JP2001029966A - Method and apparatus for treating organic wastewater containing endocrine disturbing substance or carcinogen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and apparatus for treating an org. wastewater containing an endocrine disturbing substance or a carcinogen to decompose and remove the endocrine disturbing substance or the carcinogen. SOLUTION: Ozone and hydrogen peroxide are injected in and added to water to be treated by an ejector system to decompose a part of a substance to be treated at first and the treated mixed water is subsequently introduced into an ozone reaction tank 4 to decompose and remove the substance to be treated in the same way and the treated water of the ozone reaction tank is further introduced into an ultraviolet reaction tank 12 to be irradiated with ultraviolet rays in the presence of ozone and hydrogen peroxide to decompose the substance to be treated and a part of the treated water of the ultraviolet reaction tank 12 is returned to the ultraviolet reaction tank 12 while hydrogen peroxide and the waste ozone 10 of the ozone reaction tank 4 are injected in and added to the treated water by an ejector system to uniformize the treated water in the ultraviolet reaction tank 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the treatment of organic wastewater containing endocrine disruptors or carcinogens, and more particularly to a method of treating organic wastewater that can be used for leachate or industrial wastewater treatment. It relates to a processing device.

[0002]

2. Description of the Related Art Conventionally, as a main treatment method for organic wastewater such as leachate, a treatment method mainly for removing organic substances has been used. The main treatment methods are biological treatment to remove BOD and nitrogen, coagulation and precipitation treatment to remove chromaticity, COD and SS, and sand filtration treatment to remove suspended substances such as SS. There is. Further, as an advanced treatment method, activated carbon treatment may be used. However, any of the above treatment methods has little effect of decomposing and removing endocrine disrupting substances or carcinogenic substances, which are trace harmful substances in organic wastewater, and endocrine disrupting substances or carcinogenic substances often remain in effluent water. Was. Furthermore, many endocrine disrupting substances or carcinogenic substances are almost insoluble in water, and even if the content of the substance in the treated water decreases in each treatment step, most of the substance is contained in the sludge generated from the treatment step. After the dehydration treatment, the content of the substance in the cake is high, and it is considered that there is not much effect of decomposing and removing endocrine disrupting substances or carcinogenic substances in the whole system.

As a recent technique for decomposing trace harmful substances, it is known that the trace harmful substances are decomposed and removed by an oxidation reaction by an accelerated oxidation method in which ozone is injected and ultraviolet or hydrogen peroxide is injected.

[0004]

However, when ultraviolet irradiation or ozone injection is introduced into organic wastewater having a high concentration of suspended substances, chromaticity components, and organic substances, the ultraviolet light transmittance is low, and accelerated oxidation with ozone occurs. It is considered that the reaction rate decreased and the generation of hydroxyl radical was not sufficient. In addition, when adding hydrogen peroxide, the injection rate of hydrogen peroxide is affected by the ozone dissolution efficiency and the state of the water to be treated, so that it is often difficult to control the injection rate in the single-stage treatment. Further, there is a problem that the waste ozone treatment when the ozone dissolution efficiency is reduced leads to an increase in treatment cost.

[0005] The present invention solves the above-mentioned problems. In an ozone reactor for injecting ozone and hydrogen peroxide into water to be treated, an endocrine disrupting substance or a carcinogenic substance to be treated is sufficiently reduced. In addition to decomposing and removing, the treated water discharged from the ozone reaction tank is treated by using the ozone discharged from the ozone reaction tank, thereby efficiently decomposing and removing endocrine disrupting substances or carcinogenic substances, and releasing the discharged ozone. To provide a processing method and a processing apparatus that do not need to separately perform processing for the above.

