TWI706918B - Biological treatment method and biological treatment device - Google Patents

Abstract

The present invention performs efficient biological treatment on organic discharge water containing amines and/or quaternary ammonium salts discharged from the semiconductor and liquid crystal manufacturing process to obtain high-quality treated water with high removal of organic nitrogen . In the method of introducing organic discharged water into a biological treatment tank for biological treatment, the measured value of the concentration of amine and the fourth grade ammonium ion in the liquid in the biological treatment tank or the effluent of the biological treatment tank is compared with the concentration of ammonium ion and nitrate ion. At least one measured value of the concentration and the concentration of nitrite ions is used as an indicator to adjust the biological treatment method of the biological treatment conditions.

Description

Biological treatment method and biological treatment device

The present invention is a biological treatment method and a biological treatment device that can be effectively used as a cost-saving automatic control or operation management method in an organic discharge water recovery treatment system related to the semiconductor and liquid crystal manufacturing process.

Ultra-pure water discharged from the semiconductor and liquid crystal manufacturing process. Recycling organic discharged water, mainly composed of various amines such as ethanolamine, and organic containing alkali components such as N-methylformamide and tetramethylammonium hydroxide (TMAH) Department of discharge water. The biological treatment method of organic discharge water can use activated sludge method (AS), membrane separation activated sludge method (MBR), fluidized bed biological treatment method (MBBR), activated sludge method with added support (IFAS), etc. .

In the biological treatment tank, amines and other organic substances are oxidized and decomposed, and the ammonia generated by the oxidative decomposition is nitrified by nitric acid. The pH in the biological treatment tank decreases due to the production of nitric acid. Therefore, alkali must be added to the biological treatment tank to maintain a neutral pH. The effluent from the biological treatment tank can be separated into solid-liquid by a sedimentation tank, etc., and then coagulated by an inorganic flocculant, and then subjected to a reverse osmosis (RO) membrane separation treatment to recover filtered water for reuse.

The above-mentioned discharge water treatment has the following problems.

(1) In the biological treatment tank, in order to compensate for the decrease in alkalinity accompanying the nitrification reaction and maintain good biological treatment efficiency, an alkali agent whose purpose is to maintain pH around 7, for example, must be added. Adding an alkali agent will cost the cost of the alkali agent itself. Due to the addition of the alkali agent, the ion concentration in the recovered water is increased, and the ion load of the RO membrane separation treatment and the salt load of the RO membrane concentrated water are increased. Disposal of RO membrane concentrated water will increase the processing cost.

(2) When the alkali agent is added in excess, the alkalinity of the biologically treated water will increase. In order to achieve the most suitable pH range of 5 to 6 during the subsequent coagulation treatment, when the alkalinity of the biologically treated water is high, an acid must be added to lower the pH, or an acidic inorganic coagulant must be added excessively. Adding an acid agent not only costs the acid agent itself, but also increases the ion concentration in the recovered water. Increasing the ion load of RO membrane separation treatment and the salt load of RO membrane concentrated water will result in increased treatment costs when RO membrane concentrated water is discarded. Excessive addition of inorganic flocculants will increase the amount of sludge, resulting in an increase in the disposal cost of the excess sludge.

In order to solve the above problems, the following countermeasures (I) and (II) are proposed.

(I) By introducing a nitrogen treatment (denitrification) function into the biological treatment tank, the decrease in alkalinity accompanying the nitrification reaction is suppressed, and the amount of alkali agent added is suppressed as much as possible. In order to perform operation management to achieve this purpose, the concentration of ammonium ions, nitrate ions, or nitrite ions (hereinafter, this plasma may be collectively referred to as "()nitrite ions") in the liquid in the biological treatment tank is continuously monitored. Make appropriate adjustments to denitrification treatment conditions.

(II) In order to reduce the alkalinity of the biologically treated water, the target value of pH control during biological treatment is set to the lowest possible limit.

