JPH1110134A - Waste liquid treating apparatus and waste liquid treating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reuse concentrated developer waste liquid as a neutralization agent of acid exhaust gas while an extreme reduction of a volume of the developer waste liquid and its easy operation control are achieved by a method wherein a multiplying factor in concentration of alkaline waste liquid is raised as it is without regulating pH concerning a waste liquid treatment. SOLUTION: (1) While developer waste liquid is supplied under a reduced pressure state (S3), the developer waste liquid is concentrated by heating (S4). (2) The concentrated waste liquid after heating is reserved (S5). (3) The concentration of a specific material contained in the concentrated development waste liquid is measured (S6). (4) When the concentration is lower than a specific value, (1), (2) and (3) are repeated for the stored development waste liquid, and when the concentration of the specific material becomes the specific value or higher, the developer waste liquid is recovered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste liquid processing apparatus and a waste liquid processing method, and more particularly, to a waste liquid processing apparatus and a waste liquid processing method capable of concentrating development waste liquid and reusing the concentrated waste liquid.

[0002]

2. Description of the Related Art In recent years, there has been a demand for reduction of environmentally harmful substances discharged from factories. This waste developing solution is alkaline, exhibits a COD (Chemical Oxygen Demand) value, and TMAH (tetraammonium hydroxide), which is a main component, exhibits biotoxicity, and is incinerated as industrial waste. However, with the recent increase in the diameter of wafers, the amount of use has been steadily increasing, and the amount of development waste liquid has also increased. As measures to be taken in the future, it is necessary to reduce the generated amount itself and efficiently process the generated developing waste liquid.

Conventional processing methods for developing waste liquid include decomposition of the developing waste liquid by a bioactive sludge method and reduction of the volume of the developing waste liquid by a concentration treatment method using an RO membrane. The bioactive sludge method is a method of decomposing a developing waste liquid using microorganisms,
To mitigate the biotoxicity of H, the TMAH concentration in the wastewater
It is necessary to control to about 2000ppm (0.2%). FIG.
Is an experimental example showing this, and is an example showing the water quality of wastewater after being treated by the biologically activated sludge treatment method. In FIG. 4, TOC is an abbreviation for Total Organic Carbon. The TOC-SS load in FIG. 4 refers to the TOC amount (TMAH amount) relative to the amount of microorganisms in the wastewater.

[0004] In the bioactive sludge method, when the TMAH concentration is high, the activity of microorganisms is remarkably reduced, and it takes time to recover the treatment capacity. Furthermore, with the decomposition of TMAH,
A denitrification treatment is required for the generated nitrogen. on the other hand,
The RO membrane concentration method is a kind of filtration method in which the water in the developing waste liquid is passed through the RO membrane and concentrated, and the pH of the raw waste liquid to be treated needs to be weakly alkaline, about 8 to 9. Incidentally, the pH of the developing waste liquid to be treated is usually 12 to
Since it is a strong alkali of 13, it is necessary to adjust the pH of the waste developer as a pretreatment.

Further, in the RO membrane concentration method, an increase in the concentration ratio causes a decrease in the amount of permeated water (see FIG. 6) and a deterioration in water quality (see FIG. 5). As shown in FIGS. 5 and 6, in practice,
The concentration of about 10 times (about 3% in TMAH concentration) is the limit. Therefore, water which occupies most of the development waste liquid even after concentration has a bad influence on the subsequent incineration disposal treatment, and the treatment cost becomes extremely expensive.

[0006]

As described above, in the bioactive sludge method, since microorganisms are used, the management and operation of survival are troublesome, and the tank and the like for containing the developing waste liquid are large, so that the installation space is large. Problem. On the other hand, in the RO membrane concentration method, a large amount of an acidic chemical solution is used as a neutralizing agent because the pH of the developing waste solution needs to be adjusted, and the pH control is not easy. Further, the limit of the degree of concentration is low, and it is difficult to greatly reduce the volume of the developing waste liquid.

