JP2012005918A - Method and device for treating wastewater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for treating wastewater capable of surely and inexpensively recovering recovery water low in residual TOC concentration, in treatment of wastewater containing an organic chemical constituent.SOLUTION: These method and device for treating wastewater execute: a biotreatment step of subjecting organic wastewater containing organic chemicals to degradative treatment by microorganisms; a biological activated carbon treatment step of treating the treated water treated in the biotreatment step by microorganisms supported to activated carbon; and an oxidative decomposition step of physicochemically subjecting the treated water treated in the biological activated carbon treatment step to oxidative decomposition treatment.

Description

  The present invention relates to a wastewater treatment method and a wastewater treatment apparatus for treating wastewater discharged from a production process, and in particular, discharged from a factory for manufacturing various electronic industrial products such as flat panel displays such as semiconductor devices and liquid crystal displays. The present invention relates to a wastewater treatment method and a wastewater treatment apparatus containing organic chemicals.

  In manufacturing plants for electronic components such as semiconductor devices and flat panel displays, IPA (isopropyl alcohol), methanol, acetone, TMAH (tetramethylammonium hydroxide), DMSO (dimethyl sulfoxide), phenol, acetic acid, Various organic chemicals such as surfactants are used.

  Various wastewater treatment methods have been studied in order to remove organic substances from wastewater containing organic chemicals discharged from manufacturing factories of electronic industrial products as described above and reuse them as washing water. .

  As a method for treating such waste water, for example, a biological treatment method for decomposing organic matter in waste water with activated sludge is known (Patent Document 1).

In this wastewater treatment, organic substances in wastewater are decomposed by aerobic organisms through biochemical reactions, and as a post-treatment after biological treatment, abiotic decomposition treatment such as treatment by ultraviolet irradiation or ozone addition (physical treatment) Chemical oxidative decomposition treatment) is performed.
This organic substance decomposition treatment by ultraviolet irradiation or ozone addition is an oxidative decomposition of organic substances in wastewater by reacting ultraviolet rays or ozone with wastewater by using an ultraviolet lamp or ozone generator. Organic components such as microbial metabolites can also be effectively decomposed.

  The oxidative decomposition process is a relatively expensive process because it requires means such as an ultraviolet lamp and an ozone generator as described above and requires a large amount of energy. However, when a biological treatment device is provided on the upstream side as described above, many organic chemicals can be decomposed by the biological treatment device, so that organic matter remaining after the treatment, metabolites generated by biological treatment, etc. A small amount of organic matter may be oxidized and decomposed with ultraviolet rays or ozone, and there is an advantage that recovered water having a low residual TOC concentration can be obtained at low cost.

However, wastewater discharged from factories may change the state of wastewater due to changes in processing in each manufacturing process. In other words, chemicals that are highly harmful to microorganisms may be mixed in the wastewater, or the wastewater may become low or high temperature that lowers the activity of the organism, and such wastewater is introduced into the biological treatment equipment. Then, the activity of the microorganisms in the biological treatment apparatus decreases, and the treatment capacity of the biological treatment apparatus may decrease until the activity is restored again.
As described above, when the treatment capacity of the biological treatment apparatus decreases, the oxidative decomposition treatment is performed by ultraviolet irradiation or the like while the residual TOC concentration is high, and high energy is required for the oxidative decomposition treatment. As a result, the entire process becomes expensive.

JP 2007-69204 A

  In view of the above-described conventional problems, the present invention provides a wastewater treatment method and a wastewater treatment apparatus capable of recovering recovered water having a low residual TOC concentration stably at low cost in the treatment of wastewater containing a chemical component. Is an issue.

  The present invention relating to a wastewater treatment method includes a biological treatment process in which organic wastewater containing organic chemicals is decomposed by microorganisms, and a biological treatment in which treated water treated in the biological treatment process is treated by microorganisms supported on activated carbon. An activated carbon treatment step and an oxidative decomposition step of physicochemically oxidizing and treating the treated water treated in the biological activated carbon treatment step are characterized.