Patent Document 1 proposes a method for monitoring the concentration of nitrite ions during nitrification and denitrification. Patent Document 2 proposes a method for adjusting the processing conditions based on the concentration of nitrite ions. Patent documents 3 and 4 propose methods for adjusting processing conditions based on ammonium ion concentration.

Patent Document 1: Japanese Patent No. 696517 Specification

Patent Document 2: Japanese Patent No. 5742195 Specification

Patent Document 3: Japanese Patent No. 5727291 Specification

Patent Document 4: Japanese Patent No. 4865211 Specification

According to the countermeasures (I) and (II) above, it is difficult to manage and adjust the appropriate nitrogen treatment as described below.

The organic discharge water from the semiconductor and liquid crystal manufacturing process contains organic nitrogen mainly composed of amines and quaternary ammonium salts. Therefore, when the above (I) only monitors the concentration of ammonium ion and (nitrite) nitrate ion, the ammonium ion concentration is also low when nitrification is not carried out due to poor decomposition of organic nitrogen, and it will be irrelevant whether the nitrification reaction is fully proceeded. It was misjudged as a case of ongoing nitrification.

According to the countermeasure of (II) above, it is difficult to respond on-site as described below.

Although the alkalinity of the treated water can be reduced by lowering the pH control target value, the premise of nitrogen treatment is that the nitrification reaction can proceed well at a higher pH (for example, 7.0 or higher), so it is difficult to determine how far to lower the pH. Cause to hinder the nitrification reaction.

The present invention is to provide efficient biological treatment of organic discharge water containing amines and quaternary ammonium salts discharged from the semiconductor and liquid crystal manufacturing process to obtain high-quality treated water with a high degree of removal of organic nitrogen The biological treatment method and the biological treatment device are for the purpose.

The inventors discovered that, in addition to the previous operation management based on the concentration of ammonium ions and (nitrous) nitrate ions, they further analyzed the amine and quaternary ammonium ion concentrations in the biological treatment process, and confirmed by online or manual analysis The accumulation state of amine and quaternary ammonium ions in the reaction system can be automatically controlled or operated appropriately.

The gist of the present invention is as follows.

[1] A biological treatment method, which is a method of introducing organic discharged water into a biological treatment tank for biological treatment, and measuring the concentration of amine and fourth-grade ammonium ion in the biological treatment tank or the effluent from the biological treatment tank Value, and the measured value of at least one of ammonium ion concentration, nitrate ion concentration, and nitrite ion concentration as an index to adjust the biological treatment conditions.

[2] In [1], the aforementioned biological treatment tank is a nitrification tank or a nitrification and denitrification tank. In the case of a nitrification tank, adjust the nitrification conditions and/or pH control target value as the biological treatment conditions, and adjust the nitrification and denitrification tank As Any one of nitrification conditions, denitrification conditions, and pH control target values of biological treatment conditions.

[3] The biological treatment method of [1] or [2], wherein the aforementioned biological treatment system uses any of the activated sludge method, membrane separation activated sludge method, fluidized bed biological treatment method, activated sludge method with added support, etc. One for processing.

[4] The biological treatment method of any one of [1] to [3], wherein the aforementioned organic discharged water is discharged from the semiconductor and liquid crystal manufacturing process containing amines and/or quaternary ammonium salts.

[5] The biological treatment method of any one of [2] to [4], wherein the adjustment of the nitrification conditions is to increase or decrease the dissolved oxygen concentration of the liquid in the nitrification tank, increase or decrease the pH, or increase or decrease the nitrification time.

[6] The biological treatment method of any one of [2] to [5], wherein the adjustment of the denitrification conditions is to increase or decrease the dissolved oxygen concentration of the liquid in the nitrification tank, increase or decrease the pH, or increase or decrease the nitrification time .

[7] The biological treatment method of any one of [2] to [6], wherein the sum of the measured value of the aforementioned amine and quaternary ammonium ion concentration and the measured value of the ammonium ion concentration is less than the preset standard value, The aforementioned pH control target value will be lowered.