Further, when the concentrated waste solution is discarded, it cannot be said that the resources are effectively utilized, and it is desirable to reuse the concentrated waste solution as much as possible. The present invention has been made in view of the above-described problems of the conventional example. By increasing the concentration ratio of the waste liquid while maintaining the alkalinity without adjusting the pH, the volume of the development waste liquid can be significantly reduced and the operation can be easily performed. An object of the present invention is to provide a waste liquid treatment apparatus and a waste liquid treatment method capable of achieving control and reusing a concentrated development waste liquid as a neutralizing agent for acidic exhaust vapor.

[0008]

The first object of the present invention is to provide a developing waste liquid storage tank for storing a developing waste liquid, an inlet for the developing waste liquid, a means for heating the introduced developing waste liquid, A pressure-reducing condensable storage having an exhaust port for vapor evaporating from the developer waste by heating, a reservoir for storing the concentrated developer waste after heating, and a means for measuring the temperature of the developer waste in the reservoir; A tank, a concentrated waste liquid collecting tank for collecting the concentrated developing waste liquid, a first pipe for sending the developing waste liquid in the developing waste liquid storing tank from the developing waste liquid storing tank to an inlet of the concentrated storing liquid tank, A second pipe for recirculating the developing waste liquid in the section to the inlet, and a third pipe for sending the developing waste liquid in the storage section of the concentration storage tank to the concentrated waste liquid recovery tank.
And when the temperature of the developing waste liquid in the storage section is lower than a set temperature under a predetermined pressure, the developing waste liquid in the storage section flows out to the second pipe and is guided to the inlet, and the storage section is When the temperature of the developing waste liquid is equal to or higher than the set temperature under the predetermined pressure, the developing waste liquid in the reservoir is discharged to the third pipe and guided to the concentrated waste liquid collecting tank. A second aspect of the present invention is a waste liquid treatment apparatus characterized in that the means for compressing steam flowing out of an exhaust port of the concentration storage tank and heating the steam heated by compression by the compression means. And a fourth pipe for guiding the heating means to heat the heating means.
Solved by the waste liquid treatment apparatus according to the invention of the third aspect, the third aspect of the invention is to cool the steam that has passed through the heating means,
Means for liquefaction, means for measuring the electric conductivity of the liquid generated by the liquefaction, a waste tank for the liquid, and the electric conductivity guides the liquid toward the waste tank depending on the magnitude relative to a predetermined value, Alternatively, there is provided a waste liquid processing apparatus according to the first or second invention, further comprising second control means for guiding the liquid toward the development waste liquid storage tank, and is a fourth invention. Means for discharging the developing waste liquid provided in the concentration storage tank, and a part of the development waste liquid flowing through the first pipe when bubbles are generated in the development waste liquid in the concentration storage tank. A fifth control invention is solved by the waste liquid treatment apparatus according to any one of the first to third inventions, further comprising: a third control unit that branches off from the pipe and flows to the discharge unit. (1) Under reduced pressure,
Heating while supplying the developing waste liquid to concentrate the developing waste liquid,
(2) storing the concentrated developing waste liquid after the heating,
(3) measuring the concentration of the specific substance contained in the stored developing waste liquid, and (4) when the concentration is lower than a predetermined value, the above-mentioned (1) and (2) for the stored developing waste liquid.
And (3) are repeated, and when the concentration of the specific substance is equal to or higher than the predetermined value, the developing waste liquid is recovered. Measurement of the concentration of specific substances contained
The method according to the seventh aspect, wherein the temperature of the development waste liquid is measured, and the temperature is raised to correspond to the increase in the molar boiling point. The heating of the waste liquid is performed by compressing the vapor generated by the evaporation to increase the temperature of the vapor, and applying the energy of the heated vapor to the developing waste liquid. The invention is solved by a waste liquid treatment method according to the invention.

In the present invention, the concentration of the developing waste liquid and the measurement of the concentration of the specific substance in the concentrated developing waste liquid are repeated until the concentration of the specific substance in the concentrated developing waste liquid reaches a predetermined value. The concentration of the specific substance contained in the development waste liquid can be easily measured by, for example, measuring the temperature of the development waste liquid and making the temperature correspond to the rise in the molar boiling point.

