JP5782229B2 - Wastewater treatment method - Google Patents

Description

The present invention relates to a waste water treatment how to handle the waste water discharged from the production process, in particular, for example, waste water treatment direction discharged from manufacturing plants of various electronic industrial products such as flat panel displays, such as semiconductor devices and liquid crystal it relates to the law.

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 chemicals such as organic chemicals such as surfactants and inorganic chemicals are used.
In these manufacturing processes, since different chemicals are used for each process of the manufacturing processes, the components of the chemicals contained in the waste water discharged from each process are also different.

  In addition, since cleaning with pure water is performed after chemical treatment in each process, cleaning water containing the cleaned chemical is also discharged as waste water. This drainage of washing water contains high-concentration chemicals in the initial washing immediately after the chemical treatment process, but when washing is repeated many times, Very low concentration.

  Therefore, the wastewater discharged from the manufacturing process is discharged with different components and concentrations depending on the discharged process.

Various wastewater treatment methods have been studied in order to treat wastewater discharged from a manufacturing factory for electronic industrial products as described above and reuse it as washing water or the like.
The wastewater containing inorganic chemicals is usually subjected to a process of adsorbing and removing ions by an ion exchange process or the like (Non-Patent Document 1).

  Examples of a method for treating wastewater containing organic chemicals include a biological treatment method (Non-Patent Document 1) that decomposes organic matter in wastewater by biological treatment, and a method that oxidizes and decomposes by irradiating ultraviolet rays, ozone, and the like. Known (Patent Document 1).

The biological treatment described in Non-Patent Document 1 is a method in which organic matter in wastewater is decomposed by an aerobic organism by a biochemical reaction and recovered as recovered water by filtration, and has an advantage that wastewater treatment can be performed economically. is there.
On the other hand, when the organic matter concentration in the wastewater is high, for example, when treating wastewater containing a high concentration organic chemical in which the total organic carbon (hereinafter referred to as TOC) concentration in the wastewater is several tens mg / L, In biological treatment methods (active sludge, fluidized bed, fixed bed, membrane separation activated sludge method) suitable for wastewater treatment containing high concentrations of organic matter, biological metabolites are generated, so all organic matter in the wastewater is decomposed. However, an organic substance as a biological metabolite of several mg / L remains in the waste water.

  Since the wastewater after the biological treatment has already been decomposed by microorganisms, the organic matter as a biological metabolite is treated, so that there is a problem that the organic matter cannot be effectively decomposed even if the biological treatment is repeated. It was.

Therefore, as described in Patent Document 1, abiotic decomposition treatment (physicochemical oxidative decomposition treatment) such as treatment by ultraviolet irradiation or ozone addition is performed as post-treatment after biological treatment.
Decomposition treatment by ultraviolet irradiation or ozone addition is an oxidative decomposition of organic matter in wastewater by generating ultraviolet rays or ozone from an ultraviolet lamp or ozone generator and reacting with wastewater. Residual TOC after biological treatment is also effective Can be decomposed.

  However, such physicochemical oxidative decomposition treatment requires a means for oxidative decomposition such as an ultraviolet lamp and an ozone generator as described above, requires a large amount of energy, and is more expensive than the biological treatment. It is. Therefore, when the amount of wastewater to be treated by oxidative decomposition increases, there is a problem that the cost of the whole wastewater treatment increases.

Shinko Pantech Co., Ltd., Shinko Pantech Technical Report Vol. 39 no. 2, p. 49-55 (1996/3)

JP 2007-69204 A

The view of the conventional problems, the present invention provides a process of wastewater containing chemicals components, and to provide a wastewater treatment how that can economically recover low recovery water residual TOC concentration.

  The present invention relating to the wastewater treatment method introduces wastewater containing high concentration organic chemicals into wastewater treatment line, introducing wastewater containing high concentration organic chemicals into high concentration wastewater treatment line. Introduced into the low-concentration wastewater treatment line, in the high-concentration wastewater treatment line, a biological treatment process for treating organic matter in the wastewater with microorganisms and a physicochemical oxidative decomposition process are carried out. A biological treatment process for treating wastewater, which is biologically treated water, with microorganisms is performed.