[8] A biological treatment device, which is a biological treatment device for organic discharge water, has a biological treatment tank into which the organic discharge water is introduced, and measuring the amine in the biological treatment tank or the effluent of the biological treatment tank And the first measuring method of the 4-level ammonium ion concentration, and measuring the ammonium ion concentration and nitrate ion of the biological treatment tank or the effluent of the biological treatment tank A second measuring means for at least one of the concentration and the nitrite ion concentration, and a control means for adjusting the biological treatment conditions of the biological treatment tank based on the measured value of the first measuring means and the measured value of the second measuring means.

[9] The biological treatment device of [8], wherein the biological treatment tank is a nitrification tank or a nitrification ‧ denitrification tank, and the aforementioned control means is used in the nitrification tank to adjust the nitrification conditions and/or pH control target values as the biological treatment conditions In the nitrification and denitrification tank, it is a means to adjust any of the nitrification conditions, denitrification conditions, and pH control target values as biological treatment conditions.

[10] The biological treatment device of [8] or [9], wherein the aforementioned biological treatment is any one of activated sludge treatment, membrane separation activated sludge treatment, fluidized bed biological treatment, activated sludge treatment with added support, etc. .

[11] The biological treatment device of any one of [8] to [10], wherein the organic discharge water system comes from discharge water containing amines and/or grade 4 ammonium salts discharged from the semiconductor and liquid crystal manufacturing process.

[12] The biological treatment device of any one of [9] to [11], wherein the aforementioned control means is used to adjust the aforementioned nitrification conditions by increasing or decreasing the dissolved oxygen concentration of the liquid in the aforementioned nitrification tank, increasing or decreasing the pH, or increasing Means to reduce nitrification time.

[13] The biological treatment device of any one of [9] to [12], wherein the aforementioned control means is used to adjust the aforementioned denitrification conditions by increasing or decreasing the dissolved oxygen concentration of the liquid in the nitrification tank, increasing or decreasing the pH, or Means to increase or decrease nitrification time.

[14] The biological treatment device of any one of [9] to [13], wherein the aforementioned control means is based on the amine and quaternary ammonium ion concentrations measured by the aforementioned first measuring means and the aforementioned second measuring means. When the sum of the measured values of the measured ammonium ion concentration is less than the preset standard value, it is a means to lower the aforementioned pH control target value.

According to the present invention, based on the following effects, organic nitrogen can be efficiently treated.

(1) By monitoring the decomposition status of amines and quaternary ammonium salts used in the semiconductor and liquid crystal manufacturing process and reflecting it to the control management, the amines and quaternary ammonium salts that are the prerequisite for nitrogen treatment can be maintained Decomposition also maximizes nitrogen treatment efficiency. As a result, the amount of alkali agent added during biological treatment can be minimized, and running costs can be reduced.

(2) By maintaining the target nitrogen treatment efficiency and lowering the pH control target value, the alkalinity of the treated water can be reduced. The amount of acid added in the subsequent agglutination process and the amount of inorganic flocculant added can also be minimized. Reduce regular costs.

Hereinafter, the implementation of the biological treatment method and biological treatment device of the present invention will be described in detail.

"Amine" refers to monomethylamine, dimethylamine, trimethylamine, and monoethanolamine, which is represented by NR ¹ R ² R ³ . The "quaternary ammonium salt" is represented by N ⁺ R ¹ R ² R ³ ‧X ^- such as tetraalkylammonium hydroxide such as tetramethylammonium hydroxide.

Amine and quaternary ammonium ions cannot be determined by the measurement of ammonium ion concentration.

The organic discharged water to be treated in the present invention preferably comes from the discharged water containing amines and/or quaternary ammonium salts discharged from the semiconductor and liquid crystal manufacturing process. For example, the ultrapure water recovery system in the semiconductor and liquid crystal manufacturing process can be mentioned. The organic system discharges water. The water quality of the organic discharged water of the ultrapure water recovery system depends on whether other discharged water is mixed or the mixing amount of other discharged water. Generally, it has the following water quality.