In this case, the circulating system of the stored developing waste liquid for concentrating the developing waste liquid until the concentration of the specific substance reaches a predetermined value has the configuration of the concentration processing apparatus of the present invention. That is,
When the temperature of the developing waste liquid stored in the storage section of the concentration storage tank is lower than the set temperature, the development waste liquid in the storage section flows out to the second pipe and is again led to the introduction port of the development waste liquid in the concentration storage tank. When the temperature of the developing waste liquid is equal to or higher than the set temperature, first control means is provided for causing the developing waste liquid in the storage section to flow out to the third pipe and to guide the developing waste liquid to the concentrated waste liquid collecting tank.

According to the present invention, the concentration of a specific substance, for example, TMAH in water can be reduced by circulating and gradually concentrating the developing waste liquid. Therefore, without causing problems such as environmental pollution by specific substances,
Drainage can be performed easily. The concentration of the specific substance (TMAH) is measured for each circulation. By the way, if TMAH (specific substance) contained in the developing waste liquid is excessively concentrated, it will solidify at room temperature and cannot be contained in the recovery tank kept at room temperature, which is a practical problem. According to this, the problem can be solved by setting the critical concentration of TMAH as a predetermined value.

Further, the evaporation temperature can be lowered by evaporating the water in the developing waste liquid under reduced pressure. For this reason, energy cost can be reduced. Further, it is said that TMAH is thermally decomposed into trimethylamine at about 130 ° C.
By lowering the temperature below ℃, thermal decomposition can be suppressed,
For this reason, it is also possible to reuse acidic exhaust gas as a neutralizing agent.

Further, the developing waste liquid is heated by compressing the vapor generated by the evaporation to increase the temperature of the vapor and applying the energy of the heated vapor to the developing waste liquid.
In this case, the device configuration is as follows. That is, a heating means which is heated by the heat energy of the heated steam is used as the heating means, and the steam compression means and the steam which has been heated by being compressed by the compression means are introduced into the exhaust port of the concentration storage tank to the heating means. Connect to the fourth pipe.

In energy saving and the like, although energy saving and the like have been partially achieved, it is important to prevent energy from being consumed elsewhere in order to achieve the energy saving and the like. According to the present invention, since the thermal energy of the vapor evaporated from the development waste liquid is used to heat the development waste liquid itself, the energy can be effectively used, and energy saving can be achieved as a whole. it can.

Further, in the present invention, there is provided a means for measuring the electric conductivity of a liquid generated by liquefaction of steam coming out of an exhaust port of a concentration storage tank or steam passing through a heating means; Second control means for guiding the liquid toward the waste tank or the developing waste liquid storage tank according to the magnitude of the predetermined value. From the magnitude of the electric conductivity, it is possible to know the approximate level of the concentration of the specific substance (TMAH) in the wastewater. That is, for example, when the electric conductivity is high, the concentration of the specific substance is high, and when the electric conductivity is low, it is known that the concentration is low. Only clean wastewater with low concentration can be discarded. The wastewater having a high concentration of the specific substance may be returned to the developing waste liquid storage tank again.

Further, there is provided a discharge means for developing waste liquid provided in the concentration storage tank, and a third control means for branching from the first pipe and flowing a part of the developing waste liquid flowing through the first pipe to the discharging means. Having. With this, when bubbles are generated on the surface of the developing waste liquid in the storage part because the developing waste liquid contains a surfactant, the developing waste liquid is discharged into the concentration storage tank by using a part of the developing waste liquid to be appropriately treated. Can be defoamed.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram illustrating a configuration of a developing waste liquid concentration processing apparatus (waste liquid processing apparatus) according to an embodiment of the present invention. As a developing waste liquid, a developing waste liquid (main component: tetraammonium hydroxide; hereinafter, referred to as TMAH) generated by patterning using a resist film as a mask in a photolithography step and then dissolving the resist film is used. The concentrated developer waste is reused as a neutralizing agent for acidic exhaust gas and the like.

[0018] concentration treatment apparatus development waste, as shown in FIG. 1, a waste developer reservoir T ₁ for storing a waste developer generated in the photolithography process, a development waste was concentrated under reduced pressure concentrates reservoir to reservoir has a T _2, a concentrated waste liquid collecting tank T ₃ for collecting the concentrated development waste. To use a reduced pressure concentrates reservoir T ₂ are, when heating the waste developer evaporate water in the development waste, as TMAH which is to be thermally decomposed at approximately 130 ° C. does not cause thermal decomposition, This is for reducing the evaporation temperature to 80 ° C. or less. Therefore, the exhaust system A ₅ to reduce the pressure in the concentrate reservoir T ₂ the pipe P
And it is connected to the concentrate reservoir T ₂ through _16.

