JP2012210565A - Apparatus and method for regenerating development waste liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably and efficiently carry out long-term regeneration treatment of a development waste liquid that contains resist exfoliation and tetraalkylammonium hydroxide (TAAH).SOLUTION: Acid is added to the development waste liquid containing resist exfoliation and TAAH to adjust the liquid to pH 8-9.5, and then membrane separation treatment is carried out by an MF membrane module 1. A permeated liquid is subjected to membrane separation treatment at a liquid permeation temperature of 40-80°C by a nanofiltration (NF) membrane module 2 with a molecular weight cutoff of 200-900 and treated in an activated carbon column 3. Setting the liquid permeation temperature of the NF membrane to 40-80°C lowers the viscosity of the treated liquid and suppresses an operating pressure to increase the amount of permeated liquid. When the amount of permeated liquid of the NF membrane is increased, the resist exfoliation leaks to the permeated liquid side of the NF membrane. However, since the resist exfoliation can be eliminated in the activated carbon treatment in a subsequent stage, a regenerated liquid of high TAAH purity can be obtained.

Description

  The present invention relates to an apparatus and method for regenerating a developing waste liquid that regenerates a developing waste liquid containing tetraalkylammonium hydroxide (hereinafter referred to as “TAAH”) generated in the process of manufacturing electronic components such as semiconductors, liquid crystals, and printed circuit boards.

  Conventionally, when manufacturing electronic parts such as semiconductors, liquid crystals, and printed circuit boards, a negative or positive photoresist film is formed on a substrate such as a Si wafer, and then light or the like is passed through the resist film through a pattern mask. A method is employed in which an unnecessary photoresist is dissolved and removed using a developer, and an insoluble photoresist film on the substrate is peeled off after further processing such as etching. Since the TAAH aqueous solution is usually used as the developer, a developing waste solution containing a resist strip and TAAH is discharged from such a development step in the field of manufacturing electronic components.

  TAAH-containing photoresist development wastewater is a large amount of discharge, and since TAAH nitrogen causes water pollution, it cannot be discarded as it is, but it may be disposed of by reducing the volume and reducing the amount of waste. Generally, impurities in the waste liquid are removed, purified and reused.

Conventionally, as a method for regenerating a TAAH-containing developer waste solution, Patent Documents 1 and 2 propose a membrane separation method using a nanofiltration (NF) membrane.
Specifically, in Patent Document 1, a process of adjusting the development waste liquid to pH 9.5 to 12 and separating with an NF membrane is performed. When carbonic acid is used for this pH adjustment, carbonic acid is CO ₃ ^{2. In the} presence of such divalent ions, there is a problem that the amount of permeated liquid of the NF membrane rapidly decreases.
Further, Patent Document 2 discloses a method of processing using an alkali-resistant NF film. However, when processing a development waste liquid having a TAAH concentration of 10% by weight or more, the osmotic pressure and viscosity are determined from the liquid properties. In order to ensure a high and constant amount of water, the operating pressure needs to be 2.0 MPa or more. The high-pressure treatment of the alkaline developer waste solution in this way has a problem of safety and an increase in equipment cost.

  Patent Document 3 discloses a method of treating a development waste liquid with activated carbon. However, the developing waste liquid usually contains about 0.1 to 1 g / L of the resist stripped material. When the developing waste solution containing the resist stripped material at such a high concentration is directly treated with activated carbon, the activated carbon is in an early stage. Therefore, enormous amounts of activated carbon are required, which is not practical.

Japanese Patent No. 3671644 Japanese Patent No. 3497841 JP 58-30753 A

  An object of the present invention is to solve the above-mentioned conventional problems and to provide an apparatus and method for stably and efficiently regenerating a development waste solution containing a resist strip and TAAH over a long period of time.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have preferably treated the permeate obtained by membrane separation treatment of the development waste liquid with a predetermined fractional molecular weight prior to the activated carbon treatment. It has been found that the above-mentioned problems can be solved by performing a two-stage membrane separation treatment using the NF membrane as a subsequent separation membrane, and more preferably by raising the liquid passing temperature of the NF membrane.

  The present invention has been achieved on the basis of such findings, and the gist thereof is as follows.

