JP2005329315A - Method and apparatus for recovering water from drainage containing tetraalkyl ammonium ion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for substantially completely adsorbing to remove a tetraalkyl ammonium ion (TAA ion) by an ion exchange resin regardless of the presence of coexistent ions and a pH of the drainage, and also easily regenerating the ion exchange resin after use when water is recovered from the drainage containing the TAA ions. <P>SOLUTION: Treated water cleard of the TAA ions is obtained by bringing the drainage containing the TAA ions into contact with a strong basic anion-exchange resin which mixes one form or more of an OH form, a bicarbonate form and a carbonate form, and thereafter bringing into contact with a weak acid cation-exchange resin. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method and apparatus for treating tetraalkylammonium (TAA) ion-containing wastewater, in particular, tetraalkylammonium hydroxide (TAAH) -containing wastewater in which a neutral salt such as NaCl coexists, and TAAH is neutralized, When some or all of them are present as neutral salts such as tetraalkylammonium chloride, and when TAA ion-containing wastewater shows acidity, TAA ions are removed from these wastewater and water is recovered. The present invention relates to a processing method and apparatus.

  For example, in the electronic industry field, the manufacturing process of semiconductor devices (LSI, VLSI, etc.), printed circuit boards, liquid crystal displays (LCD), flat panel displays such as plasma display panels (PDP), etc. includes a photolithography process. In this photolithography process, a photoresist film is formed on a substrate such as a wafer or a glass substrate, light is irradiated on a predetermined portion thereof, and then the unnecessary photoresist is dissolved with a developing solution to develop the resist. After forming a pattern and further performing a process such as etching, the insoluble resist film on the substrate is peeled off. In the development, TAAH such as tetramethylammonium hydroxide (hereinafter sometimes abbreviated as “TMAH”) or choline is generally used as an alkaline developer for the photoresist. In factories and laboratories that use these TAAHs, TAA ion-containing wastewater is discharged as development waste liquid and washing wastewater from development and subsequent washing processes. There are two types of photoresists: a positive type in which the exposed portion is soluble and a negative type in which the exposed portion is insoluble. Alkaline developer is the mainstream as a positive photoresist developer, and a negative photoresist developer. Organic solvent-based developers are the mainstream, but some use alkali developers.

  In such TAA ion-containing wastewater, as is clear from the above, TAA ions are usually in the form of an alkali with hydroxide ions as counter ions. Do not know, and in some cases may be neutralized or mixed with other waste water, at least a part of it must exist in the form of a salt with other types of ions as counter ions. There are many. Therefore, the counter ion of the TAA ion in the waste water containing TAA ions is not specified, and is captured by the concept of “ion”.

As a treatment method of such waste water containing TAA ions, <1> a method of adsorbing and removing TAA ions by contact with a weakly acidic cation exchange resin or a strongly acidic cation exchange resin, <2> an acrylic weakly acidic cation There is a method in which TAA ions are adsorbed and removed by passing water through an exchange resin.
JP-A-6-142649 JP-A-6-304557

<3> When treating the wastewater containing TAA ions, the TAA ion concentration is set to 0.15% by weight or less, and contact is made with at least one resin selected from strong acid cation exchange resins, weak acid cation exchange resins and chelate resins. There is also a method of adsorbing TAA ions.
JP 2000-126766 A

  Comparing both weakly acidic cation exchange resins and strongly acidic cation exchange resins have the following advantages and disadvantages. First, the weakly acidic cation exchange resin has an advantage that it can be easily regenerated with a regenerant after use, and TAA ions adsorbed on the resin can be easily eluted.

  However, the weakly acidic cation exchange resin has an effective pH range of 4 to 14, cannot be used at a pH of 4 or less, and has no neutral salt decomposition ability. Therefore, when there is no mineral acid ion of relatively strong acid such as chloride ion or sulfate ion in the waste water and TAA ion exists only in the form of alkali (TAAH) or weak acid salt such as carbonate, weakly acidic cation TAA ions can be removed even with an exchange resin, but when TAA ions are neutral salts with mineral acid ions such as Cl ions as counter ions, or when the pH of the wastewater is acidic, it can be almost removed. In addition, even when TAAH and a neutral salt such as NaCl coexist, the removal efficiency of TAA ions is very poor, and it is difficult to remove TAA ions substantially completely.