The concentrated storage tank T ₂ has an inlet I for developing waste liquid.
₁ is formed, a developing waste liquid is introduced from the inlet I ₁ in concentrated reservoir T _2. Immediately below inlet I ₁ of the waste developer is provided heating means A _1, waste developer introduced into the concentrate reservoir T ₂ are heated by sequentially heating means A _1. The heating means A ₁ is a heat exchanger having a metal heat transfer tube,
This is to increase the surface temperature of the heat transfer tube by flowing steam into the heat transfer tube. Since steam evaporated from the developing waste liquid is used as high-temperature steam passing through the heat exchanger, high-temperature steam cannot be used in the initial stage of operation of the concentration treatment device. In that case, steam is supplied from the outside of the concentration treatment device.

By heating using the heating means A ₁ , water containing TMAH and the like evaporates from the developing waste liquid and is discharged to the outside through the exhaust port O ₁ . The outlet O ₁ is connected to the compressor A ₃ vapor, compressing the high-temperature steam generated by evaporation, to increase its temperature 2 to 3 ° C.. It sends the high-temperature steam into the heating means A _1, is used as steam for heating. further,
The steam having passed through the heat exchanger A ₁ is cooled, and a condenser A ₄ to liquefy, and the electric conductivity meter M ₂ to measure the electrical conductivity of the produced by liquefaction liquid. By measuring the electric conductivity of the liquid, the approximate concentration of TMAH (specific substance) in the liquid can be determined. That is, when the electric conductivity is high, the concentration of TMAH is high, and when the electric conductivity is low, the concentration is low. Therefore, by setting a predetermined value to a concentration that does not cause environmental pollution, only a clean liquid can be drained. Although used in which liquefied electrical conductivity has passed through the heat exchanger A ₁ as the liquid for measuring the steam, directly liquefying the vapor emerging through the outlet of the concentrate reservoir T ₂ optionally You may use what was done.

Meanwhile, waste developer containing water in the concentration decreases by heating reservoir A which is provided in the lower portion of the concentrate storage tank T ₂
Stored in ₈ . The reservoir A _8, the means M ₁ for measuring the temperature of the reservoir has been developed waste is provided. The temperature of the developing waste solution concentrated by the means M ₁ for measuring the temperature is measured, and ΔT _b = RT _b ² Mm / ΔH (= K _bm ) where M: mol of solvent mass T _b: the boiling point of the solvent [Delta] H: molar heat of vaporization m solvents: molal concentration of solvent K _b: by associating the molar ebullioscopic constant temperature and mole ebullioscopic, indirect concentration of TMAH in the development waste Can be measured. Therefore, the concentration measurement can be easily performed.

FIG. 3 shows the results of an investigation on the relationship between the concentration of TMAH (wt%) and the evaporation temperature (° C.) by experiments based on the principle of increasing the molar boiling point. The pressure at this time is about 60
It is around 0 mmHg. Further, a shower A ₆ capable of discharging the developing waste liquid itself circulating through the concentration processing device and a shower A capable of introducing an antifoaming agent are provided in the concentration storage tank T ₂ .
₇ and are installed. Defoamer is supplied from the tank T _4. The reason for installing these showers A ₆ and A ₇ is that
It is as follows. That is, since the developing waste liquid may contain a surfactant, when the developing waste liquid is heated, bubbles are generated. These air bubbles are successively stacked on the surface of the developing waste liquid stored in the concentration storage tank T ₂ , and are concentrated.
Will be filled within ₂ . This is because in this state, it is necessary to defoam in order to hinder concentration.

Next, the connection relationship between the above-described tanks and the like and the control means for controlling the flow of the waste developer flowing through the pipe connecting them will be described. A pipe P ₁ -P ₂ -P ₃ -P ₄ -P ₅ (first pipe R) is provided between the development waste liquid storage tank T ₁ and the development waste liquid introduction port I ₁ of the concentration storage tank T _2.
1 ) connected by Storage part A of concentrated storage tank T _2
8 and between the inlet I ₁ is the pipe P ₆ -P ₂ -P ₃ -P ₄
It is connected by -P ₅ (second pipe R _2).

