JP2003117571A - Method for treating waste water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for economically and efficiently treating phenol compound-containing waste water produced form a process for manufacturing a polycarbonate resin until a low concentration of the phenol compound is attained. SOLUTION: In the method for treating phenol compound-containing waste water produced when the polycarbonate resin is manufactured, the waste water is brought into contact with ozone.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating wastewater produced when producing a polycarbonate resin. More specifically, the present invention relates to a method for treating wastewater containing a phenol compound generated during the production of a polycarbonate resin by contacting it with ozone.

[0002]

2. Description of the Related Art As a method for treating wastewater generated from a polycarbonate resin manufacturing process, (1) an activated sludge method by microorganisms, and (2) an adsorption method on activated carbon and ion exchange resins are generally used. There is.

As is well known, (1) the activated sludge method requires a long time for decomposing organic matters, and moreover, it is necessary to dilute the waste water to a concentration suitable for the growth of microorganisms. There is a drawback that the installation area is vast. (2) The adsorption method for activated carbon and ion exchange resin has a problem that the treatment operation is complicated and the adsorption life is short, so that the equipment and the treatment cost are expensive.

Further, in recent years, the production amount of polycarbonate resin has increased, the wastewater containing the phenol compound has increased accordingly, and the phenol compound to be disposed of has also increased, which is not preferable from the viewpoint of environmental protection and economically. Therefore, there is a demand for an industrial method that can economically and efficiently decompose and treat phenol compounds in wastewater to an extremely low concentration.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for economically and efficiently treating wastewater containing a phenol compound produced from a process for producing a polycarbonate resin to a low concentration.

The present inventor has conducted extensive studies to achieve the above-mentioned object, and as a result, in the method for treating wastewater containing a phenol compound produced in the production process of a polycarbonate resin, by using the ozone treatment method, the above-mentioned object is achieved. The inventors have reached the present invention by finding out what can be achieved.

[0007]

That is, according to the present invention, in a method for treating wastewater containing a phenolic compound produced during the production of a polycarbonate resin, the wastewater is brought into contact with ozone. Is provided.

The polycarbonate resin targeted by the present invention can be obtained, for example, by reacting a dihydric phenol with a carbonate precursor by a method such as an interfacial polymerization method or a melt polymerization method.

Typical examples of the dihydric phenol used here include hydroquinone, resorcinol, 4,
4'-dihydroxydiphenyl, 1,4-dihydroxynaphthalene, bis (4-hydroxyphenyl) methane,
Bis {(4-hydroxy-3,5-dimethyl) phenyl} methane, 1,1-bis (4-hydroxyphenyl)
Ethane, 1,1-bis (4-hydroxyphenyl) -1
-Phenylethane, 2,2-bis (4-hydroxyphenyl) propane (commonly called bisphenol A), 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane, 2,2-bis {(4- Hydroxy-3,5-dimethyl) phenyl} propane, 2,2-bis {(3,5-dibromo-4-hydroxy) phenyl} propane, 2,2
-Bis {(3-isopropyl-4-hydroxy) phenyl} propane, 2,2-bis {(4-hydroxy-3-)
Phenyl) phenyl} propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) -3-methylbutane, 2,2-bis (4
-Hydroxyphenyl) -3,3-dimethylbutane,
2,4-bis (4-hydroxyphenyl) -2-methylbutane, 2,2-bis (4-hydroxyphenyl) pentane, 2,2-bis (4-hydroxyphenyl) -4-
Methyl pentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -4-isopropylcyclohexane, 1,1-
Bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis {(4-hydroxy-3-methyl) phenyl} fluorene, α , Α'-bis (4-hydroxyphenyl) -o-diisopropylbenzene, α, α'-bis (4-hydroxyphenyl) -m
-Diisopropylbenzene, α, α'-bis (4-hydroxyphenyl) -p-diisopropylbenzene, 1,
3-bis (4-hydroxyphenyl) -5,7-dimethyladamantane, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxydiphenyl sulfide,
4,4'-dihydroxydiphenyl ketone, 4,4'-
Examples thereof include dihydroxydiphenyl ether and 4,4′-dihydroxydiphenyl ester.