[1] In a recycling apparatus for developing waste liquid containing a resist strip and a tetraalkylammonium hydroxide,
PH adjusting means for adjusting the pH to 8 to 9.5 by adding an acid to the developing waste solution;
first membrane separation means for membrane separation treatment of pH adjusted developer waste,
An apparatus for regenerating waste developer, comprising: an activated carbon tower through which the permeate of the membrane separation means is passed.

[2] In [1], the membrane separation unit performs a membrane separation process on a first membrane separation unit that performs a membrane separation process on the pH-adjusted developer waste liquid, and a membrane separation process on a permeate liquid of the first membrane separation unit. And a membrane separation means, wherein the permeate of the second membrane separation means is passed through the activated carbon tower.

[3] In [1] or [2], the separation membrane of the second membrane separation means is a nanofiltration membrane having a fractional molecular weight of 200 to 900, and membrane separation treatment is performed at a liquid passing temperature of 40 to 80 ° C. A developing waste liquid recycling apparatus characterized by being performed.

[4] An apparatus for recycling a developing waste liquid according to [2] or [3], wherein the separation membrane of the first membrane separation means is a microfiltration membrane having a pore diameter of 1 μm or less.

[5] The apparatus for regenerating waste developer according to [2] or [3], wherein the separation membrane of the first membrane separation means is an ultrafiltration membrane having a fractional molecular weight of 100,000 or less.

[6] The developing waste liquid regenerating apparatus according to any one of [1] to [5], wherein the activated carbon tower is a non-regenerating activated carbon tower.

[7] In any one of [2] to [6], the measurement means for measuring the absorbance of the permeate of the first membrane separation means, and the cleaning timing of the second membrane separation means based on the measured absorbance. An apparatus for regenerating development waste liquid, comprising: a cleaning control means for determining.

[8] In a method for regenerating a developing waste solution containing a resist strip and a tetraalkylammonium hydroxide,
A pH adjusting step of adjusting the pH to 8 to 9.5 by adding an acid to the developing waste solution;
a membrane separation step for membrane separation treatment of pH adjusted developer waste,
A method for regenerating a developing waste liquid, comprising: an activated carbon treatment step for treating a permeate in the membrane separation step.

[9] In [8], in the membrane separation step, a first membrane separation step for membrane separation treatment of the pH-adjusted developer waste solution, and a membrane separation treatment for the permeate in the first membrane separation step. And a membrane separation step, wherein the permeate in the second membrane separation step is treated in the activated carbon treatment step.

[10] In [8] or [9], the separation membrane in the second membrane separation step is a nanofiltration membrane having a fractional molecular weight of 200 to 900, and a membrane separation treatment at a liquid passing temperature of 40 to 80 ° C. A method for regenerating a developing waste solution, wherein:

[11] The method for regenerating a developing waste liquid according to [9] or [10], wherein the separation membrane in the first membrane separation step is a microfiltration membrane having a pore diameter of 1 μm or less.

[12] The method for regenerating a developing waste liquid according to [9] or [10], wherein the separation membrane in the first membrane separation step is an ultrafiltration membrane having a fractional molecular weight of 100,000 or less.

[13] The method for regenerating a developing waste liquid according to any one of [8] to [12], wherein a non-regenerating type activated carbon tower is used in the activated carbon treatment step.

[14] In any one of [9] to [13], the absorbance of the permeate in the first membrane separation step is measured, and the separation membrane is washed in the second membrane separation step based on the measured absorbance. A method for regenerating a developing waste liquid, characterized in that the timing is determined.

  According to the present invention, the lifetime of the activated carbon can be extended by performing the membrane separation treatment prior to the activated carbon treatment. Further, in the membrane separation treatment, there is no need to perform advanced membrane separation because there is an activated carbon treatment in the subsequent stage, and it becomes easy to secure a permeate.