  In contrast, strong acidic cation exchange resins have a wide effective pH range of 0 to 14 and neutral salt resolution, so that TAA ions are neutral salts with mineral acid ions such as Cl ions as counter ions. It is possible to adsorb and remove TAA ions in the waste water even in the presence of neutral salts such as NaCl. However, strong acid cation exchange resins are expensive and impractical because they require a large amount of regenerant to elute and regenerate the adsorbed TAA ions. In addition, a method of combining a strongly acidic cation exchange resin after the weakly acidic cation exchange resin is also conceivable. However, in the case where a salt of TAA having a mineral acid ion as a counter ion is contained or in the presence of a neutral salt such as NaCl, Since TAA ions leaking from the weakly acidic cation exchange resin are adsorbed on the strongly acidic cation exchange resin, a large amount of regenerant is consequently required.

  As described above, in the method of recovering water from TAA ion-containing wastewater with an ion exchange resin, TAA ions are substantially completely adsorbed and removed by the ion exchange resin regardless of the presence of coexisting ions and the pH of the wastewater; and There was no method by which the ion exchange resin after use could be easily regenerated.

  Accordingly, an object of the present invention is to provide a method and an apparatus for recovering water from TAA ion-containing wastewater that has solved the above-mentioned drawbacks of the conventional methods.

  The present inventor contacts the wastewater containing tetraalkylammonium ions (TAA ions) with a strongly basic anion exchange resin in an OH form, a bicarbonate form, a carbonate form, or a mixture of these, and then weakens. It has been found that TAA ions can be removed substantially completely by using an acidic cation exchange resin without using a strong acidic cation exchange resin that is difficult to regenerate with a regenerant.

In order to construct an ion exchange method and apparatus that can remove TAA ions from waste water containing TAA ions substantially completely and that can easily regenerate the ion exchange resin, a weakly acidic cation exchange resin can be used. It is necessary to remove TAA ions. To that end, TAA ions and counter ions are formed by treating TAA ion-containing wastewater with a strongly basic anion exchange resin in the form of OH, bicarbonate or carbonate before the weakly acidic cation exchange resin. By replacing Cl ions from neutral salts such as NaCl in the wastewater and neutral salts coexisting in the wastewater with OH ions, bicarbonate ions or carbonate ions, the wastewater can be replaced with bases such as TAAH and NaOH, and / or It has been found effective to have a composition that substantially contains only weak acid salts such as Na ₂ CO ₃ and NaHCO ₃ .

  That is, in the present invention, the waste water containing tetraalkylammonium ions is brought into contact with a strongly basic anion exchange resin in one form of OH form, bicarbonate form and carbonate form or a mixture of two or more. The present invention provides a method for recovering water from a tetraalkylammonium ion-containing wastewater characterized by obtaining treated water from which tetraalkylammonium ions have been removed by contacting with a weakly acidic cation exchange resin.

  In addition, the present invention provides a strongly basic anion exchange resin having one or more of OH, bicarbonate and carbonate forms for passing water containing tetraalkylammonium ions. Anion exchange column loaded, and a cation loaded with a weakly acidic cation exchange resin for obtaining treated water from which tetraalkylammonium ions have been removed by passing the treated water obtained through the anion exchange column An apparatus for recovering water from tetraalkylammonium ion-containing wastewater, including an exchange tower, and a strong form in which one or more of OH, bicarbonate and carbonate forms are mixed A multilayer bed type ion having an anion exchange resin layer loaded with a basic anion exchange resin and a cation exchange resin layer loaded with a weakly acidic cation exchange resin located downstream thereof Tetraalkylammonium ion-containing wastewater is passed through the multilayer bed type ion exchange column to obtain treated water from which tetraalkylammonium ions have been removed. An apparatus for recovering water from alkylammonium ion-containing wastewater is provided. Here, as the strongly basic anion exchange resin in which two or more of OH type, bicarbonate type and carbonate type are mixed, for example, these ion forms are mixed in each resin particle and each resin fiber. In some cases, each ion-type resin may be mixed or laminated.