Among these dihydric phenol compounds, bisphenol A, 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane, 2,2-bis (4-hydroxyphenyl) butane, 2, 2-bis (4
-Hydroxyphenyl) -3-methylbutane, 2,2-
Bis (4-hydroxyphenyl) -3,3-dimethylbutane, 2,2-bis (4-hydroxyphenyl) -4-
At least one selected from the group consisting of methylpentane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane and α, α'-bis (4-hydroxyphenyl) -m-diisopropylbenzene. A homopolymer or a copolymer obtained from two kinds of dihydric phenol compounds is preferable, and particularly, a homopolymer of bisphenol A and 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane and bisphenol are preferable. A, 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane or α, α'-bis (4-
A copolymer with hydroxyphenyl) -m-diisopropylbenzene is preferably used.

As the carbonate precursor, carbonyl halide, carbonic acid diester, haloformate or the like is used, and specific examples thereof include phosgene, diphenyl carbonate or dihaloformate of dihydric phenol.

In the production of a polycarbonate resin by the interfacial polymerization method of the above-mentioned dihydric phenol and carbonate precursor, a catalyst, a terminal terminator, an antioxidant of the dihydric phenol and the like may be used if necessary. . Further, the polycarbonate resin may be a branched polycarbonate resin obtained by copolymerizing a trifunctional or higher polyfunctional aromatic compound, or a polyester carbonate resin obtained by copolymerizing an aromatic or aliphatic difunctional carboxylic acid, It may also be a mixture of two or more of the obtained polycarbonate resins.

The reaction by the interfacial polymerization method is usually a reaction between a dihydric phenol and phosgene, which is carried out in the presence of an acid binder and an organic solvent. As the acid binder, for example, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, pyridine or the like is used.

As the organic solvent, for example, a halogenated hydrocarbon such as methylene chloride or chlorobenzene is used.

In order to accelerate the reaction, for example, triethylamine, tetra-n-butylammonium bromide,
It is also possible to use a catalyst such as a tertiary amine such as tetra-n-butylphosphonium bromide, a quaternary ammonium compound, a quaternary phosphonium compound or the like. The reaction temperature is usually 0 to 40 ° C., the reaction time is preferably 10 minutes to 5 hours, and the pH during the reaction is preferably maintained at 9 or higher.

As the terminal terminator, monofunctional phenols are preferably used. The polycarbonate resin obtained by using the terminal stopper is excellent in heat resistance as compared with the polycarbonate resin obtained because the terminal is blocked by a group based on a monofunctional phenol.

Specific examples of such monofunctional phenols include phenol, p-cresol, p-ethylphenol, p-isopropylphenol, p-tert-butylphenol, p-cumylphenol, p-cyclohexylphenol and p-octylphenol. , P-nonylphenol, 2,4-xylenol, p-methoxyphenol, p-hexyloxyphenol, p-decyloxyphenol, o-chlorophenol, m-chlorophenol, p-chlorophenol, p-bromophenol, pentabromo. Phenol, pentachlorophenol, p-phenylphenol, p-isopropenylphenol, 2,4-di (1'-methyl-1'-phenylethyl) phenol, β-naphthol, α-naphthol,
p- (2 ', 4', 4'-trimethylchromanyl) phenol, 2- (4'-methoxyphenyl) -2-
Examples thereof include phenols such as (4 ″ -hydroxyphenyl) propane, and preferably phenol and p-ter.
t-butylphenol and p-cumylphenol,
Particularly preferred is p-tert-butylphenol.

It is desirable that these terminal terminators are introduced at the terminal of at least 5 mol%, preferably at least 10 mol% based on all the terminals of the obtained polycarbonate resin, and the terminator is used alone. Or you may use it in mixture of 2 or more types.