  Furthermore, the present invention relating to the wastewater treatment method is to measure the organic matter concentration in the wastewater before the biological treatment step in the low-concentration wastewater treatment line, and when the organic matter concentration is higher than a predetermined concentration. It is preferable to introduce at least a part of the waste water into the physicochemical oxidative decomposition process of the high-concentration waste water treatment line.

Furthermore, this invention which concerns on a wastewater treatment method introduce | transduces the waste_water | drain containing an inorganic type chemical | medical agent into an inorganic-type wastewater treatment line among the wastewater discharged | emitted from the said manufacturing process, In this inorganic-type wastewater treatment line, It removes ions.

Further, the present invention according to the waste water treatment method that processes the processed by the ion removal process wastewater in the biological treatment process of the low-concentration waste water treatment line.

  Further, according to the present invention relating to the wastewater treatment method, in the high-concentration wastewater treatment line, a reverse osmosis membrane treatment step is performed in which the wastewater is permeated with a reverse osmosis membrane, and the wastewater treated in the reverse osmosis membrane treatment step is treated. It is preferable to treat in the physicochemical oxidative decomposition step.

  In the present invention relating to the wastewater treatment method, the physicochemical oxidative decomposition step is preferably oxidatively decomposed by ultraviolet rays or ozone.

  In addition, the abiotic treated water as used in the field of this invention means the water which has not performed the biological treatment for decomposing | disassembling the organic substance in wastewater with microorganisms.

In addition, wastewater treatment equipment introduces wastewater containing high-concentration organic chemicals into high-concentration wastewater treatment lines out of wastewater containing organic chemicals discharged from the manufacturing process. A wastewater treatment apparatus having an introduction means for introducing wastewater contained therein into a low-concentration wastewater treatment line, the high-concentration wastewater treatment line comprising biological treatment means for treating wastewater with microorganisms, and physicochemical oxidative decomposition means And the low-concentration wastewater treatment line is characterized by comprising a biological treatment device for treating the wastewater with a living organism.

Further, the wastewater treatment apparatus includes a low-concentration wastewater treatment line, a measurement device that measures the organic matter concentration in the wastewater before the wastewater is introduced into the biological treatment device, and the organic matter concentration measured by the measurement device is a predetermined value. It is preferable to provide a bypass line that introduces at least a part of the wastewater into the physicochemical oxidative decomposition means of the high-concentration wastewater treatment line when the concentration is higher.

In the treatment method of the present invention, waste water containing a high concentration organic chemical and waste water containing a low concentration organic chemical are introduced into separate treatment lines (a high concentration waste water treatment line and a low concentration waste water treatment line), respectively. Since wastewater treatment is performed, the amount of wastewater treated in the physicochemical oxidative decomposition process in the high concentration wastewater treatment line is reduced, and in the low concentration wastewater treatment line, the biological treatment process is more economical than physicochemical oxidative decomposition. Since the wastewater is treated in this way, the organic matter in the wastewater can be decomposed at a low energy and cost as a whole.
Furthermore, in the biological treatment process of the low-concentration wastewater treatment line, wastewater that is unbiologically treated water is treated, so that organic matter can be efficiently decomposed.
In addition, since a biological treatment process for performing wastewater treatment by living organisms is provided before the physicochemical oxidative decomposition process, in order to perform physicochemical oxidative decomposition after reducing the organic matter in the wastewater by performing biological treatment, Energy cost of physicochemical oxidative decomposition treatment can be reduced.

In addition, the waste water containing the high concentration organic chemical here refers to waste water having a TOC contained in the waste water of about 10 mg / L or more, preferably 30 mg / L or more.
Moreover, the wastewater containing a low concentration organic chemical means the wastewater whose TOC contained in wastewater 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.

  Further, the organic matter concentration in the wastewater is measured before performing the biological treatment process performed in the low-concentration wastewater treatment line, and when the organic matter concentration is higher than a predetermined concentration, at least a part of the wastewater is Because it is introduced into the physicochemical oxidative decomposition process of the concentration wastewater treatment line, even if high-concentration organic chemicals that cannot be treated in the biological treatment process are mixed into the low-concentration wastewater treatment line, stable organic substance decomposition processing can be performed. And recovered water having a low residual TOC concentration can be obtained.