  The TAA ion in the present invention is tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, methyltriethylammonium hydroxide, trimethylethylammonium hydroxide, dimethyldiethyl hydroxide. Ammonium, trimethyl (2-hydroxyethyl) ammonium hydroxide (ie choline), triethyl (2-hydroxyethyl) ammonium hydroxide, dimethyldi (2-hydroxyethyl) ammonium hydroxide, diethyldi (2-hydroxyethyl) ammonium hydroxide , Methyl tri (2-hydroxyethyl) ammonium hydroxide, ethyl tri (2-hydroxyethyl) ammonium hydroxide, tetra (2-hydroxyethyl) ammonium hydroxide Derived beam or the like (especially the former two and choline) tetraalkyl ammonium hydroxide (TAAH).

The counter ions of TAA ions (TAA ⁺ ) in waste water containing TAA ions are usually hydroxide ions (OH ⁻ ) as described above, but depending on the factory, they may be mixed with other waste water. Since it may be neutralized and the liquidity may become acidic by mixing with other waste water, fluoride ion, chloride ion, bromide ion, sulfate ion, hydrogen sulfate ion, nitrate ion, phosphate ion, Generally, at least one selected from inorganic anions such as carbonate ion and hydrogen carbonate ion and organic anions such as formate ion, acetate ion and oxalate ion is at least a part of the counter ion of TAA ion. In many cases, TAAH and at least one salt of the anions listed above, for example, NaCl or Na ₂ SO ₄ coexist. The present invention is shown above by contacting TAA ion-containing wastewater with a strongly basic anion exchange resin in one of OH form, bicarbonate form and carbonate form or a mixture of two or more. By replacing OH ions, carbonate ions, and bicarbonate ions with anions having higher selectivity for ion exchange resins than OH ions, carbonate ions, and bicarbonate ions, the anions in the waste water And / or a composition containing substantially only a salt of a weak acid, and then contacted with a weakly acidic cation exchange resin to recover treated water from which TAA ions have been removed.

  TAA ion-containing wastewater is a photolithographic process in the manufacturing process of electronic components such as semiconductor devices (LSI, VLSI, etc.), printed circuit boards, flat panel displays such as liquid crystal displays (LCD) and plasma display panels (PDP). When TAAH is used as an alkaline developer of a photoresist, a TAA ion-containing developer waste solution or cleaning wastewater discharged from the development or washing process, and a TAAH-containing concentrated solution by electrodialysis or electrolysis of the TAA ion-containing developer waste solution are collected. The resulting desalted wastewater (demineralized water from which most of the TAA ions have been removed), the concentrated solution produced during the recovery of the TAAH-containing permeate by the NF membrane (nanofiltration membrane) separation treatment of the TAA ion-containing developer waste, and the TAA ion-containing developer Activated carbon treatment process for treating waste liquid and washing wastewater with activated carbon Neutralize the processing solution and development waste solution obtained through the process, and separate the insoluble photoresist (from the TAA salt-form photoresist to the acid form and become insoluble) by solid-liquid separation such as centrifugation or filtration. Treatment solution obtained through neutralization + solid-liquid separation step (acid as a neutralizing agent forms a salt with TAA ions), and neutralization + solid-liquid separation step, ozone, hydrogen peroxide Or it is desalted waste water etc. obtained when performing the organic substance decomposition | disassembly process by ultraviolet irradiation, and an electrolysis process, and collect | recovering TAAH containing concentrated liquids, However, The method of this invention is not limited to these, From any waste water containing TAA ion Applicable when collecting water.

The strongly basic anion exchange resin that can be used in the present invention can be used in the form of powder, granules, membranes, fibers, etc., but the granular resin has a processing efficiency (ion exchange capacity), It is preferable in terms of handleability and economy. Specific examples of the strongly basic anion exchange resin include Amberlite IRA400Cl, Amberlite IRA402BLCl, Amberlite IRA410Cl and Amberlite IRA900Cl manufactured by Rohm and Haas. These strongly basic anion exchange resins are made into an OH form with an alkali such as NaOH, a resin made into a bicarbonate form with a bicarbonate such as NaHCO ₃ or NH ₄ HCO ₃ , Na ₂ CO ₃ or (NH ₄ ) A resin formed into a carbonate form with a carbonate such as ₂ CO _3, a resin in which these ionic forms are mixed in each grain or fiber, or a mixture or lamination of these resins can be used.