[0006]

The inventor of the present invention has studied various methods for solving the above-mentioned problems, and has taken measures to increase the reaction rate of ozone with respect to the water to be treated, and has taken out of the ozone reaction tank. It has been found that it is effective to utilize ultraviolet irradiation in order to make the exhausted ozone efficiently act on the reaction with the water to be treated, and based on this, the present invention has been achieved. The present invention has solved the above-mentioned problems by a method for treating organic wastewater containing the following endocrine disrupting substance or carcinogen and an apparatus therefor.

That is, the present invention has the following configuration. (1) A method for treating an organic wastewater containing an endocrine disrupting substance or a carcinogen, wherein ozone is injected into the water to be treated by an ejector method, hydrogen peroxide is added, and the mixture is introduced into an ozone reaction tank. The reaction is carried out in the reaction tank, and then the treated water of the ozone reaction tank is introduced into the ultraviolet irradiation reaction tank to cause a reaction. A method for treating organic wastewater, wherein the organic wastewater is returned to an ultraviolet irradiation reaction tank while hydrogen is injected and added. (2) The method for treating organic wastewater according to the above (1), wherein a pressure regulating valve is provided in a pipe at an exhaust ozone gas outlet and a treatment outlet of the ozone reaction tank so that the pressure in the ozone reaction tank can be adjusted to be high. . (3) The endocrine disrupting substance or carcinogen is dioxin, bisphenol A, dioxane or diphthalic acid (2
-Ethylhexyl), wherein (1)
Or the organic wastewater treatment method according to (2).

(4) An organic wastewater treatment apparatus containing an endocrine disrupting substance or a carcinogen, which has an ozone suction ejector connected to an ozone generator and connected to a hydrogen peroxide supply pipe on the way. A treated water inflow pipe having a tip inserted into the ozone reaction vessel, an ozone reaction vessel treated water outflow pipe and an ozone discharge pipe at an upper part, and an ozone reaction vessel treated water circulation pipe communicating with the treated water inflow pipe at a lower part. Connected ozone reaction tank, ultraviolet lamp suspended from the top, ozone reaction tank treated water outflow pipe, ultraviolet reaction tank treated water outflow pipe and ozone discharge pipe at the top, and ozone discharge pipe of ozone reaction tank at the bottom And an ultraviolet reactor ejector connected to a hydrogen peroxide injection tube for the ultraviolet reactor, which branches off from the ultraviolet reactor treated water outflow pipe, and has a purple end inserted into the ultraviolet reactor. Processor of organic waste water, characterized in that is constituted by the ultraviolet radiation reaction vessel equipped with a line reactor treated water circulation pipe. (5) The organic wastewater treatment apparatus according to the above (4), wherein a pressure adjusting valve is provided in a pipe of an ozone gas outlet and a treated water outlet of the ozone reaction tank.

[0009]

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, for organic wastewater containing endocrine disrupting substances or carcinogenic substances, first, water to be treated is introduced into an ozone reaction tank and reacted with ozone. At the time, ozone gas is dissolved in water with high dissolution efficiency by injecting ozone with the ejector method and oxidizing by adding hydrogen peroxide, and many OH radicals with strong oxidizing power are generated in coexistence with hydrogen peroxide In addition to decomposing and removing contaminants that absorb ultraviolet light during UV irradiation, such as organic substances and chromaticity components in the water to be treated, it also decomposes part of endocrine disrupting substances or carcinogenic substances in the water to be treated. Can be removed. In addition, by adjusting the pressure inside the ozone reaction tank to a high level, unreacted ozone and residual hydrogen peroxide inside the ejector are removed inside the ozone reaction tank.
Similarly, it reacts with endocrine disrupting substances or carcinogenic substances in the water to be treated, and can be decomposed and removed with high efficiency together with organic substances and chromaticity components in the water to be treated. Further, by returning the treatment mixture from the ozone reaction tank treated water circulation pipe communicating from the bottom of the ozone reaction tank to the treated water inflow pipe, it is possible to cope with fluctuations in the amount of raw water to be treated and the load.

