments, they are omitted. Is illustrated. Regeneration of Zeolite 2 is regenerant path L
The regeneration agent (acid or NaCl aqueous solution) is supplied from 6 to the vanadium removal tower 1 to be regenerated, and the regenerated drainage is discharged from the regeneration drainage path L7. When the regeneration waste liquid transfer passage L12 is provided, the regeneration waste liquid discharged from the regeneration waste liquid passage L9 is supplied to the vanadium removal tower 1 from the regenerant passage L6 through the regeneration waste liquid transfer passage L12 to regenerate the zeolite 2. Can also be used for. The cation exchange resin layer 6 is regenerated by supplying a regenerant (acid) from the regenerant line L8 to the cation exchange column 4 to regenerate it into the H shape, and the regenerated drainage is discharged from the regenerated drainage line L9. The anion exchange resin layer 7 is regenerated by supplying a regenerant (alkali) from the regenerant line L10 to the anion exchange column 5 to regenerate it into an OH form, and the regenerated drainage is discharged from the regenerated drainage line L11.
Operations such as backwashing, extrusion, and washing are the same as those in a normal ion exchange apparatus.

According to the above ion exchange apparatus, pure water or ultrapure water can be efficiently produced from natural water, for example.

[0026]

EXAMPLES The present invention will be described below with reference to Examples and Comparative Examples.

Example 1 (Preparation of sample zeolite) X-type zeolite (Na ₂ O.
120 g of Al ₂ O ₃ .2SiO ₂ ) was added to a glass column (28
mmφ × 500 mmH). Then, 1 L of pure water
The column was washed by passing water.

(Preparation of water to be treated) About 13.0 g of vanadium sulfate oxide (VOSO ₄ .nH ₂ O) and about 10.3 g of calcium chloride (CaCl ₂ .2H ₂ O) were added to 20 L of pure water.
Dissolved in water, and each of V ion and Ca ion is 140
It was adjusted to be mg / L.

(Water flow test) About 3 L / L-
Water was passed through a zeolite-filled glass column at a water flow rate of zeolite / hr, and V and Ca ions of the column-treated water were analyzed to confirm the adsorption performance. Also, as playback confirmation, p
Regeneration was performed with a hydrochloric acid solution adjusted to H4 at a chemical injection rate of about 2 L / L-zeolite / hr, and the adsorption performance after regeneration was confirmed. The results are shown in Table 1.

[0030]

[Table 1]

As can be seen from the results shown in Table 1, both vanadium ion and calcium ion are adsorbed on the X-type zeolite (calcium ion is more selective),
Moreover, pH 4 (weakly acidic) with hydrochloric acid is not sufficient, but it is regenerated and can be reused.

Comparative Example 1 Vanadium ion and calcium ion were each 5
The water to be treated prepared so as to be 0 mg / l was passed through the resin column only under strong water cation exchange resin (Monoplus S100, manufactured by Bayer Co., Ltd.) under the water flow condition of SV≈7.6. I did the test. The calcium ion concentration in the treated water is 0.1 to 0.3 mg / l, the vanadium ion concentration is 0.2 to 0.6 mg / l, and the polystyrene sulfonic acid (PSA) having a water passage ratio of 200 or more is 3.5 to 6. 5 mg
/ L, TOC became 1.5 to 3.0 mg / l.

[Brief description of drawings]

FIG. 1 is a flow diagram showing an ion exchange apparatus for vanadium-containing water according to an embodiment.

[Explanation of symbols]

1 Vanadium removal tower 2 Zeolite 3 ion exchange tower 4 Cation exchange tower 5 Anion exchange tower 6 Cation exchange resin layer 7 Anion exchange resin layer

Continued front page    (72) Inventor Mitsukazu Masudo             Kurita, 3-4-3 Nishi-Shinjuku, Shinjuku-ku, Tokyo             Industry Co., Ltd. F-term (reference) 4D025 AA01 AA03 AA04 AA09 AB21                       BA03 BA08 BA11 BA13 BA22                       BB02 BB09

Claims (2)

[Claims] 1. An ion of vanadium-containing water for removing vanadium by bringing vanadium-containing water into contact with zeolite in the former stage to remove vanadium, and then bringing the treated water into contact with a cation-exchange resin and / or anion-exchange resin in the latter stage to remove residual ions. method of exchange. 2. Ion exchange of vanadium-containing water, comprising a vanadium removal tower filled with zeolite, and an ion exchange tower provided after the vanadium removal tower and filled with a cation exchange resin layer and / or an anion exchange resin layer. apparatus.