  The weakly acidic cation exchange resin used in the present invention is a resin having a weak acid group such as an acrylic acid-based and / or methacrylic acid-based resin having a carboxylic acid group, and is usually crosslinked with divinylbenzene. Yes. It is not limited to gel type or MR type (macroreticular type), and the shape can be powder, granular, membrane, fiber, etc., but the processing efficiency (ion exchange capacity) ), A granular resin is preferable in terms of handling properties and economy. Basically, the material may be acrylic acid or methacrylic acid, and either may be used when the TAA ion concentration of the TAA ion-containing waste water is low. In the case of TAA ion-containing wastewater having a TAA ion concentration of more than 0.15% by weight, it is preferable to use an acrylic acid weakly acidic cation exchange resin from the viewpoint of strength (particularly strength against swelling shrinkage). Specific examples of the acrylic acid-based weakly acidic cation exchange resin include Amberlite IRC76 and Duolite C-476 manufactured by Rohm and Haas. Specific examples of the methacrylic acid-based weakly acidic cation exchange resin Examples include Amberlite IRC50 manufactured by Rohm and Haas, Diaion WK-10 manufactured by Mitsubishi Chemical Corporation, and the like.

  The present invention can be applied particularly advantageously to a TAA ion-containing wastewater having a relatively low TAA ion concentration. However, in the case of a relatively high concentration TAA ion-containing wastewater having a TAA ion concentration exceeding 0.15% by weight, Acrylic acid-based weakly acidic cation exchange resin is used, or whether the weakly acidic cation exchange resin is acrylic acid-based or methacrylic acid-based as described in JP-A-2000-126766. Dilute with water such as other waste water, recovered water or pure water so that the TAA ion concentration is 0.15 wt% or less, or permeate with a TAA ion concentration of 0.15 wt% or less by reverse osmosis membrane treatment. It is preferable to apply the present invention after making adjustments such as obtaining water. In this case, resin degradation such as irreversible swelling due to cracking or crushing of the resin due to large swelling and shrinkage due to repeated cycles of TAA ion adsorption and resin regeneration of the weakly acidic cation exchange resin, damage to the resin matrix structure, Can be reduced by alleviating the swelling. Further, by using the concentration of acid such as hydrochloric acid or sulfuric acid as a regenerant as 1 equivalent / L (liter, the same shall apply hereinafter) or less, the above-described resin deterioration can be further reduced by mitigating rapid shrinkage during regeneration. Can be reduced.

  In addition, an appropriate desalting treatment may be performed at a later stage in order to recover treated water having higher purity from the treated water from which TAA ions have been removed according to the present invention. For this purpose, for example, an ion exchange apparatus equipped with an ion exchange column (column) loaded with a strongly acidic cation exchange resin and / or a strongly basic anion exchange resin or a mixed or laminated resin thereof, an anode and a cathode A plurality of cation exchange membranes and anion exchange membranes are alternately arranged between these two electrodes to alternately form a desalting chamber and a concentration chamber, and the desalting chamber is filled with an ion exchange resin. A known demineralizer such as an electric deionizer having a configuration is used. In particular, it is preferable to use a mixed bed type cartridge polisher in which the above mixed resin is packed in a column (column). Examples of strongly basic anion exchange resins that can be used here include those listed above, and examples of strongly acidic cation exchange resins that can be used here include Rohm- And Amberlite IR120BH, Amberlite IR124H, Amberlite 200CTH, and Diaion SK1B and Diaion PK212 manufactured by Mitsubishi Chemical Corporation.

  As a method of contacting the TAA ion-containing wastewater or the treated water with various ion exchange resins, a conventionally known method may be appropriately used. For example, a column system in which ion exchange resin is loaded into a tower (column) and TAA ion-containing wastewater or its treated water is passed through, or powdered or granular ion exchange resin is added to TAA ion-containing wastewater or its treated water. A batch method in which the mixture is brought into contact with stirring, followed by filtration and solid-liquid separation can be employed.

  According to the present invention, tetraalkylammonium hydroxide (TAAH) -containing wastewater in which a neutral salt such as NaCl coexists, or TAAH is neutralized, and part or all of it as neutral salt such as tetraalkylammonium chloride. Even if it exists, or even if the TAA ion-containing wastewater shows acidity, it is a form in which one or more of OH, bicarbonate and carbonate forms are mixed in advance. By contacting with a strongly basic anion exchange resin, the waste water has a composition containing substantially only a base and / or a salt of a weak acid. By contacting this with a weakly acidic cation exchange resin, TAA ions are substantially contained. In addition, the treated water completely removed can be recovered, and the weakly acidic cation exchange resin after use can be easily regenerated.