Concentration storage tank T_TwoReservoir A of₈And concentrated waste liquid times
Tank T_ThreeIs the pipe P₆−P_Two−P _Three−P₇(Third distribution
Tube R_Three). And storage part A₈of
When the temperature of the developing waste liquid is lower than a predetermined temperature, the storage unit A
₈Of the developing waste from the second pipe R_TwoTo the waste developer
Inlet I₁To the reservoir A₈The temperature of the developing waste liquid
When the temperature is higher than or equal to₈Development waste liquid into the third pipe
R_ThreeTo the concentrated waste liquid recovery tank T_ThreeFirst control that leads to
Means C₀Having.

First control means C₀Means switching means C₁,
C_TwoAnd controller C_ThreeAnd pump A _TwoConsists of Switching
Means C₁Is piping P₁And P_TwoAnd P₆Provided at the branch of
P₁And P_Two, Or P_TwoAnd P₆Conduct between
Let it. Switching means C_TwoIs piping P_ThreeAnd P _FourAnd P₇Branch of
Is installed in the pipe P_ThreeAnd P_FourBetween the current
Image waste liquid is introduced into development waste liquid inlet I₁Or pipe P
_ThreeAnd P₇Between the developing waste liquid and the concentrated waste liquid collecting tank T.
_ThreeSend to Controller C_ThreeSets the temperature of the waste developer
Means M for measuring₁Receives the temperature information of the developing waste liquid from
Switching means C based on temperature₁, C_TwoSwitch appropriately
You.

[0026] Pump A ₂ is installed between the pipe P ₂ -P _3, the pipe P _2, P ₃ the development waste liquid concentrated liquid waste collection tank in T
₃ and flows towards the inlet I ₁ of the development waste concentrate reservoir T _2. Also, the shower A ₆ and the storage section A ₈ of the concentration storage tank T ₂ are used.
It is connected through a pipe _{P 6 -P 2 -P 3 -P 4} -P 14 and. Third control means C ₄ is provided in the branch portion of the pipe P ₄ and P ₅ and P _14. Usually brought into conduction only during the pipe P ₄ and P _5, and keep disconnects the pipe P ₄ and P _14. To further conduct via the pipe P ₄ and P ₁₄ when the bubble is generated in the concentrate reservoir T _2, and sends a portion of the waste developer through the P ₅ from the pipe P ₄ to the shower A _6.

A pipe P ₈ is provided between the compressor A ₃ and the heat exchanger A _1.
Are connected by via a pipe P ₉ in the heat exchanger A _1,
Furthermore during the heat exchangers A ₁ and capacitor A ₄ are connected by a pipe P _10, the capacitor A ₄ and the electrical conductivity measuring device M ₂
Between it is connected by a pipe P _11. In addition, piping P ₁₁
Branches to a pipe P ₁₂ and P _13, the other end of the pipe P ₁₃ leads the developer storage tank T _1, the other end of the pipe P ₁₂ in disposal tank (not shown) discards the moisture extracted from the development waste Connect.

[0028] The branch portion of the pipe P ₁₁ and P ₁₂ and P ₁₃ are the second control means C ₅ are provided. Second control means C
_5, the developing electric conductivity of the water evaporated from the waste developer is when higher than the predetermined value is cut off between the pipe P ₁₁ and P _12, the water by conduction between the pipe P ₁₁ and P ₁₃ Liquid storage tank T
Send to ₁ When the electrical conductivity is lower than a predetermined value, and disconnects the pipe P ₁₁ and P _13, the pipe P ₁₁ and P ₁₂
And water extracted from the waste developer is sent to the waste tank. When electric conductivity is high, TMAH
Is contained at a concentration equal to or higher than a predetermined concentration and cannot be discarded, and can only be discarded when the electric conductivity becomes lower than a predetermined value.