  The wastewater treatment method of the present invention includes treatment in an inorganic wastewater treatment line for treating wastewater containing inorganic chemicals, and the inorganic wastewater treatment line includes an ion removal treatment step for removing ions in the wastewater. When implemented, wastewater containing inorganic chemicals can be treated in a separate treatment step from wastewater containing high-concentration organic chemicals, and therefore treated in the physicochemical oxidative decomposition step. Without increasing the amount of waste water, waste water containing inorganic chemicals can also be treated.

  In addition, when the wastewater treated in the ion removal treatment step is treated in the biological treatment step, the organic waste is contained in the wastewater containing inorganic chemicals as compared with the physicochemical oxidative decomposition. Can be removed by economical biological treatment.

  In the high-concentration wastewater treatment line, when wastewater is treated in the reverse osmosis membrane treatment process and then treated in the oxidative decomposition process, the amount of organic matter that undergoes oxidative decomposition is reduced, and energy in the oxidative decomposition process is further increased. Can be lowered.

  In the wastewater treatment method of the present invention, when ultraviolet rays or ozone is used as the physicochemical oxidative decomposition means, organic substances in the wastewater can be reliably decomposed.

1 is a schematic flow diagram showing a wastewater treatment apparatus and method of the present invention. 1 is a schematic flow diagram showing a wastewater treatment apparatus and method of the present invention. Schematic flowchart showing the wastewater treatment method of the example Schematic flow diagram showing the wastewater treatment method of the comparative example Schematic flow diagram showing the wastewater treatment method of the comparative example Graph showing the relationship between accumulated TOC amount flowing into biological activated carbon treatment equipment and differential pressure Graph showing the TOC concentration flowing into the biological activated carbon treatment equipment and the duration of treatment

<First embodiment>
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 high-concentration wastewater treatment line 10 into which wastewater containing high-concentration organic chemicals is introduced, and a low-concentration wastewater treatment into which wastewater containing low-concentration organic chemicals is introduced. Line 20.

  Furthermore, the wastewater treatment apparatus 1 of this embodiment includes an inorganic wastewater treatment line 30 for treating wastewater containing inorganic chemicals.

  The waste water treatment apparatus 1 includes an introduction line (not shown) for introducing waste water into each treatment line.

The high-concentration wastewater treatment line 10 includes an ultraviolet oxidative decomposition treatment apparatus 11 that performs oxidative decomposition by irradiating wastewater with ultraviolet rays as a physicochemical oxidative decomposition treatment apparatus.
Further, the high-concentration wastewater treatment line 10 includes a biological treatment device 12, a filtration treatment device 13 that filters wastewater treated by the biological treatment device 12, and reverses the wastewater before being introduced into the ultraviolet oxidative decomposition treatment device 11. And a reverse osmosis membrane processing apparatus 14 for processing with the osmosis membrane.

  The ultraviolet oxidative decomposition treatment apparatus 11 includes an ultraviolet lamp as a means for irradiating ultraviolet rays. The wastewater separated as permeate by the reverse osmosis membrane treatment apparatus is introduced into the treatment apparatus, and the wastewater is irradiated with ultraviolet rays. To oxidize and decompose organic matter in the wastewater. In addition, when supplying wastewater to an ultraviolet oxidative decomposition treatment apparatus, it is preferable to add an oxidizing agent such as hydrogen peroxide to the wastewater.

As the ultraviolet oxidative decomposition treatment apparatus 11, a known ultraviolet oxidative decomposition apparatus equipped with an ultraviolet lamp can be used. For example, an ultraviolet lamp is inserted into a drainage tank for storing wastewater to irradiate the wastewater in the storage tank with ultraviolet rays. The one which irradiates ultraviolet rays while inserting the ultraviolet lamp into the cylindrical drainage pipe and circulating the drainage through the drainage pipe 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.