  If necessary, the treated water from which TAA ions have been removed is further subjected to, for example, a strongly acidic cation exchange resin, a strongly basic anion exchange resin, or a strongly acidic cation exchange resin and a strongly basic anion exchange resin. The treated water with higher purity can be recovered by contacting with a mixed or laminated resin, or by treatment with an electric deionization device or a reverse osmosis membrane device.

  Next, the best mode for carrying out the invention will be described with reference to the drawings, but the present invention is not limited thereto.

  FIG. 1 is a flow diagram showing an example of the apparatus of the present invention for recovering water from TAA ion-containing wastewater, and this apparatus is composed of a multi-bed type ion exchange apparatus. That is, the anion exchange tower 1 and the cation exchange tower 3 are arranged in a separate tower system, and the anion exchange tower 1 has one or more of OH form, bicarbonate form and carbonate form. A strongly basic anion exchange resin 2 in a mixed form is loaded, and a cation exchange column 3 is loaded with a weakly acidic cation exchange resin 4. A TAA ion-containing wastewater storage tank (not shown) is passed through the line 5 through the TAA ion-containing wastewater tank to the anion exchange tower 1, and strong mineral acid ions such as chloride ions and sulfate ions coexist in the TAA-containing wastewater. It is adsorbed on the basic anion exchange resin 2. The obtained anion exchange treated water is sent to the cation exchange tower 3 through the line 6 and passed therethrough, and when the TAA ions are adsorbed on the weakly acidic cation exchange resin 4, the treated water from which the TAA ions have been removed through the line 7. Can be recovered. Of course, you may discharge this treated water depending on the case.

When the anion exchange tower 1 reaches its water flow end point (such as “end of treatment with a certain amount of water” or “breakthrough point”, and so on), the strongly basic ion exchange resin 2 loaded is regenerated. First, the valves (not shown) on the lines 5, 6, and 7 are closed to stop the flow of TAA ion-containing waste water. Open valves (not shown) on the lines 8 and 9, alkali such as NaOH, bicarbonate such as NaHCO ₃ and NH ₄ HCO ₃ , and carbonate such as Na ₂ CO ₃ and (NH ₄ ) ₂ CO _3. An aqueous solution of a regenerant selected from is passed through the anion exchange tower 1 and then washed with water such as (ultra) pure water to regenerate the strongly basic anion exchange resin 2.

  Similarly, when the cation exchange column 3 reaches the water flow end point, the loaded weak acid cation exchange resin 4 is regenerated. First, valves (not shown) on the lines 5, 6 and 7 are closed to stop the flow of TAA ion-containing waste water. Open valves (not shown) on the lines 10 and 11, pass an aqueous solution of a regenerant such as hydrochloric acid or sulfuric acid through the cation exchange tower 3, and then wash with water such as (ultra) pure water, and weakly acidic Regeneration of the cation exchange resin 4 is performed.

  FIG. 2 is a flow chart showing another example of the apparatus of the present invention for recovering water from TAA ion-containing wastewater, and this apparatus is composed of a multi-bed type ion exchange tower 21. That is, the anion exchange resin layer 22 and the cation exchange resin layer 23 are arranged in a laminated manner, and the anion exchange resin layer 22 has one or two of OH, bicarbonate, and carbonate forms. The above-mentioned strong basic anion exchange resin is loaded, and the cation exchange resin layer 23 is loaded with a weakly acidic cation exchange resin. A collector 24 for collecting the regenerated waste liquid is disposed between the ion exchange resin layers 22 and 23, and the regenerated waste liquid is discharged out of the system through a line 32. TAA ion-containing wastewater is passed through a line 27 from a TAA ion-containing wastewater storage tank (not shown) to the multi-layered ion exchange tower 21. First, chloride ions, sulfate ions, etc. coexisting in the TAA-containing wastewater. When mineral acid ions are adsorbed on the strongly basic anion exchange resin of the anion exchange resin layer 22 and then TAA ions are adsorbed on the weakly acidic cation exchange resin of the cation exchange resin layer 23, the TAA ions are removed. Treated water can be obtained.