[0010] The ozone reaction tank treated water obtained as described above is subjected to endocrine secretion remaining in the ozone reaction tank treated water by adding hydrogen peroxide and injecting ozone discharged from the ozone reaction in a UV reaction tank that performs ultraviolet irradiation. Disruptors or carcinogens can be decomposed and removed. In particular, since the water to be treated was subjected to removal of organic substances and chromaticity components in the ozone reaction tank,
In the UV reaction tank, the transmittance of ultraviolet rays increases, and the generation of OH radicals due to the irradiation of ultraviolet rays during injection of ozone and hydrogen peroxide increases, while the ozone reaction tank decomposes due to insufficient hydrogen peroxide and other factors. Even if there is residual ozone that has not contributed, it can be efficiently dissolved in the UV reaction tank in the coexistence of hydrogen peroxide and ultraviolet light to decompose and remove the endocrine disrupting substance or the carcinogenic substance as the target substance.

Further, by returning the treated water of the UV reaction tank to the UV reaction tank again by the circulation pump,
The uniformity in the reaction tank is achieved, and the UV irradiation effect is enhanced in the coexistence with ozone and hydrogen peroxide, so that the decomposition efficiency of the UV reaction tank can be improved. In addition, when an organic chlorine compound such as dioxins is to be treated, the highly chlorinated organic compound is reduced in chlorine by UV irradiation, and the low chlorinated organic compound is completely decomposed by injection of ozone and hydrogen peroxide. The decomposition efficiency for the water to be treated increases.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings showing an embodiment, but the present invention is not limited to this embodiment.

Embodiment 1 FIG. 1 is a flow sheet showing an example of the processing method according to the present invention. As shown in FIG. 1, the water to be treated is directly supplied from the treated water pipe 1 to the ejector injection pipe 2 and sent to the ejector 6 from the ejector injection pump 3, where the ozone gas 7 from the ozone generator 19 is also injected. By injecting hydrogen peroxide from the H ₂ O ₂ injection pipe 5 for the ozone reaction tank into the ejector injection pipe 2, the organic matter in the water to be treated, the chromaticity component and the target endocrine disrupting substance or carcinogen in the ejector 6 are treated. Part of the material was decomposed and removed. The mixed treatment water that has exited the ejector flows into the ozone reaction tank 4. In the ozone reaction tank 4 as well, since the pressure in the reaction tank 4 can be maintained high by adjusting the exhaust ozone pressure control valve 8 and the treated water outlet pressure control valve 9, the dissolution rate of O ₃ and the reaction with H ₂ O ₂ Was promoted, generation of hydroxyl radical (OH.) Was increased, and reaction efficiency was improved.

The treated water 11 from the ozone reaction tank 4 that has exited the ozone reaction tank 4 is introduced into a UV reaction tank 12, where hydrogen peroxide is added from a UV reaction tank H ₂ O ₂ injection pipe 15 and the ozone reaction The exhausted ozone 10 from the tank 4 is also introduced into the UV reaction tank 12 through the ejector 13 for the UV reaction tank 12. Here, by the irradiation of the UV lamp 14 and the injection of ozone and hydrogen peroxide, the reaction proceeds effectively, and the endocrine disrupting substance or carcinogenic substance remaining in the treated water 11 of the ozone reaction tank is decomposed and removed. The treated water obtained from the UV reactor 12 is used as the final treated water 18, and a part of the treated water 18 is returned to the UV reactor 12 by the ejector circulation pump 17.
The inside of the V reaction tank is made uniform. Although the ozone concentration of the exhausted ozone 16 from the UV reaction tank is reduced, it is released to the atmosphere via an exhausted ozone treatment device (not shown).

An organic wastewater containing an endocrine disrupting substance or a carcinogenic substance was treated by the method shown by the flow sheet in FIG. Table 1 shows the quality of the water to be treated by this method and the quality of the treated water obtained in each treatment step.
Table 2 shows the processing conditions of the ozone reaction tank and the UV reaction tank.