The reaction by the melt polymerization method is usually a transesterification reaction between a dihydric phenol and a carbonic acid diester, and the dihydric phenol and the carbonic acid diester are mixed in the presence of an inert gas, and usually at 120 to 350 ° C. under reduced pressure. React. The degree of pressure reduction is changed stepwise, and finally the phenols produced at 133 Pa or less are removed to the outside of the system. The reaction time is usually about 1 to 4 hours.

Examples of the carbonic acid diester include diphenyl carbonate, dinaphthyl carbonate, bis (diphenyl) carbonate, dimethyl carbonate, diethyl carbonate and dibutyl carbonate. Of these, diphenyl carbonate is preferred.

A polymerization catalyst can be used to accelerate the polymerization rate. Examples of the polymerization catalyst include hydroxides of alkali metals and alkaline earth metals such as sodium hydroxide and potassium hydroxide, and waters of boron and aluminum. Oxides, alkali metal salts, alkaline earth metal salts, quaternary ammonium salts, alkali metal or alkaline earth metal alkoxides, alkali metal or alkaline earth metal organic acid salts, zinc compounds, boron compounds, silicon compounds, Examples of the catalyst that are usually used for esterification reaction or transesterification reaction of germanium compound, organotin compound, lead compound, antimony compound, manganese compound, titanium compound, zirconium compound and the like. The catalyst may be used alone or in combination of two or more kinds.

Further, in the polymerization reaction, in order to reduce the phenolic terminal groups, for example, 2-chlorophenylphenyl carbonate, 2-methoxycarbonylphenylphenyl carbonate and 2-ethoxycarbonylphenylphenyl carbonate can be used in the latter stage or after the termination of the polycondensation reaction. It is preferable to add a compound such as carbonate.

Regarding the details of the reaction formats other than the above, the formats well known per se can be adopted.

The viscosity average molecular weight (M) of the polycarbonate resin is preferably 10,000 to 100,000, more preferably 12,000 to 50,000, more preferably 1
More preferably, it is 3,000 to 40,000. A polycarbonate resin having such a viscosity average molecular weight is preferable because sufficient strength can be obtained, melt flowability at the time of molding is also good, and molding distortion does not occur. The viscosity average molecular weight is 100 ml of methylene chloride and 0.7 of polycarbonate resin.
It is obtained by inserting the specific viscosity (η _sp ) obtained from a solution of g dissolved at 20 ° C. into the following equation.

Η _sp /c=[η]+0.45×[η] ² c
(Where [η] is the intrinsic viscosity) [η] = 1.23 × 10 ⁻⁴ M ^0.83 c = 0.7 As the phenol compound contained in the wastewater treated in the present invention, it is used as a raw material of the polycarbonate resin. Examples thereof include dihydric phenol components, monofunctional phenol components used as terminal stoppers, and phenol compounds contained as decomposition products or impurities thereof. Among them, bisphenol A, phenol, p-tert
-Butylphenol is suitable as the target phenolic compound.

The wastewater treatment method of the present invention is preferably used particularly for wastewater generated in the manufacturing process of the above-mentioned interfacial polymerization method.

Taking the interfacial polymerization method as an example, the steps for producing the polycarbonate resin include a reaction step, a polymerization step, a refining step, a granulating step, a drying step and a melt extrusion step. Waste water containing is generated.

Specifically, a method of adding an aqueous phase after the polymerization from the polymerization step, water used for washing in the purification step, and a polycarbonate solution to the warm water in the granulation step is usually used. The hot water, the water evaporated during the drying process in the drying process, and the liquid sealing water of the venting vacuum pump of the extruder in the melt extrusion process serve as drainage. Among them, the aqueous phase after the polymerization generated from the polymerization step and the liquid sealing water of the vent vacuum pump in the melt extrusion step are typically processed, and particularly the aqueous phase after the polymerization generated from the polymerization step is preferably processed. It

The method for treating wastewater used in the present invention has, for example, an air diffuser 4 as shown in FIG. 1, a reaction tank 3 for containing a certain amount of wastewater containing a phenolic compound, and ozone to be injected into the reaction tank. A processing device provided with an ozone generator 2, a pump 7 for supplying the waste water to be sent to the reaction tank, and an exhaust ozone processing machine 5 for detoxifying unreacted ozone in the reaction tank and discharging the ozone to the outside is preferably used.