  Although the apparatus of the present invention can be constituted only by the above-described multi-layer bed type ion exchange column 21, in the apparatus of FIG. A mixed bed type cartridge polisher 25 in which a mixed resin 26 of a strongly acidic cation exchange resin and a strongly basic anion exchange resin is packed in a column via a line 28 (non-regenerative type) is disposed. The treated water from which the TAA ions obtained from the multi-layer bed type ion exchange tower 21 have been removed is further purified by passing through the mixed bed type cartridge polisher 25, and the treated water having further increased purity is recovered through the line 29. (Of course, in some cases, this treated water may be discharged). This treated water can be used as (ultra) pure water, for example, as cleaning water in a photolithography process in the field of electronics industry. In place of the mixed bed type cartridge polisher 25, in some cases, one of a strongly acidic cation exchange resin and a strongly basic anion exchange resin, a laminated resin of both, a strong acid cation exchange resin, Of course, it is possible to use a separate bed type demineralizer in which a strong basic anion exchange resin is packed in each column and arranged in series, or the above-described electric deionizer may be used.

When the anion exchange resin layer 22 and / or the cation exchange resin layer 23 of the multi-layer bed type ion exchange tower 21 reach the water flow end point, the valves (not shown) on the lines 27, 28, and 29 are closed, and the TAA ions The flow of the contained wastewater is stopped, and the strong base anion exchange resin of the anion exchange resin layer 22 and / or the weakly acidic cation exchange resin of the cation exchange resin layer 23 is regenerated. When regeneration of both ion exchange resins is performed simultaneously, valves (not shown) on the lines 30, 31, and 32 are opened, and from the line 30, alkalis such as NaOH, bicarbonates such as NaHCO ₃ and NH ₄ HCO ₃ are used. , And an aqueous solution of a regenerant selected from carbonates such as Na ₂ CO ₃ and (NH ₄ ) ₂ CO ₃ are passed down the anion-exchange resin layer 22 and at the same time, hydrochloric acid, sulfuric acid, etc. The aqueous solution of the acid regenerant is passed through the cation exchange resin layer 23 in an upward flow, and then both layers are washed with water such as (ultra) pure water to regenerate both ion exchange resins. The recycled waste liquid is collected in the collector 24 and discharged out of the system through the line 32.

Regeneration of the anion exchange resin layer 22 and the cation exchange resin layer 23 of the multilayer bed type ion exchange tower 21 can also be performed individually. When the anion exchange resin layer 22 is regenerated, an alkali such as NaOH, a bicarbonate such as NaHCO ₃ or NH ₄ HCO ₃ , and Na ₂ CO ₃ or (NH ₄ ) ₂ CO ₃ are used from the line 30. At the same time, an aqueous solution of a regenerant selected from carbonates of the above is passed through the anion exchange resin layer 22 in a downward flow, and at the same time, (super) pure water is passed through the line 31 in an upward flow, and then The anion exchange resin layer 22 is regenerated by washing with pure water or the like, and the regenerated waste liquid is collected by the collector 24 and discharged out of the system through the line 32. When the cation exchange resin layer 23 is regenerated, an aqueous solution of an acid regenerant such as hydrochloric acid or sulfuric acid is passed through the cation exchange resin layer 23 from the line 31 and simultaneously from the line 30 ( Ultra) pure water or the like is passed in a downward flow, and then the cation exchange resin layer 23 is washed with water such as (ultra) pure water to regenerate the cation exchange resin layer 23. The water is collected and discharged through the line 32 to the outside of the system.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to comparative examples, but the present invention is not limited to the examples.

A 400% 4% NaOH aqueous solution was passed through a column packed with 200 ml of strongly basic anion exchange resin IRA402BLCl, and then washed with pure water to obtain a strongly basic anion exchange resin in the OH form. A simulated wastewater having a tetramethylammonium hydroxide concentration of 10 mg CaCO ₃ / L and a NaCl concentration of 50 mg CaCO ₃ / L was passed through this OH-type strongly basic anion exchange resin column at LV ₃₀ m / h as raw water. Next, the obtained anion exchange treated water was passed through a column packed with 200 ml of H-form weakly acidic cation exchange resin IRC76 at LV 30 m / h, and the TMA ion concentration of the obtained treated water was measured. The results are shown in Table 1. The unit of the numerical value of the TMA ion concentration in Table 1 is mgCaCO ₃ / L.