In particular, in a preferred embodiment of the present invention, the developing waste liquid can be treated and regenerated stably and efficiently over a long period of time based on the following effects.
(1) By adjusting the developing waste liquid to pH 8 to 9.5, the resist stripped material in the developing waste liquid can be deposited and removed by membrane separation.
(2) By using a NF film having a molecular weight cut off of 200 to 900, it is possible to efficiently remove the resist stripped material without removing TAAH.
(3) By setting the liquid passing temperature of this NF membrane to 40 to 80 ° C., the viscosity of the liquid to be treated can be lowered and the amount of permeated liquid can be increased without excessively increasing the operating pressure.
(4) When the permeate temperature of the NF membrane is increased to 40 to 80 ° C. and the amount of permeate is increased, the resist exfoliation leaks to the permeate side of the NF membrane. And a regenerated solution with high TAAH purity can be obtained.
In the NF membrane permeate used for this activated carbon treatment, the resist stripped material has already been sufficiently removed, so that the activated carbon does not break through early.

1 is a system diagram showing an embodiment of a developing waste liquid recycling apparatus of the present invention. FIG. 10 is a graph showing changes over time in absorbance of a treatment liquid in Comparative Example 3.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a system diagram showing an embodiment of a developing waste liquid regenerating apparatus according to the present invention. In FIG. 1, 1 is a microfiltration (MF) membrane module, 2 is an NF membrane module, 3 is an activated carbon tower, 4 Is a recovered raw water tank, 5 is a permeate tank, and P ₁ and P ₂ are pumps.

In the reproducing apparatus 1, a developing waste liquid after the acid is added has been adjusted to a predetermined pH, by the pump P ₁ through the collecting raw water tank 4 MF membrane module 1 (the first membrane separation unit, a first Membrane separation process) and membrane separation treatment. A part of the concentrated liquid of the MF membrane module 1 is discharged out of the system as a concentrated waste liquid, and the remaining part is returned to the recovery raw water tank 4 and circulated.

The permeate of the MF membrane module 1 is introduced into the NF membrane module (second membrane separation means / second membrane separation step) 2 by the pump P ₂ through the permeate tank 5 and subjected to membrane separation treatment.
A part of the concentrated liquid of the NF membrane module 2 is discharged out of the system as a concentrated waste liquid, and the remaining part is returned to the permeate tank 5 and circulated.

  The permeated liquid of the NF membrane module 2 is introduced into the activated carbon tower 3 and treated with activated carbon, and the effluent is recovered as a treated liquid (regenerated liquid).

  The developing waste liquid to be treated in the present invention contains TAAH and resist strips generated in the process of manufacturing electronic parts such as semiconductors, liquid crystals, and printed circuit boards. The developing waste liquid includes not only the developing waste liquid during development but also the cleaning waste liquid discharged in the subsequent cleaning process.

  TAAH contained in the developing waste liquid includes tetramethylammonium hydroxide (hereinafter referred to as “TMAH”), tetraethylammonium hydroxide (hereinafter referred to as “TEAH”), tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide. , Diethyldimethylammonium hydroxide, trimethyl (2-hydroxyethyl) ammonium hydroxide, triethyl (2-hydroxyethyl) ammonium hydroxide, dimethyldi (2-hydroxyethyl) ammonium hydroxide, diethyldi (2-hydroxyethyl) ammonium hydroxide , Methyltri (2-hydroxyethyl) ammonium hydroxide, ethyltri ( - hydroxyethyl) ammonium hydroxide, tetra (2-hydroxyethyl) but one or more of such ammonium hydroxide and the like, usually, TMAH, or TEAH is used.

  Usually, the developing waste liquid to be processed in the present invention has a strong alkalinity of about 12 to 14% in pH with these TAAH concentrations of about 1 to 20% by weight and resist strips of about 0.01 to 10 g / L. When the concentration of TAAH in the development waste liquid and the cleaning waste liquid discharged from the development step is lower than the above range, the TAAH concentration may be concentrated by an evaporator or the like and processed according to the present invention.

  In the present invention, an acid is added to such a developing waste solution to adjust the pH to 8 to 9.5, thereby insolubilizing and depositing the resist strip dissolved in the developing waste solution. If the adjusted pH value is higher than 9.5, the resist stripped material is not sufficiently precipitated, and even if the pH is lower than 8.5, no further effect of depositing the resist stripped material can be obtained. The amount of addition is excessively undesirable.