  The biological treatment apparatus 12 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 13 provided in the latter stage of the biological treatment device 12 is provided with a microfiltration membrane or an ultrafiltration membrane in the device, and drains water by filtering microorganisms and the like washed away from the biological treatment device 12. Can be removed from inside.
The reverse osmosis membrane treatment device 14 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. Introduced into the processing apparatus 11.
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 low-concentration wastewater treatment line 20 is provided with a biological activated carbon treatment device 21 as a biological treatment device.
The biological activated carbon treatment device 21 includes a packed bed filled with granular activated carbon supporting microorganisms that decompose organic substances such as aerobic microorganisms, introduces waste water into the packed bed, and removes organic matter in the waste water in the packed bed. Degraded by microorganisms.

  The inorganic wastewater treatment line 30 includes an ion removal treatment device 31. The ion removal treatment device 31 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 treated by the ion removal treatment device 31 is introduced into the biological activated carbon treatment device 21 provided in the low concentration wastewater treatment line 20.

  The wastewater treatment apparatus 1 according to this embodiment includes a collection tank 15 that collects wastewater treated by the ultraviolet oxidative decomposition treatment apparatus 11 and the biological activated carbon treatment apparatus 21 as recovered water.

Next, the waste water treatment method implemented in the waste water treatment apparatus of this embodiment will be described.
As shown in FIG. 1, waste water discharged from a manufacturing process of a semiconductor device or a liquid crystal flat display is introduced into the waste water treatment apparatus 1.

  Wastewater is collected for each process of the manufacturing process. Usually, since the type of chemical used in each manufacturing process is determined, whether the wastewater contains a high concentration of organic chemicals or the wastewater contains a low concentration of organic chemicals, depending on the process in which the wastewater is collected, It is determined whether the wastewater contains inorganic chemicals, and wastewater is introduced into any one of the high-concentration wastewater treatment line 10, the low-concentration wastewater treatment line 20, or the inorganic wastewater treatment line 30.

As a judgment standard at this time, if the TOC contained in the wastewater is about 10 mg / L or more, it is judged as wastewater containing high concentration organic chemicals.
Moreover, the waste water whose TOC contained in waste water is less than 10 mg / L is judged as a low concentration organic chemical containing waste water.
The inorganic chemical-containing waste water may be mixed with a trace amount of organic matter having a TOC concentration of less than 10 mg / L.

The wastewater introduced into the high-concentration wastewater treatment line 10 is first decomposed by organic matter in the wastewater by the microorganisms in the biological treatment device 12. From the wastewater treated by the biological treatment device 12, microorganisms and the like that have been washed away from the biological treatment device 12 are removed by the filtration treatment device 13.
Further, the wastewater is separated into concentrated water and permeated water by the reverse osmosis membrane device 14, and the wastewater recovered as permeated water from which organic substances are further removed is introduced into the ultraviolet oxidative decomposition treatment device 11.
Since concentrated water contains organic substances, salts, and the like, the water may be recovered after further concentration and separation by distillation or reverse osmosis membrane filtration.

  As described above, wastewater containing organic chemicals with a high concentration containing TOC of about 10 mg / L or more has a TOC concentration in the wastewater of about 5 mg / L to about 10 mg / L through the biological treatment device 12. Moreover, it falls to about 1 mg / L by the process in the said filtration processing apparatus 13 and the reverse osmosis membrane apparatus 14, for example.

In this way, wastewater is introduced into the ultraviolet oxidative decomposition treatment apparatus 11 with the TOC concentration lowered to about 1 mg / L.
The wastewater introduced into the ultraviolet oxidative decomposition treatment apparatus 11 is irradiated with ultraviolet rays to oxidize and decompose organic substances in the wastewater. At this time, it is preferable to perform the treatment with the power consumption of the ultraviolet lamp 1.1 kWh / m ³ and the treatment time of about 20 minutes.

  As described above, since the TOC concentration of the wastewater is considerably lowered at the time when it is introduced into the ultraviolet oxidation treatment apparatus 11, the organic matter in the wastewater can be decomposed by irradiating with ultraviolet rays for a short time.