<Quality of organic discharged water from ultrapure water recovery system>

pH: 8~11

TOC: 10~200mg/L

TOC ingredients: Monomethylamine (MMA), dimethylamine (DMA), trimethylamine (TMA), monoethanolamine (MEA) and other amines, N-methylformamide and other amines, hydroxide Quaternary ammonium salts such as tetraalkylammonium hydroxide such as tetramethylammonium (TMAH).

The ratio of amines and quaternary ammonium salts in TOC components: 10~100%

In the present invention, when the organic discharged water is introduced into a biological treatment tank and then subjected to biological treatment, the concentration of amine and quaternary ammonium ions in the liquid in the biological treatment tank or the effluent of the biological treatment tank is measured, and the concentration of ammonium ion and nitrate ion are measured at the same time. At least one of the concentration and the nitrite ion concentration, and the measured values are used as indicators to adjust the biological treatment conditions.

When the treated organic discharge water does not contain the nutrients and metal salts necessary for biological treatment, it is better to add the necessary metal salts and nutrients and then provide it for biological treatment.

The amine concentration, quaternary ammonium ion concentration, ammonium ion concentration, and (nitrite) nitrate ion concentration can be measured using ion column chromatography as in the examples disclosed below. Other LC-MS analysis can also be used for more accurate analysis.

The ammonium ion concentration can generally be determined by the indophenol method. The concentration of nitrite ions can be determined by the naphthylethylenediamine colorimetric method. Nitrate ion concentration can also be measured by general analysis methods such as the naphthylethylenediamine colorimetric method (cadmium column method) combined with cadmium column reduction to nitrite.

Since in the present invention, the concentration of amine and level 4 ammonium ions must be measured, the ion column chromatography that can individually analyze the plasma is the simplest analytical method.

The structure of the biological treatment tank is not particularly limited, and the present invention is applicable to general nitrification (denitrification) processes. The invention is particularly suitable for use in the case of biological nitrification and, preferably, simultaneous denitrification. The biological treatment tank can also be used for the nitration reaction of nitrogen in an aerobic reaction tank. The structure of the biological treatment tank can also be a nitrification tank and a denitrification tank in the back section. The biological treatment tank is a two-tank continuous process with a denitrification tank at the front stage and a nitrification tank at the back stage, and is equipped with a circulating piping that returns the liquid from the nitrification tank to the denitrification tank. The biological treatment tank may be one that performs nitrification in one biological treatment tank and then denitrifies.

Biological treatment tank liquid or biological treatment tank effluent (below (Sometimes referred to as the "target liquid") the measured values of the amine and quaternary ammonium ion concentrations, and the adjustment of biological treatment conditions based on at least one of the measured values of the ammonium ion concentration, nitrate ion concentration, and nitrite ion concentration. For example, it is implemented in the following manner.

(1) When the sum of the measured values of the amine and quaternary ammonium ion concentrations of the target liquid and the measured values of the ammonium ion concentration exceeds the preset standard value, perform operation adjustment to improve nitrification.

(2) When the total of the measured value of the nitrate ion concentration and the measured value of the nitrite ion concentration of the target liquid exceeds a preset standard value, an operation adjustment to improve denitrification is performed.

Since the progress of the nitrification reaction during the denitrification treatment is a necessary prerequisite, when the above (1) condition is met, the corresponding (1) is preferred and the (2) is not performed. Only when the condition of (1) is not met, the correspondence of (2) is performed.

Operational adjustments to improve nitrification are carried out in the following priority order (1-1)→(1-2)→(1-3).

(1-1) In the step of carrying out the nitrification reaction, increase the aeration intensity to increase the dissolved oxygen concentration.

(1-2) For the time of the nitrification step, when the ratio to the time of the denitrification step can be adjusted, reduce the ratio (lengthen the time of the nitrification step).