[0029] In the above-described concentration treatment apparatus, floor area approximately 16m ² becomes required for installing the devices, as compared to the concentration method according to the conventional example of the RO membranes was required about 110m ^2, becomes 1/7 or less . In addition, it is about 1/10 as compared with the conventional biologically activated sludge method that required about 150 m ² . Therefore, space saving can be achieved as compared with the conventional example.

Next, a method for concentrating a developing waste liquid using the above-mentioned concentrating apparatus will be described. FIG. 2 is a flowchart showing the flow of the concentration processing method. First, waste developer from the developing device to come discarded (S1), is accumulated in the waste developer storage tank T ₁ (S2). The concentration of TMAH in the waste developer is about 0.289 wt%. And evacuating the concentrate reservoir T ₂ to reduce the pressure in the tank. At this time, 0.289 wt% of TMAH
So that the evaporation temperature of the development waste liquid, which is the concentration, is 70 ° C.
And sets the degree of vacuum in the vessel back and forth 600 mm Hg, and send the temperature 70 ° C. of the gas from the outside to the heating means A _1, previously maintained at a temperature 70 ° C. The surface of the heating means A _1.
Note optionally by a heater, the heating means A ₁ may be preheated to 70 ° C..

[0031] When the accumulated proper amount of development waste to waste developer reservoir T _1, piping from the development waste reservoir T ₁ P ₁ -P ₂
-P ₃ -P ₄ -P ₅ (first pipe R ₁₎ flowing a developing waste liquid inlet I ₁ of the development waste concentrate reservoir T ₂ through. Then, to release from the inlet I ₁ the development waste in concentrated reservoir T ₂ (S3). Development waste is heated in contact with the heating means A _1, moisture in the development waste evaporates (S4). The vapor generated by the evaporation enters the compressor A ₃ from the outlet O ₁ ,
Compressed. Thereby, the temperature of the steam increases by 2 to 3 ° C. Heated steam is sent to the heating means A _1. In this case, the heating means A ₁ is high-temperature gas from the outside is introduced, it switched as steam heated and evaporated from the developing waste liquid is introduced. Heated steam heats the heating means A ₁ through heating means A _1, raising the temperature of the heating means A _1.

On the other hand, the developing waste liquid remaining in the concentration storage tank T ₂ without evaporating falls from the heating means A ₁ and drops in the concentration storage tank T _2.
Collects in the bottom of the reservoir A _8. Since development waste reservoir portion A ₈ moisture is considerably removed, the concentration of TMAH is high. In this way, going pooled and concentrated to reservoir A ₈ development waste. The temperature of the developing waste liquid is constantly measured (S6).

At this time, as shown in FIG. 3, the evaporation temperature increases as the concentration progresses. However, if the end point temperature does not reach 80 ° C. or less, the concentration control tank T ₂ is controlled by the first control means C _0. pipe from the reservoir _{a 8 P 6 -P 2 -P 3} -
P ₄ -P ₅ sends a development waste again inlet I ₁ of concentrate reservoir T ₂ through (second pipe R ₂₎ (S3). And
Further, the developing waste liquid is evaporated (S4) and stored (S5) by the method described above. In this manner, the developing waste liquid is repeatedly evaporated, stored, and concentrated until the evaporating temperature of the developing waste liquid reaches the set temperature.

The evaporating temperature of the developing waste liquid has reached the set temperature.
The first control means C₀By concentration tank T_TwoStorage department
A₈From piping P₆−P_Two−P_Three−P₇(Third piping
R_Two) Through the concentrated waste liquid recovery tank T_ThreeThe developing waste liquid.
By the way, in the concentration processing step S8, the concentration storage tank T_Two
Evaporates in the compressor A _ThreeHeating means A₁Through
The escaped steam is condenser A_FourLiquefied by cooling
(S9). After that, the electric conduction of the liquid generated by liquefaction
The conductivity is measured (S10), and the electric conductivity is larger than a predetermined value.
When the amount of TMAH contained in the liquid is high,
Then, the liquid is transferred to a developing waste liquid storage tank T.₁(S2). Ma
Also, when the electric conductivity becomes lower than the specified value, neutralization
Processing is performed (S11), and discarded (S12).