  As the acid used for pH adjustment, carbon dioxide and / or carbonic acid is preferable. Inorganic acids such as hydrochloric acid, sulfuric acid, and nitric acid are not preferable because inorganic anions such as chlorine ions, sulfate ions, and nitrate ions remain and adversely affect the semiconductor device and the like when the regenerated solution is reused.

  Examples of the material of the MF membrane of the MF membrane module 1 for membrane separation treatment of pH adjusted developer waste include polysulfone, polyvinylidene fluoride (PVDF), polyethylene (PE), polyvinyl chloride (PVC), and ceramics. When the permeated liquid amount of the membrane decreases, the membrane is washed with a strong alkaline washing liquid having a pH of 13 or higher, and therefore, alkali-resistant polysulfone and polyethylene are preferable.

  Moreover, since the resist stripped product is usually particles having a particle size of about 0.5 to 10 μm, the pore size of the MF membrane is 1 μm or less, particularly 0.02 to 0.1 μm, so that the amount of permeate can be maintained. In addition, it is preferable for efficiently removing the deposited particles of such a resist strip.

  As the first membrane separation means, an ultrafiltration (UF) membrane module may be used in addition to the MF membrane module shown in FIG. In this case, a lot of dissolved resist strips that do not precipitate even if the development waste liquid is adjusted to pH 9.5 or less remain, and the development waste liquid contains organic substances such as surfactants in addition to the resist strips. Therefore, in order to remove these efficiently, when a UF membrane having a molecular weight cut-off of 100,000 or less, preferably 13000 or less, for example, about 1000 to 13000 is used, the load of the NF membrane in the subsequent stage is reduced and the NF membrane is reduced. The module can be stably operated, which is preferable.

There are no particular restrictions on the liquid flow conditions in the first membrane separation means such as the MF membrane module 1, but the following conditions are preferred.
Operating pressure: 0.01-0.15 MPa
Recovery rate: 85-95%
Circulating water volume: 2-5 times the treated water Temperature: 20-40 ° C

  Since the material of the NF membrane module 2 of the NF membrane module 2 that performs membrane separation treatment of the permeate of the MF membrane module 1 needs to be washed with a strong alkaline washing solution having a pH of 13 or higher, it is resistant to alkali such as polysulfone and polyethersulfone. Is preferred.

  In this NF membrane module 2, it is preferable to use an NF membrane having a fractional molecular weight of 200 to 1200, particularly about 200 to 800 in order to allow TAAH to permeate and remove impurities other than TAAH. If the molecular weight cutoff of the NF film is less than 200, TAAH cannot be transmitted, and if it is greater than 900, impurities such as resist strips cannot be removed sufficiently.

  As the alkali-resistant NF film having such a molecular weight cut off, for example, “MPS-34” manufactured by Koch, “NPO30” manufactured by Nadia, and the like can be used.

  As described above, when processing a developing waste liquid containing 10% by weight or more of TAAH, the osmotic pressure and viscosity are high due to its liquid properties, and the operation pressure is at least 2.0 MPa when trying to ensure a constant amount of permeate. In addition, the filtration resistance is high even when the operation pressure is increased, and a large membrane area may be required.

  Therefore, in the present invention, the membrane separation treatment is preferably performed with the liquid passing temperature of the NF membrane module 2 being 40 to 80 ° C., preferably 50 to 60 ° C. By increasing the liquid passing temperature in this way, the viscosity of the liquid to be treated is lowered, and a sufficient amount of permeated liquid can be secured.

  In addition, although the leak to the permeate side of a small amount of resist stripped material is observed due to the increase in the amount of the permeated liquid, in the present invention, the leaked resist stripped material can be removed by the activated carbon tower 3 in the subsequent stage. Therefore, the leaked resist strip does not become a problem.

There are no particular restrictions on the conditions for passing the liquid in the NF membrane module 2, but the following conditions are preferred. In particular, the operating pressure can be lowered by increasing the liquid passing temperature, and the stability, equipment It is preferable in terms of cost.
Operating pressure: 2.8 to 3.8 MPa
Recovery rate: 75-85%
Circulating water volume: 1 to 100 times the treated water Temperature: 40 to 70 ° C

  The activated carbon of the activated carbon tower 3 that treats the permeated liquid of the NF membrane module 2 may be either coconut shell-based or coal-based, and the shape thereof may be any shape such as granular, sheet, or the like.