  The biological treatment process referred to in the present invention includes known biological treatments such as activated sludge treatment, fluidized bed biological treatment, fixed bed biological treatment, and membrane separation activated sludge treatment.

  Furthermore, this invention which concerns on a wastewater treatment method does not perform the process in the said biological treatment process of the low concentration organic wastewater containing an organic chemical | medical agent in low concentration among the organic wastewater containing the said organic chemical | medical agent. It is preferable to treat in the biological activated carbon treatment step.

  Further, it is preferable that the oxidative decomposition step is oxidative decomposition by ultraviolet irradiation and / or ozone.

  Further, the present invention related to a wastewater treatment apparatus includes a biological treatment apparatus that decomposes organic wastewater containing organic chemicals with microorganisms, and a packed bed filled with activated carbon supporting microorganisms, A biological activated carbon treatment device that treats the treated water treated by the biological treatment device by passing it through, and an oxidative decomposition device that physicochemically oxidatively decomposes the treated water treated by the biological activated carbon treatment device It is characterized by.

  In the treatment method of the present invention, when the wastewater containing organic chemicals is treated in a biological treatment process and then subjected to physicochemical oxidative decomposition to decompose the organic chemicals in the wastewater, before the oxidative decomposition, Since the treatment by the biological activated carbon treatment process is carried out, even if the treatment capacity in the biological treatment process is reduced, the wastewater is discharged in the biological activated carbon treatment process capable of decomposing organic matter at a low cost before being introduced into the oxidative decomposition process. Since the organic matter inside is decomposed, wastewater treatment can be carried out with the energy in the oxidative decomposition process kept low. Therefore, even when the treatment capacity of the biological treatment process is reduced, the energy cost of waste water treatment can be reduced.

  Further, among the organic wastewater containing the organic chemicals, when introducing the low-concentration organic wastewater containing the organic chemicals at a low concentration into the biological activated carbon treatment step without going through the biological treatment step. The load of the biological treatment process can be reduced by reducing the amount of waste water to be treated in the biological treatment process.

  In addition, the waste_water | drain containing the organic chemical | medical agent of a low concentration here means the waste_water | drain whose TOC contained in waste_water | drain is less than about 10 mg.

  Further, the wastewater of the present invention may be the wastewater itself discharged from each production process such as a production factory, or the wastewater discharged from the production process is subjected to some treatment to be adjusted to the respective concentrations. It may be drainage.

1 is a schematic flow diagram showing a wastewater treatment apparatus and method of the present invention. The schematic flowchart which shows the waste water treatment method of an Example. The schematic flowchart which shows the waste water treatment method of an Example. The schematic flowchart which shows the waste water treatment method of a comparative example. The schematic flowchart which shows the waste water treatment method of a comparative example.

Hereinafter, the waste water treatment apparatus and waste water treatment method of the first embodiment of the present invention will be described with reference to FIG.
First, the waste water treatment apparatus will be described.
FIG. 1 is a schematic flow diagram of the waste water treatment apparatus of the present embodiment.
The code | symbol 1 in a figure has shown the waste water treatment apparatus.
The wastewater treatment apparatus 1 of this embodiment includes a biological treatment apparatus 2 that performs a biological treatment process that is a decomposition process of organic matter by microorganisms, and a filtration treatment apparatus 3 and a reverse osmosis treatment apparatus that treat wastewater treated by the biological treatment apparatus 2. 4, a biological activated carbon treatment device 5 introduced through 4, and an ultraviolet treatment device 6 that introduces wastewater treated by the biological activated carbon treatment device 5 and performs physicochemical oxidative decomposition.

  The biological treatment apparatus 2 is connected to an introduction path 11 through which high-concentration organic wastewater containing a high concentration of organic chemicals out of wastewater discharged from the manufacturing process of semiconductor devices and flat panel displays is connected. Yes.