[0016]

[Table 1]

[0017]

[Table 2]

As shown in Table 1, the water to be treated has a chromaticity of 100.
Turbidity, turbidity 50 degrees, COD 150 mg / l, whereas the treated water obtained from the ozone reaction tank has chromaticity 20 degrees, turbidity 5 degrees, COD 100 mg / l, and the chromaticity and turbidity components are largely removed. In addition to what was done, COD was about 33
% Could be removed. Total dioxin is 3500
pg / liter to about 1500 pg / liter, TE
Q-converted value is from 46 pg / liter of treated water to 13 p
g / liter. In addition, dioxane is converted from 6500 ng / liter of the water to be treated to 2300 n
g / liter, bisphenol A is 500
ng / liter to 180 ng / liter, respectively.
A decomposition rate of around 0% was obtained.

Further, in the second stage UV reactor, 20 mg / liter of ozone discharged from the ozone reactor is introduced, the H ₂ O ₂ injection rate is 5 mg / liter, and the UV irradiation amount is 0.1 mm.
As a result of the treatment under the condition of 75 W · h / liter, the total dioxin of the treated water was 1500 pg at the entrance of the UV reaction tank.
/ Liter to 400 pg / liter, and the TEQ conversion value also decreased from 13 pg / liter at the inlet to 3.5 pg / liter. In addition, dioxane is 2
Bisphenol A decreased from 300 ng / L to 450 ng / L, and from 180 ng / L to no detection, respectively. The exhaust ozone at the outlet of the UV reactor also has an ozone concentration of 2 mg / liter and an ozone consumption rate of 98.
%. For this reason, the treatment of the discharged ozone is also facilitated.

[0020]

As shown in the examples, according to the present invention, for the organic wastewater containing endocrine disrupting substances or carcinogenic substances, first, the water to be treated is introduced into an ozone reaction tank, and the ozone is treated by an ejector method. Ozone gas is dissolved in water with high dissolving efficiency by adding hydrogen peroxide and performing oxidation treatment by adding hydrogen peroxide, and a large amount of OH radicals having strong oxidizing power are generated in coexistence with hydrogen peroxide. In addition to decomposing and removing contaminants such as organic substances and chromaticity components in the treated water that interfere with UV irradiation, it can also decompose and remove some endocrine disrupting substances or carcinogenic substances in the treated water. In addition, by adjusting the pressure inside the ozone reaction tank to a high level, unreacted ozone and residual hydrogen peroxide inside the ejector also react with endocrine disrupting substances or carcinogenic substances in the water to be treated in the ozone reaction tank. However, it can be decomposed and removed with high efficiency together with organic substances and chromaticity components in the water to be treated.

The treated water of the ozone reaction tank obtained as described above is left in the treated water of the ozone reaction tank by adding hydrogen peroxide and injecting ozone discharged from the ozone reaction tank in a UV reaction tank for irradiating ultraviolet rays. Endocrine disruptors or carcinogens can be decomposed and removed. In particular, the water to be treated
Since organic substances and chromaticity components were removed in the ozone reaction tank, the transmittance of ultraviolet rays in the UV reaction tank was increased, and OH caused by ultraviolet irradiation during injection of ozone and hydrogen peroxide.
While radical generation increases, even if there is residual ozone that did not contribute to the decomposition due to factors such as insufficient hydrogen peroxide in the ozone reaction tank, the efficiency of the UV reaction tank is improved by the coexistence of hydrogen peroxide and ultraviolet light. It dissolves well and can decompose and remove endocrine disrupting substances or carcinogenic substances that are targets.

Further, by returning the treated water of the UV reaction tank to the UV reaction tank again by the circulation pump, the UV
The reaction in the reaction tank is made uniform, and the UV irradiation effect is increased in the coexistence with ozone and hydrogen peroxide, so that the decomposition efficiency of the UV reaction tank can be improved. In addition, when an organic chlorine compound such as dioxins is to be treated, the high chlorinated organic compound is reduced in chlorine by UV irradiation, and the low chlorinated organic compound is completely decomposed by injection of ozone and hydrogen peroxide. As a result, the decomposition efficiency for the water to be treated increases.