The concentration of the phenol compound contained in the waste water after the ozone treatment is preferably 300 ppb or less, more preferably 100 ppb or less, further preferably 50 ppb or less, particularly preferably 20 ppb or less.

In the treatment method of the present invention, the ozone treatment may be used in combination with a treatment with an ion exchange resin or a treatment with activated carbon. In particular, it is preferable to perform the activated carbon treatment before the ozone treatment because the phenol compound contained in the waste water can be removed to some extent, and the ozone treatment burden such as a small amount of ozone decreases during the ozone treatment.

The concentration of the phenol compound contained in the wastewater to be treated is preferably 100 ppb to 3500 ppm, more preferably 100 to 8000 ppb, and 100 to 8000 ppb.
5000 ppb is particularly preferred. It is preferable to treat the wastewater having a concentration of the phenol compound contained in the wastewater of 100 ppb to 3500 ppm with ozone because the treatment efficiency is good and the running cost and the equipment cost are low.

The pH of the waste water to be treated is preferably 4 to 12, more preferably 5 to 10, and particularly preferably 6 to 10. When the pH is 4 or more, a device having corrosion resistance is not required and the equipment cost is low, which is preferable. Further, when the pH is 12 or less, the self-decomposition rate of ozone is slow and the decomposition efficiency of the phenol compound is good, which is preferable.

The ozone consumption is 2 per 1 m ^{3 of} wastewater.
It is desirable to be 50 g. What is ozone consumption?
It is the amount of ozone consumed in the wastewater, which is the total amount of the amount consumed for the decomposition of phenolic compounds and the amount consumed for self-decomposition. This ozone consumption is obtained from the difference between the introduced ozone amount and the discharged ozone amount. When the amount of ozone consumed is 2 to 50 g per 1 m ³ of drainage, it is preferable because the treatment efficiency is good and the running cost and facility cost are low.

The temperature of waste water when contacting ozone is 0 to 4
5 degreeC is preferable and 10-40 degreeC is more preferable. When the drainage temperature at the time of contacting with ozone is 0 to 45 ° C., ozone self-decomposition is reduced, treatment efficiency is good, and running cost and facility cost are low, which is preferable.

The neutral salt concentration in the waste water when contacting with ozone is preferably 1 to 300 g per liter of waste water, and 10
-200g is more preferable. As a typical example of the neutral salt, sodium chloride generated in the production process of polycarbonate is cited. The hole diameter of the air diffuser is 40 to 400.
μm is desirable. Neutral salt concentration in wastewater is 1 to 300 g /
If the pore size of the air diffuser is 40 to 400 μm in 1, the ozone-containing bubbles are sufficiently small without forming bubbles in the waste water,
The contact area between the wastewater and the ozone-containing bubbles is large, the treatment efficiency is good, and the running cost and equipment cost are low, which is preferable.

When ozone is injected using a diffuser, the components in the waste water or the components generated by ozone may adhere to the inside, inside or outside of the diffuser tube.
In that case, water, water vapor, an inert gas or a mixture thereof can be injected from the inside of the diffuser tube to remove the adhered or precipitated components. The water may be heated water or drainage. Further, air or nitrogen is exemplified as the inert gas.