Further, during concentration, when bubbles on the surface of the developing waste liquid reservoir A ₈ went stacked occur, to further conduct a pipe P ₄ -P ₁₄ by the control unit C _4, the development waste one flow of parts to the shower a _6. Thereby, the storage unit A
The development waste liquid is released to the surface of the development waste liquid of No. ₈ and defoaming is performed. In the case where too excessive foaming occurs, leads from the tank T ₄ antifoam in concentrate reservoir T _2, is sprayed on the surface of the developing waste liquid reservoir A ₈ from the shower A _7. Thus, it is possible to perform defoaming of the surface of the waste developer in the reservoir A _8.

Table 1 shows the quality of the condensed water of the concentrated development waste liquid as described above.

[0037]

[Table 1]

As shown in Table 1, the water quality of the condensed water is weakly alkaline, but the pH value falls within the range (pH 5.8 to pH 8.6) specified by the Water Pollution Control Law. It can be said that it is water quality. In addition, it can be said that other parameters such as the COD value indicating the quality of water quality and the total nitrogen content are within a range without any problem. As described above, in the embodiment of the present invention, until the concentration of TMAH in the concentrated developing waste liquid reaches a predetermined value, evaporation of water in the developing waste liquid and measurement of the concentration of TMAH in the developing waste liquid after evaporation are performed. And has been repeated.

By circulating and gradually concentrating the developing waste liquid, the TMAH concentration in the water can be reduced. Therefore, drainage can be easily performed without causing problems such as environmental pollution due to TMAH. Also, since the concentration of TMAH is measured for each circulation, the critical concentration of TMAH contained in the developing waste liquid is set as a predetermined value to prevent the concentrated developing waste liquid from solidifying in the recovery tank. can do.

Further, the evaporation temperature can be reduced by evaporating the water in the developing waste liquid under reduced pressure. For this reason, energy cost can be reduced. In addition, by lowering the evaporation temperature, thermal decomposition of TMAH can be suppressed, and therefore, it is possible to reuse acidic exhaust gas as a neutralizing agent. In addition, the vapor generated by the evaporation is compressed to increase the temperature of the vapor, and the energy of the heated vapor is applied to the waste developer to heat the waste developer. In energy saving, etc., energy saving was achieved in part, but it is important not to consume energy in other places to achieve the energy saving, etc. Since the thermal energy of the evaporated vapor is used to heat the development waste liquid itself, the energy can be effectively used, and energy saving can be achieved as a whole.

[0041]

As described above, in the present invention, the evaporation of the water in the development waste liquid and the evaporation of the water in the development waste liquid until the concentration of the specific substance in the concentrated development waste liquid reaches a predetermined value. The measurement of the concentration of the specific substance is repeated.
By circulating and gradually concentrating the developing waste liquid, the concentration of the specific substance in the water can be reduced. Therefore, drainage can be easily performed without causing a problem such as environmental pollution due to the specific substance.

The concentration of a specific substance in the developing waste liquid is measured for each circulation. In this case, by setting the critical concentration of the specific substance as a predetermined value, it is possible to prevent adverse effects due to concentration such as solidification of the development waste liquid. Further, the evaporation temperature can be reduced by evaporating the water in the developing waste liquid under reduced pressure. For this reason, energy cost can be reduced. In addition, thermal decomposition of a specific substance (for example, TMAH) in the development waste liquid can be suppressed, and therefore, it is possible to reuse acidic exhaust gas as a neutralizing agent.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall configuration of a developing waste liquid concentration processing apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a method for concentrating a developing waste liquid according to an embodiment of the present invention.

FIG. 3 is a characteristic diagram showing a rise in a boiling point with respect to a TMAH concentration of a developing waste liquid according to the embodiment of the present invention.

FIG. 4 is a characteristic diagram showing a relationship between a TMAH concentration in wastewater after treatment by a biologically activated sludge method and a total organic carbon amount according to a conventional example.

FIG. 5 is a characteristic diagram showing water quality of wastewater with respect to a concentration ratio by an RO membrane concentration method according to a conventional example.

FIG. 6 is a characteristic diagram showing the amount of permeated water of a developing waste solution with respect to the concentration ratio by the RO membrane concentration method according to the conventional example.