On the other hand, the wastewater introduced into the low-concentration wastewater treatment line 20 is treated water in which organic matter in the wastewater is decomposed by the microorganisms carried on the activated carbon by passing the wastewater downward from the biological activated carbon treatment device 21. It is recovered as recovered water from below the apparatus.
The TOC concentration of the wastewater treated by the biological activated carbon treatment device 21 is about 0.3 mg / L or less, and the TOC concentration is reduced to the extent that it can be recovered as recovered water.

Since low-concentration wastewater treatment line 20 is introduced with wastewater having a low TOC concentration, treatment with only the biological activated carbon treatment device 21 can be sufficiently performed within the normal treatment range.
Further, in the low concentration wastewater treatment line 20, the wastewater which is not pretreated before being treated with the biological activated carbon treatment 21, that is, the biologically treated water which has not undergone biological treatment is introduced into the biological activated carbon treatment apparatus 21. Therefore, the organic matter can be effectively decomposed by the biological treatment by the biological activated carbon treatment apparatus.

Further, the wastewater introduced into the inorganic wastewater treatment line 30 is introduced into the ion removal treatment device 31 to remove ions in the wastewater.
The wastewater from which ions have been removed by the ion removal treatment device 31 is introduced into the biological activated carbon treatment device 21 of the low-concentration wastewater treatment line 20.
By treating the waste water containing inorganic chemicals with the biological activated carbon treatment device 21 as described above, the organic matter can be reliably treated even when the organic matter is slightly contained.

As described above, only the wastewater containing organic chemicals at a high concentration out of all wastewater is subjected to ultraviolet oxidation treatment, so the amount of treatment with high operation cost for ultraviolet treatment is small, saving energy and being economical. It is.
Furthermore, since wastewater subjected to ultraviolet treatment is also subjected to biological treatment in advance, the concentration of organic matter in the wastewater is reduced, so that recovered water having a low TOC concentration can be obtained even with a small amount of ultraviolet irradiation.

On the other hand, wastewater containing organic chemicals at low concentrations and wastewater containing inorganic chemicals can be subjected to UV treatment with high operating costs by decomposing and removing organic substances using biological activated carbon, which is less expensive than ultraviolet irradiation. The amount of treatment to be performed can be reduced, and wastewater treatment can be performed at low cost with energy saving.
Furthermore, in the biological activated carbon treatment apparatus of the low concentration waste water treatment line, the organic matter in the waste water can be effectively decomposed in order to treat the non-biological treated water.

<Second embodiment>
Next, the waste water treatment apparatus and waste water treatment method of the second embodiment of the present invention will be described with reference to FIG.
The wastewater treatment apparatus 1 of this embodiment includes a high-concentration organic wastewater treatment line 10 and a low-concentration organic wastewater treatment line 20 having the same configuration as the wastewater treatment apparatus of the first embodiment.
An inorganic wastewater treatment line 30 is also provided in the same manner.

As shown in FIG. 2, a concentration measuring means 22 capable of measuring the TOC concentration of the wastewater is provided in the wastewater introduction pipe 21 a before introducing the wastewater into the biological activated carbon treatment device 21 of the low concentration organic wastewater treatment line 20.
The introduction pipe 21a for introducing the waste water into the biological activated carbon treatment apparatus 21 is provided with a valve 23 and a bypass line 40 connected to the introduction pipe for introduction into the ultraviolet oxidative decomposition treatment apparatus 11 of the high concentration waste water treatment line 10. It has been. The bypass line 40 is also provided with a valve 40a.

  In the wastewater treatment method in the wastewater treatment apparatus 1 of the present embodiment, first, wastewater collected in each step of the manufacturing process is treated as the high-concentration wastewater treatment line 10 and the low-concentration wastewater treatment line as in the first embodiment. 20 or the inorganic wastewater treatment line 30.

  Before the wastewater introduced into the low-concentration wastewater treatment line 20 is introduced into the biological activated carbon treatment device 21, the concentration measuring means 22 measures the TOC concentration in the wastewater.