  The biological treatment apparatus 2 is a known biological treatment apparatus such as an activated sludge treatment apparatus, a fluidized bed biological treatment apparatus, a fixed bed biological treatment apparatus, or a membrane separation activated sludge treatment apparatus, and drains water into the biological treatment apparatus. By passing water, the organic matter in the wastewater is decomposed by the microorganisms. In addition, various microorganisms, such as an aerobic microorganism and an anaerobic microorganism, are mentioned as microorganisms, The microorganisms and apparatus to be used can be suitably selected with the component of the waste_water | drain containing a high concentration organic chemical | medical agent.

The filtration treatment device 3 provided on the downstream side of the biological treatment device 2 is provided with a microfiltration membrane or an ultrafiltration membrane in the device, and filters out microorganisms and the like that have been washed away from the biological treatment device 2 and is being drained. To remove these runaway products.
The reverse osmosis treatment device 4 includes a reverse osmosis membrane in the device, and the wastewater is separated into concentrated water and permeate by bringing the wastewater into pressure contact with the reverse osmosis membrane, and the permeate is separated from the biological activated carbon treatment device. 5 is introduced.
Concentrated water is recovered as recovered water after distillation, and solids (such as salts) remaining by distillation are discarded separately. The concentrated water may be discharged from the system after drainage treatment.

  The biological activated carbon treatment apparatus 5 includes a packed bed filled with granular activated carbon supporting microorganisms that decompose organic substances such as aerobic microorganisms, introduces drainage into the packed bed, and removes organic matter in the drainage in the packed bed. Degraded by microorganisms.

  The biological activated carbon treatment apparatus 5 is provided with an introduction path 14 for introducing permeated water from the reverse osmosis treatment apparatus 4, and the introduction path 14 has a low concentration containing an organic chemical in the drainage at a low concentration. An introduction path 12 through which organic waste water is introduced is connected.

  The ultraviolet treatment apparatus 6 includes an ultraviolet lamp as means for irradiating ultraviolet rays, and irradiates the wastewater treated by the biological activated carbon treatment apparatus 5 with ultraviolet rays to oxidize and decompose organic substances in the wastewater. In addition, when supplying waste_water | drain to a ultraviolet-ray processing apparatus, it is preferable to add oxidizing agents, such as hydrogen peroxide, to waste_water | drain.

As the ultraviolet treatment apparatus 6, a known ultraviolet oxidative decomposition apparatus equipped with an ultraviolet lamp can be used. For example, a high-pressure ultraviolet oxidation apparatus that inserts a high-pressure ultraviolet lamp into a reaction tank storing wastewater to irradiate the wastewater with ultraviolet light, A low-pressure ultraviolet oxidizer that irradiates ultraviolet rays while allowing wastewater to pass through a reaction cylinder equipped with a low-pressure ultraviolet lamp can be used.
A well-known ultraviolet lamp can be used, but one having a wavelength of 185 to 365 nm, preferably 185 to 254 nm is suitable.

Furthermore, the wastewater treatment apparatus 1 of the present embodiment includes an ion removal treatment device 8 for treating wastewater containing inorganic chemicals among the wastewater, and the wastewater treated by the ion removal treatment device 8 is treated as the biological activated carbon. In order to introduce into the processing apparatus 5, an introduction path 13 is connected to the introduction path 14 from the reverse osmosis treatment apparatus 4.
The ion removal treatment device 8 includes a packed tower filled with an ion exchange resin. By passing waste water through the packed tower, the ion exchange resin and waste water come into contact with each other, and ions in the waste water are ion exchanged. It is adsorbed by the resin and removed.

  The wastewater treatment apparatus 1 according to the present embodiment includes a recovery tank 7 that recovers wastewater treated by the ultraviolet treatment apparatus 6 as recovered water.

Next, a wastewater treatment method for treating wastewater discharged from the manufacturing process of the semiconductor device or the platform display in the wastewater treatment apparatus of the present embodiment will be described.
First, the case where the biological treatment apparatus 2 maintains the normal processing capability will be described.