[0038]

EXAMPLES The present invention will be further described below with reference to examples. The phenol compound concentration and sodium chloride concentration were determined by the following methods. (1) Concentration of bisphenol A, p-tert-butylphenol, phenol; 4 ml of ultrapure water in 2 ml of sample
A solution obtained by mixing 1 and 4 ml of acetonitrile was measured using a liquid chromatograph with a fluorescence detector (manufactured by Waters). In addition, bisphenol A, p-tert-
Butylphenol and phenol detection limit is 3
ppb. (2) Sodium chloride concentration; measured by the Holhard method. Specifically, a small excess of AgNO ₃ standard solution was added to the sample solution to precipitate AgCl, iron alum and nitrobenzene were added to the filtrate, and titration was performed with a NH ₄ SCN standard solution, and chlorination was performed according to the amount of AgNO ₃ consumed. The amount of sodium was determined.

Example 1 Using the apparatus shown in FIG. 1,
A reaction tank having a width of 4 m, a depth of 2.8 m, and a height of 5.8 m contains a phenol compound which is a water phase after completion of polymerization of a polycarbonate resin produced by an interfacial polymerization method (bisphenol A concentration 250 ppb, p-tert-butylphenol). Concentration 1500ppb, Phenol concentration 450pp
b), sodium chloride concentration 110 g / l, pH 7.5,
Waste water at a temperature of 35 ° C is passed at a flow rate of 150 m ³ / hr, and the amount of ozone generated from the ozonizer is 10
0g / Nm ³ × 25Nm ³ / hr (generated pressure 0.1MP
The ozone of a) was diffused into the waste water by the diffused method (ceramic IAP filter: pore size 100 μm), and the phenol compound and the catalytic oxidation treatment were continuously performed. The amount of unreacted ozone was 35 g / Nm ³ × 25 Nm ³ / hr. Table 2 shows the amount of each phenolic compound in the wastewater after ozone treatment.

[Example 2] Using the same processing apparatus as in Example 1, a polycarbonate resin was produced by an interfacial polymerization method, which contained a phenol compound in an aqueous phase after completion of the polymerization (bisphenol A concentration: 3700 ppb, p-tert-butylphenol). Concentration 1600 ppb, phenol concentration 44
0ppb), sodium chloride concentration 100g / l, pH
Waste water at a temperature of 30 ° C. of 7.5 is passed at a flow rate of 140 m ³ / hr, and the amount of ozone generated from the ozonizer is 100 g / Nm ³ × 25 Nm ³ / hr (generated pressure of 0.
Ozone (1 MPa) was diffused into the waste water by a diffuser method (ceramic IAP filter: pore size 100 μm) to continuously perform a catalytic oxidation treatment with a phenol compound. The amount of unreacted ozone was 32 g / Nm ³ × 25 Nm ³ / hr.
Table 2 shows the amount of each phenolic compound in the wastewater after ozone treatment.

[Example 3] Using the same processing apparatus as in Example 1, a polycarbonate resin was produced by an interfacial polymerization method, which contained a phenol compound in an aqueous phase after completion of polymerization (bisphenol A concentration: 200 ppb, p-tert-butylphenol). Concentration 1500ppb, Phenol concentration 420
ppb), sodium chloride concentration 100 g / l, pH 7.
5. The wastewater at a temperature of 31 ° C. is passed at a flow rate of 380 m ³ / hr, and the ozone amount generated by the ozonizer is 100 g / Nm ³ × 25 Nm ³ / hr (generated pressure 0.1 M
Ozone (Pa) was diffused into the wastewater by an air diffusion method (ceramic IAP filter: pore size 100 μm), and a phenol compound and a catalytic oxidation treatment were continuously performed. The amount of unreacted ozone was 30 g / Nm ³ × 25 Nm ³ / hr. Table 2 shows the amount of each phenolic compound in the wastewater after ozone treatment.