When the measured TOC concentration exceeds the concentration that can be treated by the biological activated carbon treatment device 21, the valve 23 of the introduction pipe 21a is closed and the valve 40a of the bypass line 40 is opened simultaneously, It is introduced into the oxidative decomposition treatment apparatus 11 of the high-concentration wastewater treatment line 10 through the bypass line 40.
On the other hand, when the measured TOC concentration is a concentration that can be processed by the biological activated carbon treatment device 21, the valve 23 of the introduction pipe 21a is opened, and the valve 40a of the bypass line 40 is closed at the same time, It is introduced into the biological activated carbon treatment device 21 through the introduction tube 21a as usual.
The TOC concentration that can be processed by the biological activated carbon treatment device can be set to a predetermined concentration according to the treatment capacity of the biological activated carbon treatment device to be used.
The appropriate range of the predetermined concentration varies depending on the biological activated carbon treatment apparatus to be used. In a general apparatus, the upper limit is the frequency of backwashing once every 12 hours of water flow, and the range is set in the range of 5 mg / L to 10 mg / L. It is preferable to do.

  Normally, the wastewater discharged from the manufacturing process can be distinguished from the organic matter concentration in the wastewater by treatment, but for some reason, even if wastewater with a high organic matter concentration is mixed into the low-concentration wastewater treatment line, biological activated carbon treatment By measuring the TOC concentration before introducing it into the device 21, it is possible to prevent the biological activated carbon treatment device 21 from being loaded, and at the same time, it is possible to reliably obtain recovered water with a low TOC concentration.

Note that the amount of wastewater that is distributed from the low-concentration wastewater treatment line 20 to the high-concentration wastewater treatment line 10 via the bypass line 40 may be all or a part thereof to the bypass line 40, and the remaining wastewater is biologically activated carbon as usual. You may introduce into the processing apparatus 21. FIG. In short, wastewater containing an amount of organic matter that exceeds the amount of organic matter that can be treated in the biological activated carbon treatment device 21 may be introduced into the high-concentration wastewater treatment line 10.
In order to adjust the amount of wastewater to be distributed, the open / close states of the introduction pipe 21a and the valves 23 and 40a of the bypass line 40 may be adjusted.

  Further, the timing for measuring the TOC concentration of the waste water by the concentration measuring means 22 may be measured constantly or periodically.

  Furthermore, in said 2nd embodiment, although the valves 23 and 40a were used as a means to distribute the flow of waste water from the low concentration waste water treatment line 20 to the high concentration waste water treatment line 10, it is not limited to this, and automatic It is possible to use a known transfer means such as switching with a valve or providing a dedicated transfer pump to operate when necessary.

In the first and second embodiments, the inorganic waste water treatment line 30 is provided and the inorganic chemicals are separately treated. However, such an inorganic waste water treatment line 30 may be separately provided.
For example, an ion removal treatment device can be provided in the low-concentration wastewater treatment line 20 to treat wastewater containing organic chemicals at low concentrations and wastewater containing inorganic chemicals at the same time.

  Further, as in the first and second embodiments, in addition to the ion removal treatment device, the inorganic wastewater treatment line 30 is equipped with a filtration device such as a microfiltration membrane or an ultrafiltration membrane, a reverse osmosis membrane device, or electrodialysis. Other ion removal processing means such as an apparatus may be provided.

Furthermore, it is not a condition to treat the wastewater with the biological activated carbon treatment device 21 after treating the wastewater containing the inorganic chemicals with the ion removal treatment device 31 as in the first and second embodiments.
However, by introducing into the biological activated carbon treatment apparatus 21 in this way, even if organic chemicals are slightly contained in the wastewater containing inorganic chemicals, they can be removed.
Further, a biological activated carbon treatment device is provided in the inorganic wastewater treatment line 30 separately from the biological activated carbon treatment device 21 of the low concentration wastewater treatment line 20, and the wastewater after being treated by the biological activated carbon treatment device of the inorganic wastewater treatment line 30 is treated. You may collect | recover as collection | recovery water.