(1-3) Increase the pH control target value.

Operational adjustments to improve denitrification are carried out in the following order of priority (2-1)→(2-2).

(2-1) Reduce the aeration intensity in the nitrification step to reduce the dissolved oxygen concentration.

(2-2) For the time of the nitrification step, when the ratio to the time of the denitrification step can be adjusted, increase the ratio (lengthen the time of the denitrification step).

When the sum of the measured values of the amine and quaternary ammonium ion concentration and the measured value of the ammonium ion concentration goes below the preset standard value, it is better to lower the pH control target.

By adjusting these biological treatment conditions, nitrification and denitrification can be carried out smoothly, and the pH control target value can be lowered. The addition amount of acid and inorganic flocculant can be reduced during the subsequent agglutination treatment. Process efficiently.

[Example]

The following examples illustrate the present invention in more detail.

[Example 1]

According to the present invention, the organic discharged water of the following water quality is subjected to nitrification and denitrification treatment.

<<Organic discharge water quality>>

pH: 9.5

NH ₄ -N concentration: 0.5mg-N/L

TMAH concentration: 15mg/L

TMA concentration: 0mg/L

DMA concentration: 2mg/L

MMA concentration: 3mg/L

Alkalinity: 7mg as CaCO ₃ /L

Na concentration: 3mg/L

The biological treatment tank uses a fluidized bed type nitrification and denitrification tank (with a carrier filling rate of 40%) for intermittent aeration, and performs nitrification and denitrification steps by repeating aeration and stopping aeration.

When the nitrification step is completed (when aeration is completed), the concentration of amine and level 4 ammonium ions in the tank liquid is periodically analyzed by ion column chromatography to analyze the total concentration of TMAH, TMA, DMA, MMA and ammonium ions (NH _4- N) concentration, nitrate ion (NO ₃ -N) concentration, nitrite ion (NO ₂ -N) concentration. From this result, the biological treatment conditions were adjusted by automatic control based on the following standard values.

<<Standard value>>

The upper limit of the concentration of amine and quaternary ammonium ions combined with the concentration of NH ₃ -N: 0.5 mg-N/L.

The upper limit of the sum of NO ₃ -N concentration and NO ₂ -N concentration: 3 mg-N/L.

pH control target value: upper limit 7.0~lower limit 6.0.

The maximum adjustment range of pH control target value per day: 0.1/day.

Operational adjustments to improve nitrification are carried out in the following order of priority.

(1) In the nitrification step, the dissolved oxygen concentration is increased by increasing the aeration intensity.

The dissolved oxygen concentration control target of the nitrification step is adjusted in the range of 3.0~6.0mg/L, and the maximum adjustment range of the dissolved oxygen concentration control target per day: 0.5mg/L/day.

(2) Reduce the ratio of the time of the denitrification step to the time of the nitrification step.

Adjust the denitrification step time/nitrification step time to the range of 0.1 to 0.9.

Operational adjustments to improve denitrification are performed in the following order of priority.

(3) In the denitrification step, the dissolved oxygen concentration is reduced by reducing the aeration intensity.

(4) Increase the time ratio of the denitrification step relative to the time of the nitrification step.

As a result, the obtained treated water quality is as shown in Table 1, and treated water with good water quality can be obtained.

After adding a polyferric sulfate solution as an inorganic flocculant to the treated water for flocculation, the addition amount of the inorganic flocculant necessary for RO membrane separation treatment is 110 mg/L, which can be greater than the following Comparative Examples 1 and 2 Reduce the amount added.

[Comparative Example 1]

In Example 1, intermittent aeration was not performed, and continuous aeration was performed to maintain the DO in the range of 3 to 4.0 mg/L, and only the nitrification step was performed. In addition, in order to For the constant nitration reaction, the pH was set to 7, and the treatment was performed under conditions higher than 6.5 in Example 1.