If the SV passing through the activated carbon tower 3 is excessively high, the effect of removing the residual resist stripped material is low, and if it is excessively low, the processing efficiency decreases, so that it is 5 to 40 h ⁻¹ , particularly 10 to 20 h ^−1. preferable.

  The activated carbon used in the treatment can be regenerated with steam or alkaline chemicals on site, but there is a concern of contamination due to regeneration, so use a non-regenerative type that is replaced after passing through for a certain period of time. It is preferable. In the present invention, even when a non-regenerative type activated carbon tower is used, since the resist stripped material in the development waste liquid is sufficiently removed by the membrane separation treatment in the previous stage of the activated carbon tower, the activated carbon tower The exchange frequency is not a problem.

  In the present invention, the separation membrane used for the membrane separation treatment of the development waste liquid needs to be washed periodically or when necessary when the permeate amount decreases. In particular, the NF membrane in the latter stage has a relatively small molecular weight cut and the permeate amount is likely to decrease. However, it takes time to recover the membrane performance in the cleaning after the membrane clogging has progressed, and is constant. Periodic cleaning for each period cannot cope with the progress of film contamination due to changes in the liquid properties of the liquid to be processed and changes in processing conditions.

  Therefore, it is desirable to detect an appropriate cleaning time of the NF film and perform cleaning with an appropriate cleaning frequency before the film clogging progresses and without excessively increasing the cleaning frequency.

  Therefore, in the developing waste solution regenerating apparatus as shown in FIG. 1, the absorbance of the permeate of the MF membrane module 1 which is the first membrane separation means is measured with an absorption spectrophotometer (absorptiometer). Therefore, it is preferable to set the cleaning time or the cleaning frequency of the NF membrane module 2 as the second membrane separation means. That is, the property of the permeate of the MF membrane module 1 of the first membrane separation means introduced into the NF membrane module 2 as the second membrane separation means affects the progress of the membrane contamination of the NF membrane module 2. The properties of the permeated liquid of the MF membrane module 1 are sufficiently reflected in the absorbance. Permeated water having a low absorbance hardly contaminates the NF membrane, and permeated water having a high absorbance tends to contaminate the NF membrane. Therefore, it is preferable to control the washing frequency based on the measurement result of the absorbance.

  That is, for example, an absorption spectrophotometer (absorptiometer) is provided in a pipe for supplying the permeate from the permeate tank 5 to the NF membrane module 2, and the absorbance at a wavelength of 290 to 500 nm, specifically, a wavelength of 450 nm is measured. A method for setting the cleaning time or the cleaning frequency of the NF membrane module 2 as follows.

(1) The relationship between the absorbance and the washing frequency is programmed in advance, and the washing frequency corresponding to the measured absorbance is adopted.
(2) When the absorbance measurement value tends to increase, the cleaning frequency is increased, and when the absorbance measurement value tends to decrease, the cleaning frequency is decreased.
(3) If the measured value of absorbance exceeds the set value, wash immediately or within a predetermined period.

In the membrane cleaning, the flow of the developing waste liquid is stopped, the cleaning liquid is injected into the NF membrane module for a certain period of time for cleaning, and after the cleaning, the processing of the developing waste liquid is started again.
The pH of the cleaning liquid is preferably pH 12.5 or more, particularly preferably pH 13.5 or more.

  The above-described absorbance measurement and cleaning can be performed automatically without requiring manual operation, and the NF membrane module can be cleaned at an optimal cleaning frequency and stably operated automatically.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.
In the following, as a sample solution, a TMAH-containing developing waste solution (pH 14 or more, TMAH concentration 12 wt%, resist exfoliation content 3 g / L) discharged from the semiconductor manufacturing process and concentrated about 6 times was used.
In the following, the concentrated liquid amount and permeated liquid amount of the separation membrane indicate the amount of liquid per separation membrane element.

The absorbance of the liquid was measured with a spectrophotometer “U-2810” manufactured by Hitachi, Ltd. at a wavelength of 450 nm.
The turbidity was measured with a turbidimeter “2100P” manufactured by HACH, and the TMAH concentration was measured by neutralization titration using a bromocresol green / methyl red indicator.