  Wastewater is collected for each process of the manufacturing process. Normally, the type of chemicals used in each manufacturing process is fixed, so the wastewater contains high concentrations of organic wastewater containing organic chemicals or low concentrations of organic chemicals depending on the process in which wastewater is collected. Whether it is low-concentration organic wastewater or inorganic wastewater containing inorganic chemicals is determined by processing in the manufacturing process.

The criteria for determining wastewater at this time can be set as appropriate. For example, wastewater whose TOC is less than 10 mg / L is determined as low-concentration organic wastewater.
Waste water containing high-concentration organic chemicals means waste water whose TOC contained in the waste water is about 10 mg / L or more.
In addition, in the waste water treatment equipment of this embodiment, it is possible to treat high concentration organic waste water having a TOC of about 1000 mg / L.
In addition, a trace amount of organic substance having a TOC concentration of less than 10 mg / L may be mixed in the inorganic waste water.

Among the wastewater, high-concentration organic wastewater is introduced into the biological treatment apparatus 2 through the introduction path 11, and a biological treatment process is performed in which organic matter in the wastewater is decomposed by microorganisms.
From the wastewater treated by the biological treatment apparatus 2, microorganisms and the like that have been washed away from the biological treatment apparatus 2 are removed by the filtration treatment apparatus 3.
Further, the waste water is separated into concentrated water and permeate by the reverse osmosis treatment device 4, and the permeate is introduced into the biological activated carbon treatment device 5.

  When the microorganisms in the biological treatment apparatus 2 maintain normal activity, that is, when the treatment capacity of the biological treatment apparatus is normal, high-concentration organic waste water containing about 120 mg / L of TOC. The TOC concentration in the wastewater is reduced to about 5 to 8 mg / L by passing through the biological treatment device 2.

  On the other hand, among the wastewater, low-concentration organic wastewater, that is, wastewater containing a small amount of organic matter having a TOC concentration of less than 10 mg / L, passes through the introduction path 12 without passing through the biological treatment device 2. It is introduced into the introduction path 14 connected to the activated carbon treatment device 5.

Further, the inorganic waste water is introduced into the ion removal treatment device 8 and ions in the waste water are removed, and then introduced into the introduction passage 14 through the introduction passage 13.
Usually, the TOC of the inorganic waste water after the treatment in the ion removal treatment device 8 is less than 5 mg / L.

As described above, the high-concentration organic wastewater, the low-concentration organic wastewater and the ion-removed inorganic wastewater treated by the biological treatment apparatus 2 are mixed in the introduction path 14 and are directed downward to the biological activated carbon treatment apparatus 5 from above. The water is passed in a stream.
As described above, low concentration organic wastewater and inorganic wastewater with low TOC concentration are introduced into the biological activated carbon treatment device 5 without passing through the biological treatment process in the biological treatment device 2. A processing amount can be reduced and the load on the biological treatment apparatus 2 can be reduced.

In the biological activated carbon treatment apparatus 5, a biological activated carbon treatment process is performed in which organic matter in the wastewater is decomposed by microorganisms supported on the activated carbon, and the wastewater is discharged as treated water from below the apparatus.
The TOC concentration of the wastewater treated by the biological activated carbon treatment device 5 is usually about 1 mg / L or less.

In this way, wastewater is introduced into the ultraviolet treatment device 6 in a state where the TOC concentration is reduced to about 1 mg / L or less.
An oxidative decomposition process is performed in which the wastewater introduced into the ultraviolet treatment device 6 is irradiated with ultraviolet rays, and the organic matter in the wastewater is physicochemically oxidized and decomposed. At this time, it is preferable to perform the treatment with the power consumption of the ultraviolet lamp being 1.1 kWh / m ³ and the treatment time being about 20 minutes.

  As described above, since the TOC concentration of the wastewater is low at the time when it is introduced into the ultraviolet treatment device 6, the organic matter in the wastewater can be decomposed while the power consumption of the ultraviolet rays is low.