A column packed with 200 ml of strongly basic anion exchange resin IRA402BLCl was passed through 800 ml of 2% NaHCO ₃ solution, and then washed with pure water to make the strongly basic anion exchange resin into a bicarbonate form. A simulated wastewater having a tetramethylammonium hydroxide concentration of 5 mg CaCO ₃ / L and a tetramethylammonium chloride concentration of 5 mg CaCO ₃ / L was passed through the column of the bicarbonate type strongly basic anion exchange resin as raw water at LV 30 m / h. Next, the obtained anion exchange treated water was passed through a column packed with 200 ml of H-form weakly acidic cation exchange resin IRC76 at LV 30 m / h, and the TMA ion concentration of the treated water was measured. The results are shown in Table 1.

Comparative Example 1
The same treatment as in Example 1 was performed except that the simulated waste water was passed through only the weakly acidic cation exchange resin column without passing through the strongly basic anion exchange resin column. The results are shown in Table 1.

Comparative Example 2
The same treatment as in Example 2 was performed except that the simulated waste water was passed through only the weakly acidic cation exchange resin column without passing through the strongly basic anion exchange resin column. The results are shown in Table 1.

  According to the present invention, high-purity water can be recovered from the TAA ion-containing wastewater, so that the recovered water can be used as miscellaneous water, process water, and the like. It is also possible to recover water of higher purity by treatment and reuse it. Therefore, in the electronic industry field, a photolithography process using TAAH as a developer in the manufacturing process of semiconductor devices (LSI, VLSI, etc.), printed circuit boards, flat panel displays such as liquid crystal displays (LCD) and plasma display panels (PDP). The method and apparatus of the present invention can be applied to TAA ion-containing wastewater discharged from water and other TAA ion-containing wastewater.

FIG. 1 is a flowchart showing an example of the apparatus of the present invention for recovering water from TAA ion-containing wastewater. FIG. 2 is a flow diagram showing another example of the apparatus of the present invention for recovering water from TAA ion-containing wastewater.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Anion exchange tower 2 Strongly basic anion exchange resin 3 Cation exchange tower 4 Weakly acidic cation exchange resin 21 Double layer bed type ion exchange tower 22 Strongly basic anion exchange resin 23 Weakly acidic cation exchange resin 25 Mixed Floor type cartridge polisher

Claims (5)

  Tetraalkylammonium ion-containing wastewater is brought into contact with a strongly basic anion exchange resin in the form of OH, bicarbonate and carbonate, or a mixture of two or more, followed by a weakly acidic cation exchange resin. A method for recovering water from tetraalkylammonium ion-containing wastewater, wherein treated water from which tetraalkylammonium ions have been removed is obtained by contacting with water.   The treated water from which tetraalkylammonium ions have been removed is obtained by further desalting the treated water from which the tetraalkylammonium ions have been removed, to recover water from the tetraalkylammonium ion-containing wastewater according to claim 1. how to.   Anion exchange column loaded with strong basic anion exchange resin in the form of OH, bicarbonate and carbonate, or a mixture of two or more, for passing wastewater containing tetraalkylammonium ions And a cation exchange column loaded with a weakly acidic cation exchange resin for obtaining treated water from which tetraalkylammonium ions have been removed by passing the treated water obtained through the anion exchange column. An apparatus for recovering water from tetraalkylammonium ion-containing wastewater.   An anion exchange resin layer loaded with a strongly basic anion exchange resin in the form of OH, bicarbonate and carbonate, or a mixture of two or more, and weak acidity located downstream A multilayer bed type ion exchange tower having a cation exchange resin layer loaded with a cation exchange resin, and water containing tetraalkylammonium ions is passed through the multilayer bed type ion exchange tower to generate tetraalkylammonium ions. An apparatus for recovering water from tetraalkylammonium ion-containing wastewater, wherein the apparatus is configured to obtain removed treated water.   The tetrahydrochloric acid according to claim 3 or 4, further comprising a desalting apparatus for obtaining treated water with further increased purity by passing the treated water from which the tetraalkylammonium ions have been removed. A device that collects water from wastewater containing alkylammonium ions.

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