[Comparative Example 1]
(1) Test method The pH of the sample solution was adjusted to 9.0 using carbonic acid, and the following conditions were applied to an NF membrane (4 inch element manufactured by Koch (MPS34-4040, fractional molecular weight 200, material polyethersulfone)). The membrane separation treatment was performed by passing the solution through.

<Liquid flow conditions>
Liquid temperature: 30 ° C
Operating pressure: 3.0 MPa
Concentrated liquid circulation rate: 1.5 m ³ / h
Permeate volume: Decrease gradually from 3 L / h at the start of membrane separation. Recovery: 50%

(2) Test results At the initial stage of liquid passage, the amount of permeated liquid was 3 L / h, and the permeated liquid disappeared completely after 12 hours of liquid passage, and did not reach the expected value of 15 L / h or more at all.

[Comparative Example 2]
(1) Test method The pH of the sample solution was adjusted to 9.0 using carbonic acid, and an NF membrane (4 inch element (MPS36-4040, fractional molecular weight 1000, material polyethersulfone) manufactured by Koch) was used as Comparative Example 1. The liquid was passed under the same conditions.
The absorbance of the sample solution after pH adjustment was 0.4.

(2) Test results The amount of permeated liquid was 70 L / h, but the absorbance of the permeated liquid was 0.35 compared to the absorbance at the entrance of the NF membrane of 0.45. could not.

[Comparative Example 3]
(1) Test method The pH of the sample solution was adjusted to 12.0 using carbon dioxide (absorbance 0.4), and the solution was passed through the following activated carbon tower under the following solution flow conditions.

<Activated carbon tower>
"Carboner CF50" manufactured by Kurita Kogyo Co., Ltd. (Amount of activated carbon: 50L)
Activated carbon: Coconut shell system 10-32
<Liquid flow conditions>
Water flow SV: 5h ^-1
Water flow rate: 0.25m ³ / h

(2) Test results FIG. 1 shows the relationship between the number of days of liquid passage and the absorbance of the treatment liquid (the effluent of the activated carbon tower).
As is clear from FIG. 1, the absorbance of the treatment liquid was maintained at 0.1 or less until 3 days after the start of liquid flow, but the absorbance increased thereafter, resulting in breakthrough.

[Comparative Example 4]
(1) Test method The pH of the sample solution was adjusted to 9.0 using carbonic acid, and the following MF membrane and NF membrane were used, and liquid was passed in the following order in the order of MF membrane → NF membrane (that is, Then, the permeate of the MF membrane is passed through the NF membrane.) The liquid passing temperature was 30 ° C.

<MF membrane>
Asahi Kasei internal pressure hollow fiber membrane PSP-303
Material: Polyethylene Nominal pore size: 0.1 μm
Size: 89 x 1129mm
Membrane area: 6.0 m ²
Operating pressure: 0.05 MPa
Recovery rate: 90%

<NF film>
4 inch element MPS34-4040 made by Koch
Material: Polyethersulfone Fractionated molecular weight: 200
Concentrated liquid circulation rate: 1.5 m ³ / h
Operating pressure: 3.0 MPa
Recovery rate: 75%

(2) Test results Table 1 shows the results of water quality analysis of the sample solution, MF membrane permeate, and NF membrane permeate after pH adjustment.

  As is clear from Table 1, the NF membrane permeate satisfied the target concentration, but the amount of permeate through the NF membrane after passing through for 12 hours was 10 L / h, and did not reach the expected value.

[Example 1]
(1) Test method In Comparative Example 4, the treatment temperature was set to 50 ° C., and as shown in FIG. 1, the NF membrane permeate was further passed through the following activated carbon tower under the following conditions. Went.

<Activated carbon tower>
"Carboner CF50" manufactured by Kurita Kogyo Co., Ltd. (Amount of activated carbon: 100L)
Activated carbon: Coconut shell system 10-32
<Liquid flow conditions>
Water flow SV: 10h ^-1
Water flow rate: 1.0m ³ / h

(2) Test results Table 2 shows the results of water quality analysis of the sample solution, MF membrane permeate, NF membrane permeate, and activated carbon tower effluent after pH adjustment.