Next, the case where the processing capacity of the biological treatment apparatus 2 of the waste water treatment apparatus 1 of the present embodiment is lower than usual will be described.
For example, depending on the state of the manufacturing process of the semiconductor device, flat panel display, etc., the discharged waste water may be mixed with chemicals that are highly harmful to microorganisms, or low or high temperature that lowers the activity of living organisms. In some cases, temperature wastewater is introduced into the wastewater treatment apparatus 1.

In such a case, the microorganisms in the biological treatment apparatus 2 are killed or the activity is lowered, so that the treatment capability of the biological treatment apparatus 2 is lowered.
For example, normally, the TOC concentration can be lowered to about 5 mg / L by the biological treatment apparatus 2 for high-concentration organic wastewater containing about 120 mg / L of TOC. In some cases, for example, the TOC concentration can be reduced only to about 10 to 12 mg / L.

  Even in such a case, since the wastewater treatment apparatus 1 of the present embodiment treats with the biological activated carbon treatment apparatus 5 as described above and then treats with the ultraviolet treatment apparatus 6, power consumption in the ultraviolet treatment apparatus 6 is greatly increased. Even if it is not increased, recovered water having a sufficiently low TOC concentration can be obtained, and wastewater treatment can always be performed stably and at low cost.

In this embodiment, the high concentration organic wastewater and the low concentration organic wastewater are introduced into one biological activated carbon treatment apparatus and treated. For example, the high concentration organic wastewater and the low concentration organic wastewater are respectively treated. You may process with another biological activated carbon processing apparatus.
However, the structure of the waste water treatment apparatus 1 can be simplified by performing the treatment with one biological activated carbon treatment apparatus as in the present embodiment.

In this embodiment, an ultraviolet treatment device is used as a physicochemical oxidative decomposition means. However, as an oxidative decomposition means, an oxidative decomposition apparatus equipped with an ozone generator or other physicochemical decomposition can be used. Oxidative decomposition means may be used.
Furthermore, oxidative decomposition may be performed by combining a plurality of different oxidative decomposition means.

  Furthermore, in this embodiment, an ion removal treatment apparatus is provided to treat inorganic wastewater. However, provision of such an ion removal treatment apparatus is not a condition. For example, low concentration organic wastewater and inorganic wastewater are combined. You may process as a low concentration organic waste water.

  In the present embodiment, the case where the wastewater discharged from the manufacturing process of the semiconductor device or the flat panel display is collected for each process and directly introduced into each treatment process has been described. After adjusting to a density, processing may be performed by the processing method or processing apparatus of the present invention.

  Furthermore, in the present embodiment, a filtration processing apparatus equipped with a microfiltration membrane was used as the filtration processing apparatus, but the filtration processing apparatus was selected from other known filtration means such as ultrafiltration membranes and coagulation filtration. it can.

  In this embodiment, a reverse osmosis treatment apparatus is provided and the waste water is separated into concentrated water and permeate. However, it is not essential to provide such a reverse osmosis treatment apparatus.

  EXAMPLES Next, although an Example is given and this invention is demonstrated in more detail, this invention is not limited to these.

Example 1
As Example 1, waste water treatment equipment similar to that of the above embodiment was used, and waste water treatment in a normal case was performed with a treatment flow as shown in FIG.
That is, first, in the biological treatment apparatus (product name BCF manufactured by Shinko Environmental Solution Co., Ltd., Biocontact Filter: fixed bed type biological treatment apparatus using a ceramic carrier, processing capacity 180 m ³ / d), the TOC concentration is about 120 mg / L. The biological treatment process was implemented by introducing high concentration organic wastewater.
The TOC concentration of the treated water of the biological treatment apparatus at this time was about 5.2 mg / L.
RO treatment water (TOC 1.1 mg / L) of high-concentration organic wastewater was sequentially introduced into a filtration treatment device (using a device using an MF membrane in this example) and a reverse osmosis treatment device (RO device). .