[Example 4] Using the same processing apparatus as in Example 1, a polycarbonate resin was produced by an interfacial polymerization method, which contained a phenol compound in an aqueous phase after completion of the polymerization (bisphenol A concentration: 240 ppb, p-tert-butylphenol). Concentration 1800 ppb, phenol concentration 450
ppb), sodium chloride concentration 110 g / l, pH 7.
5. While passing wastewater with a temperature of 48 ° C at a flow rate of 155 m ³ / hr, the ozone amount generated by the ozonizer is 100 g / Nm ³ × 25 Nm ³ / hr (generated pressure 0.1 M
Ozone (Pa) was diffused into the wastewater by an air diffusion method (ceramic IAP filter: pore size 100 μm), and a phenol compound and a catalytic oxidation treatment were continuously performed. The amount of unreacted ozone was 34 g / Nm ³ × 25 Nm ³ / hr. Table 2 shows the amount of each phenolic compound in the wastewater after ozone treatment.

[Example 5] Using the same processing apparatus as in Example 1, mixed drainage of a water phase after completion of polymerization of a polycarbonate resin produced by an interfacial polymerization method and liquid sealing water of a vacuum pump for venting in a melt extrusion process (A bisphenol A concentration of 250 ppb, p-tert-
Butylphenol concentration 1700 ppb, phenol concentration 410 ppb), sodium chloride concentration 0.2 g / l,
While passing wastewater having a pH of 7.5 and a temperature of 32 ° C. at a flow rate of 150 m ³ / hr, ozone generated from the ozonizer has an ozone amount of 100 g / Nm ³ × 25 Nm ³ / hr (generated pressure 0.1 MPa). Aeration method (ceramic IA
A P filter was used to diffuse air into the wastewater with a pore size of 100 μm, and a phenol compound and contact oxidation treatment were continuously performed. The amount of unreacted ozone was 72 g / Nm ³ × 25 Nm ³ / hr. Table 2 shows the amount of each phenolic compound in the wastewater after ozone treatment.

[Example 6] Using the same processing apparatus as in Example 1, a polycarbonate resin was produced by an interfacial polymerization method, which contained a phenol compound in an aqueous phase after completion of the polymerization (bisphenol A concentration: 230 ppb, p-tert-butylphenol). Concentration 1400ppb, Phenol concentration 430
ppb), sodium chloride concentration is 105 g / l, pH
Waste water at a temperature of 33 ° C. of 7.5 is passed at a flow rate of 145 m ³ / hr, and the amount of ozone generated from the ozonizer is 100 g / Nm ³ × 25 Nm ³ / hr (generated pressure of 0.
Ozone (1 MPa) was diffused into the waste water by a diffuser method (ceramic IAP filter: pore diameter 1 mm), and the phenol compound and the catalytic oxidation treatment were continuously performed. The amount of unreacted ozone was 63 g / Nm ³ × 25 Nm ³ / hr. Table 2 shows the amount of each phenolic compound in the wastewater after ozone treatment.

[Example 7] A polycarbonate resin produced by an interfacial polymerization method containing a phenol compound which is an aqueous phase after completion of polymerization (bisphenol A concentration: 250 ppb,
p-tert-butylphenol concentration 1500 ppb,
Phenol concentration 450 ppb) Sodium chloride concentration 11
Waste water of 0 g / l, pH 7.5, and temperature of 35 ° C. is passed through an activated carbon filling tank to obtain a bisphenol A concentration of 25 ppb, p-
tert-Butylphenol concentration 150 ppb, phenol concentration 40 ppb, sodium chloride concentration 110 g /
Waste water having a temperature of 35 ° C. was obtained. Using the same ozone treatment apparatus as in Example 1, the resulting wastewater was passed at a flow rate of 150 m ³ / hr, and the amount of ozone generated from the ozonizer was 100 g / Nm ³ × 5 Nm ³ / hr (generated pressure 0.1
(MPa) ozone was diffused into the wastewater by a diffuser method (ceramic IAP filter: pore size 100 μm), and the phenol compound and the catalytic oxidation treatment were continuously performed. The amount of unreacted ozone was 35 g / Nm ³ × 5 Nm ³ / hr. Table 2 shows the amount of each phenolic compound in the wastewater after ozone treatment.