[Brief description of the drawings]

FIG. 1 is a flow sheet of one embodiment of a method for treating organic wastewater of the present invention.

[Explanation of symbols]

1: Injection pipe for treated water 2: Ejector injection pipe 3: Ejector injection pump 4: Ozone reaction tank 5: H ₂ O ₂ injection pipe 6: Ejector 7: O ₃ gas 8: Waste ozone pressure regulating valve 9: Treated water outlet pressure Regulating valve 10: Waste ozone 11: Ozone reaction tank treated water 12: UV reaction tank 13: Ejector 14: UV lamp 15: H ₂ O ₂ injection pipe 16: Waste ozone 17: UV reaction tank circulation pump 18: Treated water 19: Ozone generator

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C02F 9/00 502 C02F 9/00 502R 503 503C 504 504B 504E (72) Inventor Sota Nakagawa Fujisawa Ichimoto, Kanagawa 4-2-1 Fujisawa F-term in Ebara Research Institute, Ltd. (Reference) 4D037 AA11 AB02 AB11 AB16 BA18 BB01 CA11 CA12 4D038 AA08 AB08 AB09 AB10 AB14 BA02 BA04 BA06 BB07 BB16 4D050 AA12 AA13 AB12 AB13 AB19 BB02 BB09 BC09 BD04 BD06 BD08 CA07

Claims (5)

[Claims] 1. A method for treating an organic wastewater containing an endocrine disrupting substance or a carcinogen, wherein ozone is injected into the water to be treated by an ejector method, hydrogen peroxide is added, and the water is introduced into an ozone reaction tank. To react in the ozone reaction tank, and then introduce and react the treated water in the ozone reaction tank into the ultraviolet irradiation reaction tank, and partially remove the treated ozone from the ozone reaction tank using the ejector method. A method for treating organic wastewater, wherein the organic wastewater is returned to an ultraviolet irradiation reaction tank while hydrogen peroxide is added and added. 2. The organic wastewater according to claim 1, wherein a pressure regulating valve is provided in a pipe of an exhaust ozone gas outlet and a treated water outlet of the ozone reaction tank so that the pressure in the ozone reaction tank can be adjusted to be high. Processing method. 3. The method for treating organic wastewater according to claim 1, wherein the endocrine disrupting substance or carcinogen is dioxin, bisphenol A, dioxane, or di (2-ethylhexyl) phthalate. 4. An organic wastewater treatment apparatus containing an endocrine disrupting substance or a carcinogen, comprising an ozone inhaler connected to an ozone generator and connected to a hydrogen peroxide supply pipe. A treated water inflow pipe having a tip inserted into the ozone reaction vessel, an ozone reaction vessel treated water outflow pipe and an ozone exhaust pipe at an upper part, and an ozone reaction vessel treated water circulation pipe communicating with the treated water inflow pipe at a lower part. The ozone reaction tank, an ultraviolet lamp suspended from the top, an ozone reaction tank treated water outlet pipe, an ultraviolet reactor treated water outlet pipe and an ozone discharge pipe at the top, and a lower part connected to the ozone discharge pipe of the ozone reaction tank at the middle. And an ultraviolet reactor ejector connected to a hydrogen peroxide injection pipe for the ultraviolet reactor, which is branched from the water outlet pipe of the ultraviolet reactor treated water, and an ultraviolet ray counter having a tip inserted into the ultraviolet reactor. An organic wastewater treatment apparatus, comprising: an ultraviolet irradiation reaction tank having a piping for circulating treated water. 5. The organic wastewater treatment apparatus according to claim 4, wherein a pressure regulating valve is provided in a pipe of an exhaust ozone gas outlet and a treated water outlet of the ozone reaction tank.