The waste water is waste water from the liquid crystal display manufacturing process, and is mainly waste water containing DMSO (dimethyl sulfoxide), TMAH (tetramethyl ammonium hydroxide), IPA (isopropyl alcohol), and the like.
Since the components and concentration in the wastewater differ depending on the treatment performed in each manufacturing process, the wastewater is collected for each process, and as shown in the above embodiment, as high-concentration organic wastewater, low-concentration organic wastewater, and inorganic wastewater. Sorted.

  On the other hand, inorganic wastewater having a TOC concentration of about 2.8 mg / L was treated with an ion removal treatment apparatus (in this example, an ion exchange apparatus, manufactured by Shinko Environmental Solution Co., Ltd.). The TOC concentration after the treatment with the ion removal treatment apparatus was about 2.3 mg / L.

The RO-treated water, the treated water of the ion removal treatment device, and the low-concentration organic waste water having a TOC concentration of about 3.5 mg / L are mixed at 300 L / h, respectively, and biological at a treatment amount of 900 L / h. Biological activated carbon treatment process was carried out with activated carbon treatment equipment.
At this time, the TOC concentration of the mixed water was about 2.3 mg / L.

As the biological activated carbon treatment apparatus, a fixed bed downward flow type Bio-AC column (500 mmφ × 3.8 mH) and activated carbon (430 L, particle size 1.3 to 1.6 mm spherical activated carbon) were used, and HRT = 28.7. Min., And processing was performed under the processing conditions of 900 L / h.
The power consumption per unit volume of waste water in the biological activated carbon treatment was 0.2 kWh / m ³ . The TOC concentration of the treated water after this biological activated carbon treatment was about 0.49 mg / L.

Further, the treated water was introduced into the oxidative decomposition apparatus. As the oxidative decomposition apparatus, the RO treatment is carried out at 900 L / h by HRT (hydraulic residence time) 20 minutes using an ultraviolet oxidative decomposition apparatus of 300 L in an oxidation tank using a 1 kW high-pressure ultraviolet lamp (manufactured by Toshiba Lighting & Technology). Oxidative decomposition treatment of water was performed.
In addition, before introducing into the ultraviolet oxidative decomposition apparatus, 4 times the amount of oxygen consumption hydrogen peroxide was added.
The ultraviolet irradiation power per unit volume of waste water in the ultraviolet oxidative decomposition treatment was 1.1 kWh / m ³ .
Thereafter, the TOC concentration of the collected recovered water was reduced to about 0.15 mg / L.

(Example 2)
As Example 2, the case where the processing capability of the biological treatment apparatus of the apparatus of Example 1 is reduced as shown in the flow of FIG. 3 will be described.
That is, the TOC concentration of treated water after treatment with the biological treatment apparatus was about 10.1 mg / L. Thereafter, in the same manner as in the above example, the RO treated water obtained by sequentially introducing it into the filtration device and the reverse osmosis treatment device (RO device), the low-concentration organic waste water, and the inorganic waste water after the ion removal are the same as in Example 1. The treatment was performed with a biological activated carbon treatment apparatus.
The power consumption per unit volume of waste water in the biological activated carbon treatment was 0.2 kWh / m ³ . The TOC concentration of the treated water after this biological activated carbon treatment was about 0.76 mg / L.

Further, the treated water treated with this biological activated carbon treatment apparatus was treated with an ultraviolet oxidative decomposition apparatus in the same manner as in Example 1.
The ultraviolet irradiation power per unit volume of waste water in the ultraviolet oxidative decomposition treatment at this time is 1.7 kWh / m ³ , and the TOC concentration of the collected recovered water is about 0.15 mg / L, which is the same level as in the first embodiment. Met.