As apparent from Table 2, the NF membrane permeate did not reach the target absorbance <0.1, but the absorbance <0.1 was stably satisfied by installing an activated carbon tower.
Further, the permeated liquid amount of the NF membrane after passing through for 12 hours was 17 L / h, which satisfied the expected value.
The liquid passing treatment was continuously performed for 3 months under these conditions, but the absorbance of the activated carbon tower effluent stably achieved <0.1.

1 MF membrane module 2 NF membrane module 3 Activated carbon tower 4 Recovery raw water tank 5 Permeate tank

Claims (14)

In a recycling apparatus for developing waste liquid containing a resist strip and tetraalkylammonium hydroxide,
PH adjusting means for adjusting the pH to 8 to 9.5 by adding an acid to the developing waste solution;
first membrane separation means for membrane separation treatment of pH adjusted developer waste,
An apparatus for regenerating waste developer, comprising: an activated carbon tower through which the permeate of the membrane separation means is passed.   2. The first membrane separation unit according to claim 1, wherein the membrane separation unit performs a membrane separation process on the pH-adjusted developer waste liquid, and a second membrane performs a membrane separation process on the permeate of the first membrane separation unit. And a separation means, wherein the permeate of the second membrane separation means is passed through the activated carbon tower.   3. The separation membrane according to claim 1 or 2, wherein the separation membrane of the second membrane separation means is a nanofiltration membrane having a fractional molecular weight of 200 to 900, and the membrane separation treatment is performed at a liquid passing temperature of 40 to 80 ° C. Development waste liquid recycling device.   4. A developing waste liquid recycling apparatus according to claim 2, wherein the separation membrane of the first membrane separation means is a microfiltration membrane having a pore diameter of 1 μm or less.   4. The recycling apparatus for developing waste liquid according to claim 2, wherein the separation membrane of the first membrane separation means is an ultrafiltration membrane having a fractional molecular weight of 100,000 or less.   6. The recycling apparatus for developing waste liquid according to claim 1, wherein the activated carbon tower is a non-regenerative activated carbon tower.   7. The method according to claim 2, wherein the absorbance of the permeated liquid of the first membrane separation unit is measured, and the cleaning time for determining the cleaning time of the second membrane separation unit is determined based on the measured absorbance. And a developing device for recycling a developing waste liquid. In a method for regenerating a waste developer containing a resist strip and a tetraalkylammonium hydroxide,
A pH adjusting step of adjusting the pH to 8 to 9.5 by adding an acid to the developing waste solution;
a membrane separation step for membrane separation treatment of pH adjusted developer waste,
A method for regenerating a developing waste liquid, comprising: an activated carbon treatment step for treating a permeate in the membrane separation step.   9. The membrane separation step according to claim 8, wherein the membrane separation step includes a first membrane separation step for membrane separation treatment of the pH-adjusted developer waste solution, and a second membrane for membrane separation treatment of the permeate in the first membrane separation step. And a separation step, wherein the permeate in the second membrane separation step is treated in the activated carbon treatment step.   10. The membrane separation process according to claim 8 or 9, wherein the separation membrane in the second membrane separation step is a nanofiltration membrane having a fractional molecular weight of 200 to 900, and the membrane separation treatment is performed at a liquid passing temperature of 40 to 80 ° C. A developing method for recycling a developing waste liquid.   11. The method for regenerating a developing waste liquid according to claim 9, wherein the separation membrane in the first membrane separation step is a microfiltration membrane having a pore diameter of 1 μm or less.   11. The method for regenerating a developing waste liquid according to claim 9 or 10, wherein the separation membrane in the first membrane separation step is an ultrafiltration membrane having a fractional molecular weight of 100,000 or less.   The method for regenerating a developing waste liquid according to any one of claims 8 to 12, wherein a non-regenerating activated carbon tower is used in the activated carbon treatment step.   The absorbance of the permeate in the first membrane separation step is measured according to any one of claims 9 to 13, and the cleaning time of the separation membrane in the second membrane separation step is determined based on the measured absorbance. A method for regenerating a developing waste solution.

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