[0046]

[Table 1]

[0047]

[Table 2]

[0048]

EFFECT OF THE INVENTION In the method for treating wastewater generated from the production process of the polycarbonate resin of the present invention, the concentration of the phenol compound contained in the wastewater is reduced to an extremely low concentration by subjecting ozone and the wastewater to the contact oxidation treatment, The industrial effect it produces is exceptional.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing the configuration and treatment system of an ozone treatment apparatus suitable for carrying out the method of the present invention.

[Explanation of symbols] 1. Oxygen booster blower 2. Ozone generator 3. Reaction tank 4. Air diffuser 5. Ozone killer 6. Suction blower 7. Drainage pump 8. Drainage U-tube 9. Drainage outlet

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Akira Manabe             1-2-2 Uchisaiwaicho, Chiyoda-ku, Tokyo             Human Kasei Co., Ltd. (72) Inventor Koji Ishihata             1-2-2 Uchisaiwaicho, Chiyoda-ku, Tokyo             Human Kasei Co., Ltd. (72) Inventor Takashi Kono             Sumitomo Precision Works 1-10 Fuso-cho, Amagasaki City, Hyogo Prefecture             Business (72) Inventor Kazuo Tanaka             Sumitomo Precision Works 1-10 Fuso-cho, Amagasaki City, Hyogo Prefecture             Business (72) Inventor Shingo Shibata             Sumitomo Precision Works 1-10 Fuso-cho, Amagasaki City, Hyogo Prefecture             Business F-term (reference) 4D024 AA04 AB04 BA02 BA17 DB24                 4D050 AA13 AB15 BB02 BD02 CA06                       CA13

Claims (12)

[Claims] 1. A method for treating wastewater containing a phenolic compound produced during the production of a polycarbonate resin, which comprises contacting the wastewater with ozone. 2. The method for treating wastewater according to claim 1, wherein the concentration of the phenol compound contained in the wastewater is 100 ppb to 3500 ppm. 3. Ozone consumption is 2 per 1 m ^{3 of} wastewater.
The method for treating wastewater according to claim 1, wherein the amount is 50 g. 4. The temperature of wastewater when contacting ozone is 0.
The method for treating wastewater according to claim 1, which has a temperature of about 45 ° C. 5. The method for treating wastewater according to claim 1, wherein the neutral salt concentration in the wastewater when contacting with ozone is 1 to 300 g / l. 6. The method for treating wastewater according to claim 1, wherein the phenol compound is phenol, bisphenol A or p-tert-butylphenol. 7. The method for treating wastewater according to claim 1, wherein the concentration of the phenol compound in the wastewater treated by the method for treating wastewater is 300 ppb or less. 8. The method for treating wastewater according to claim 1, wherein the concentration of the phenol compound in the wastewater treated by the method for treating wastewater is 20 ppb or less. 9. A reaction tank having an air diffuser for accommodating a certain amount of the waste water, an ozone generating section for generating ozone to be injected into the reaction tank, a pouring section for the waste water to be sent to the reaction tank, and a non-existent inside the reaction tank 2. The method for treating wastewater according to claim 1, wherein a treatment device provided with a waste ozone treatment unit that detoxifies the reaction ozone and discharges it to the outside is used. 10. The method for treating wastewater according to claim 9, wherein the air diffuser has a hole diameter of 40 to 400 μm. 11. The method for treating wastewater according to claim 1, wherein the wastewater is treated with activated carbon, and the activated carbon-treated wastewater is contacted with ozone. 12. A method for treating wastewater containing a phenolic compound produced during the production of a polycarbonate resin, which comprises injecting ozone into the wastewater through an air diffuser to treat the wastewater, in which case the diffuser tube is treated. A method for removing adhered or precipitated components of an air diffuser characterized by injecting water, steam, an inert gas or a mixture thereof from the inside of the air diffuser to remove the adhered or precipitated components.