As a result, the TMAH of the quaternary ammonium salt was the same as in Example 1, and the decomposition was good. No residues of amines such as DMA, which produce intermediate metabolites of TMAH breakdown, were found. The TOC concentration of the treated water can maintain the same level of 3mg-C/L as in Example 1. As expected by setting the pH, the nitration reaction proceeded well and no NH ₄ -N residue was found. However, since the denitrification step is not performed, the residual concentrations of NO ₃ -N and NO ₂ -N are high, and the amount of NaOH that must be added to adjust the pH increases. As a result, the Na concentration increases.

In addition, as the pH setting increases, the alkalinity of the treated water increases, which increases the amount of the inorganic flocculant necessary to be added in the later stage.

[Comparative Example 2]

Except that the management of TMAH and amine concentration in Example 1 was not performed, the same treatment was performed.

As a result, there is no residue of NH ₄ -N, and since the residues of NO ₃ -N and NO ₂ -N are found, from the viewpoint of reducing the regular cost and the alkalinity of the treated water, the pH control target is set at 6.5 as a denitrification The reaction is actively controlled by aeration, and the ratio of the time of the denitrification step/the time of the nitrification step is increased to 0.4. As a result, the decomposition of TMAH deteriorated, and the TOC concentration of the treated water also increased to 7 mg-C/L.

In the case of this comparative example 2, the complete nitrification of nitrogen components in the discharged water cannot be achieved, which is the treatment requirement, accompanied by TMAH due to organic alkali components The TOC concentration in the remaining treated water increased, and the alkalinity was also higher than that in Example 1. As a result, the required addition amount of the inorganic flocculant in the later stage is increased.

From Table 1, the following items can be known.

With the present invention, the decomposition of amines and quaternary ammonium salts can be maintained well, and the concentration of (nitrite) nitrate ions in the treated water can be reduced meaningfully. As a result, the addition concentration of the alkali agent necessary for pH adjustment can be reduced. In addition, it can be operated while maintaining the decomposition range of amines and quaternary ammonium salts, lowering the pH control target value, and reducing the alkalinity of the treated water. Therefore, the addition amount of the acid agent and the inorganic coagulant in the subsequent coagulation step can be minimized.

In the above-mentioned embodiments, the fluidized bed type biological treatment method as the biological treatment is disclosed. However, due to the activated sludge method (AS), membrane separation activated sludge method (MBR), and activated sludge method with added support ( IFAS), etc. also have the same problem, using the original operation of the present invention Management law can also solve problems.

The present invention has been described in detail using specific embodiments, but the relevant industry will undoubtedly know that various changes can be made without departing from the intent and scope of the present invention.

This application is based on the Japanese Patent Application 2016-066065 filed on March 29, 2016, and is cited in its entirety.

Claims (14)