(Comparative Example 1)
Next, as Comparative Example 1, except that there is no biological activated carbon treatment device, the waste water treatment device having the same configuration as in Example 1 and the waste water treatment performed in the same manner as in Example 1 are shown in FIG. Processed as shown.
That is, high-concentration organic wastewater was sequentially introduced into a biological treatment device, a filtration treatment device, and a reverse osmosis treatment device in the same manner as in the above-described example, to obtain RO-treated water of high-concentration organic wastewater.
At this time, the TOC concentration of the treated water after the biological treatment was about 1.1 mg / L.
On the other hand, inorganic wastewater (TOC concentration 2.3 mg / L) and low-concentration organic wastewater (TOC concentration 3.5 mg / L) subjected to the same ion removal treatment as in the above examples were combined with the RO-treated water. Each was mixed at 100 L / h, and introduced into an ultraviolet oxidative decomposition apparatus similar to Example 1 at a treatment amount of 300 L / h.
In addition, hydrogen peroxide 4 times the amount of oxygen consumption was added before introduce | transducing to an ultraviolet-ray processing apparatus.
The ultraviolet irradiation power per unit volume of waste water in the oxidative decomposition treatment with ultraviolet rays was 3.3 kWh / m ³ .
Thereafter, the TOC concentration of the collected recovered water was about 0.25 mg / L.

(Comparative Example 2)
Next, as a comparative example 2, a wastewater treatment apparatus having the same configuration as that of the comparative example 1, and a case where the treatment capacity of the biological treatment apparatus is reduced as in the case of the above-described example 2 is as shown in the flow shown in FIG. Processed.
That is, the TOC concentration of treated water after treatment with the biological treatment apparatus was about 10.1 mg / L. Thereafter, in the same manner as in the above example, RO treated water obtained by sequentially introducing into a filtration device and a reverse osmosis treatment device (RO device), low-concentration organic waste water, and inorganic waste water after ion removal are the same as in Comparative Example 1. It processed with the ultraviolet oxidation decomposition device.
The ultraviolet irradiation power per unit volume of waste water in the ultraviolet oxidative decomposition treatment at this time was 5.5 kWh / m ³ , and the TOC concentration of the collected recovered water was about 0.25 mg / L.

  From the above, the examples were able to obtain recovered water with low power consumption and low TOC concentration in either case, even when the biological treatment apparatus had a normal treatment capacity or when the ability decreased.

1: Waste water treatment equipment,
2: biological treatment equipment,
3: Filtration processing device,
4: Reverse osmosis treatment device,
5: Biological activated carbon treatment device,
6: UV treatment device,
7: Collection tank

Claims (6)

  A biological treatment process for decomposing organic wastewater containing organic chemicals by microorganisms, a biological activated carbon treatment process for treating treated water treated in the biological treatment process by microorganisms supported on activated carbon, and the biological activated carbon treatment A wastewater treatment method characterized by performing an oxidative decomposition step of physicochemically oxidizing and treating the treated water treated in the step.   The low-concentration organic waste water containing the organic chemical at a low concentration among the organic waste water containing the organic chemical is treated in the biological activated carbon treatment step without being treated in the biological treatment step. The waste water treatment method according to 1.   The wastewater treatment method according to claim 1 or 2, wherein the oxidative decomposition step performs oxidative decomposition by ultraviolet irradiation and / or ozone. A biological treatment device that decomposes organic wastewater containing organic chemicals with microorganisms;
A biological activated carbon treatment apparatus comprising a packed bed filled with activated carbon carrying microorganisms, and treating the packed bed by passing treated water treated by the biological treatment apparatus;
A wastewater treatment apparatus comprising: an oxidative decomposition apparatus that physicochemically oxidatively decomposes treated water treated by the biological activated carbon treatment apparatus.   2. An introduction path for introducing low concentration organic wastewater containing an organic chemical at a low concentration out of the organic wastewater containing the organic chemical into the biological activated carbon treatment device without passing through the biological treatment device. 4. The waste water treatment apparatus according to 4.   The waste water treatment apparatus according to claim 4 or 5, wherein the oxidative decomposition apparatus is an ultraviolet irradiation apparatus and / or an ozone treatment apparatus.

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