[Explanation of symbols]

A ₁ heat exchanger (heating means), A ₂ pump, A ₃ compressor, A ₄ condenser, A ₅ exhaust device, A ₆ , A 7 shower, A ₈ storage unit, C ₀ first control means, C ₁ , C ₂ switching means, C ₃ controller, C ₄ a third control unit, C ₅ second control means, I ₁ inlet of the developing waste, M1 means for measuring the temperature of the developing waste, M2 electric conductivity meter ( means for measuring the electrical conductivity), P ₀ to P ₁₆ pipe, O ₁ outlet, T ₁ development waste reservoir, T ₂ concentration storage tank, T ₃ concentration waste liquid collecting tank, tank T ₄ defoamer.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Isamu Tatsuno 6-7-5 Moundoshima, Nishiyodogawa-ku, Osaka-shi, Osaka Inside Sasakura Inc. No. Sasakura Co., Ltd. (72) Inventor Keiji Yamada 6-7-5 Motejima, Nishiyodogawa-ku, Osaka-shi, Osaka

Claims (7)

[Claims] A developing waste liquid storage tank for storing the developing waste liquid; an inlet for the developing waste liquid; a unit for heating the introduced developing waste liquid; an exhaust port for vapor evaporated from the developing waste liquid by the heating; A reservoir for storing the concentrated developer waste after heating, a decompressible concentration reservoir having means for measuring the temperature of the developer waste in the reservoir, and a concentrated waste recovery tank for collecting the concentrated developer waste A first pipe for sending a developing waste liquid in the developing waste liquid storage tank from the developing waste liquid storage tank to an introduction port of the concentration storage tank; and a second pipe for returning the developing waste liquid in the storage section to the introduction port.
And a third pipe for sending the developing waste liquid in the storage part of the concentration storage tank to the concentrated waste liquid recovery tank, and when the temperature of the development waste liquid in the storage part is lower than a set temperature under a predetermined pressure, The developing waste liquid in the storage section is caused to flow out to the second pipe and guided to the inlet, and when the temperature of the developing waste liquid in the storing section is equal to or higher than the set temperature under the predetermined pressure, the developing waste liquid in the storing section is discharged. A wastewater treatment apparatus comprising: first control means for flowing out to the third pipe and leading to the concentrated waste liquid recovery tank. 2. A means for compressing steam flowing out from an exhaust port of the concentration storage tank, and a fourth means for guiding the steam compressed and heated by the compression means to the heating means to heat the heating means. The waste liquid treatment apparatus according to claim 1, further comprising a pipe. 3. A means for cooling and liquefying the vapor that has passed through the heating means, a means for measuring the electric conductivity of the liquid generated by the liquefaction, a waste tank for the liquid, 2. A control device according to claim 1, further comprising second control means for guiding the liquid toward the waste tank depending on the magnitude of the predetermined value, or guiding the liquid toward the developing waste liquid storage tank. 3. The waste liquid treatment apparatus according to 2. 4. A discharging means for discharging the developing waste liquid provided in the concentration storage tank, and a part of the developing waste liquid flowing through the first pipe when bubbles are generated in the developing waste liquid in the concentration storage tank. A third branch branched from the first pipe and flowing to the discharging means;
The waste liquid treatment apparatus according to any one of claims 1 to 3, further comprising: a control unit. 5. The method according to claim 1, further comprising: (1) heating the developing waste liquid while supplying the developing waste liquid under reduced pressure to concentrate the developing waste liquid; (2) storing the concentrated developing waste liquid after the heating; and (3) storing the stored developing waste liquid. The concentration of the specific substance contained in the waste liquid is measured. (4) When the concentration is lower than a predetermined value, the above (1), (2) and (3) are repeated for the stored developing waste liquid, and A waste liquid processing method, wherein the developing waste liquid is collected when the concentration of the specific substance is equal to or higher than the predetermined value. 6. The method according to claim 5, wherein the measurement of the concentration of the specific substance contained in the developing waste liquid is performed by measuring a temperature of the developing waste liquid and making the temperature correspond to an increase in the molar boiling point. The waste liquid treatment method described in the above. 7. The heating of the developing waste liquid is performed by compressing the vapor generated by the evaporation to increase the temperature of the vapor, and applying energy of the heated vapor to the developing waste liquid. The waste liquid treatment method according to claim 5 or 6, wherein