A biological treatment method, which is a method of introducing organic discharge water containing amines and/or grade 4 ammonium salts into a biological treatment tank for biological treatment, and is the amine of the biological treatment tank internal liquid or the biological treatment tank effluent And the measured value of the quaternary ammonium ion concentration, and the measured value of at least one of the ammonium ion concentration, the nitrate ion concentration, and the nitrite ion concentration as an indicator to adjust the biological treatment conditions, in which at least any of the following operation adjustments One: When the sum of the measured value of amine and grade 4 ammonium ion concentration and the measured value of ammonium ion concentration exceeds the reference value, the operation adjustment of the biological treatment tank to improve nitrification, and when the measured value of nitrate ion concentration and nitrite ion When the sum of the measured values of the concentration exceeds the reference value, the operation adjustment of the biological treatment tank for improving denitrification is performed. Such as the biological treatment method of claim 1, wherein the aforementioned biological treatment tank is a nitrification tank or a nitrification and denitrification tank. For the nitrification tank, adjust the nitrification conditions and/or pH control target value as the biological treatment conditions, and for the nitrification and denitrification tank , Adjust any of the nitrification conditions, denitrification conditions, and pH control target values as biological treatment conditions. The biological treatment method of claim 1 or 2, wherein the aforementioned biological treatment utilizes at least one selected from the group consisting of activated sludge method, membrane separation activated sludge method, fluidized bed biological treatment method, and activated sludge method with added support To process. Such as the biological treatment method of claim 1 or 2, wherein the aforementioned organic Drainage water is the drain water containing amines and/or grade 4 ammonium salts discharged from the semiconductor and liquid crystal manufacturing process. Such as the biological treatment method of claim 2, wherein the adjustment of the aforementioned nitrification conditions is to increase or decrease the dissolved oxygen concentration of the liquid in the aforementioned nitrification tank, increase or decrease the pH, or increase or decrease the nitrification time. Such as the biological treatment method of claim 2, wherein the adjustment of the denitrification conditions is to increase or decrease the dissolved oxygen concentration of the liquid in the nitrification tank, increase or decrease the pH, or increase or decrease the nitrification time. For example, in the biological treatment method of claim 2, in which the sum of the measured values of the aforementioned amine and quaternary ammonium ion concentration and the measured value of the ammonium ion concentration is below a preset standard value, the aforementioned pH control target value will be lowered. A biological treatment device, which is a biological treatment device containing amines and/or quaternary ammonium salts of organic discharge water, has a biological treatment tank into which the organic discharge water is introduced, and measures the or The first measuring means for the amine and 4-level ammonium ion concentration in the effluent of the biological treatment tank is at least one of the ammonium ion concentration, the nitrate ion concentration and the nitrite ion concentration in the biological treatment tank fluid or the biological treatment tank effluent A second measuring means, and a control means for adjusting the biological treatment conditions of the biological treatment tank based on the measured value of the first measuring means and the measured value of the second measuring means, wherein at least the following operation adjustments are performed Either: When the sum of the measured values of the amine and quaternary ammonium ion concentration and the measured value of the ammonium ion concentration exceeds the reference value, the operation of the biological treatment tank for improving nitrification Turn to adjustment, and when the sum of the measured value of the nitrate ion concentration and the measured value of the nitrite ion concentration exceeds the reference value, the operation adjustment of the biological treatment tank for improving denitrification is performed. Such as the biological treatment device of claim 8, wherein the aforementioned biological treatment tank is a nitrification tank or a nitrification and denitrification tank, and the aforementioned control means is a means to adjust the nitrification condition and/or pH control target value as the biological treatment condition when the nitrification tank is used ; In the nitrification and denitrification tank, it is a means to adjust any of the nitrification conditions, denitrification conditions and pH control target values as biological treatment conditions. The biological treatment device of claim 8 or 9, wherein the aforementioned biological treatment is selected from at least one of activated sludge treatment, membrane separation activated sludge treatment, fluidized bed biological treatment, and activated sludge treatment with added support. Such as the biological treatment device of claim 8 or 9, wherein the aforementioned organic discharge water system comes from discharge water containing amines and/or grade 4 ammonium salts discharged from the semiconductor and liquid crystal manufacturing process. Such as the biological treatment device of claim 9, wherein the aforementioned control means is used as the adjustment of the aforementioned nitrification conditions to increase or decrease the dissolved oxygen concentration of the liquid in the aforementioned nitrification tank, increase or decrease the pH, or increase or decrease the nitrification time. Such as the biological treatment device of claim 9, wherein the aforementioned control means is used to adjust the aforementioned denitrification conditions by increasing or decreasing the dissolved oxygen concentration of the liquid in the aforementioned nitrification tank, increasing or decreasing the pH, or increasing or decreasing the nitrification time. Such as the biological treatment device of claim 9, wherein the aforementioned control means When the sum of the amine and quaternary ammonium ion concentration measured by the aforementioned first measuring means and the measured value of the aforementioned ammonium ion concentration measured by the aforementioned second measuring means is below the preset standard value, the aforementioned pH will be lowered Means to control the target value.