In the first and second embodiments, the case where the wastewater discharged from the manufacturing process of the semiconductor device or the liquid crystal flat display is collected for each process and directly introduced into each processing process has been described. May be processed with the processing method or the processing apparatus of the present invention.
Or, when there is a large amount of wastewater containing high-concentration organic chemicals, the amount of wastewater treated in the high-concentration wastewater treatment line can be adjusted by mixing a part of it with wastewater containing low-concentration organic chemicals. May be.
However, it is preferable that the wastewater introduced into the low-concentration wastewater treatment line is not mixed with wastewater subjected to biological treatment. This is because when biologically treated wastewater is mixed, the ability to decompose organic matter in biological activated carbon treatment, which is also a kind of biological treatment, is reduced.

  Furthermore, in said 1st and 2nd embodiment, although the filtration processing apparatus provided with the microfiltration membrane was used as a filtration processing apparatus, as a filtration processing apparatus, it is well-known, such as an ultrafiltration membrane and coagulation filtration, besides this The filtration means can be selected. Or the said filtration apparatus may be provided in a low concentration waste water treatment line and an inorganic waste water treatment line, and it is not necessary to provide a filtration apparatus.

Moreover, in said 1st and 2nd embodiment, although the reverse osmosis processing apparatus was provided in the high concentration wastewater treatment line and the waste_water | drain was isolate | separated into the concentrated water and the permeated water, it is indispensable to provide such a reverse osmosis treatment apparatus. Absent.
Or you may provide a reverse osmosis processing apparatus in a low concentration wastewater treatment line or an inorganic wastewater treatment line.

  Furthermore, in the first and second embodiments, the ultraviolet oxidative decomposition apparatus is used as the physicochemical oxidative decomposition means. However, as the oxidative decomposition means, other means for performing oxidative decomposition treatment with ozone, Other physicochemical oxidative decomposition means may be used.

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

(Example)
As an example, the waste water treatment apparatus similar to that of the first embodiment was used, and waste water treatment was performed with a treatment flow as shown in FIG.
That is, first, high-concentration organic wastewater having a TOC concentration of about 120 mg / L is introduced into a high-concentration treatment drainage line, and a biological treatment device (a fixed-bed biological treatment device is used in this embodiment), a filtration treatment device (this In the examples, an apparatus using an MF membrane was used) and then introduced into a reverse osmosis treatment apparatus (RO apparatus) to obtain RO treated water of high concentration organic waste water. At this time, the TOC concentration of the RO-treated water was about 1.1 mg / L.
The waste water is waste water from the liquid crystal 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, the high-concentration organic wastewater, the low-concentration organic wastewater, and the inorganic wastewater. Sorted as.

Next, the RO treated water was introduced into an oxidative decomposition treatment apparatus. As the oxidative decomposition treatment apparatus, an ultraviolet oxidative decomposition treatment apparatus of 300 L in an oxidation tank using a 1 kW high-pressure ultraviolet lamp (manufactured by Toshiba Lighting & Technology) was used, and the above-mentioned HRT (hydraulic residence time) 20 minutes, 900 L / h. Oxidative decomposition treatment of RO treated water was performed.
In addition, before introducing into the ultraviolet oxidative decomposition treatment apparatus, hydrogen peroxide 4 times the amount of oxygen consumption 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 0.22 mg / L.

Inorganic wastewater was treated with an ion removal treatment device (in this example, an ion exchange device, manufactured by Shinko Environmental Solution Co., Ltd.). The TOC concentration after the treatment with the ion removal treatment apparatus was 2.3 mg / L.
Further, the inorganic waste water after the ion removal treatment and the low concentration organic waste water having a TOC concentration of about 3.5 mg / L are mixed at 140 L / h, respectively, and the biological activated carbon treatment apparatus is used at a treatment amount of 280 L / h. Processed.

As the biological activated carbon treatment apparatus, a fixed bed downward flow type Bio-AC column (300 mmφ × 3.8 mH), activated carbon (140 L, particle size 1.3 to 1.6 mm spherical activated carbon) was used, and HRT = 30 minutes, The treatment was performed under a treatment condition of 280 L / h.
The power consumption per unit volume of waste water in the biological activated carbon treatment was 0.2 kWh / m ³ . Thereafter, the TOC concentration of the collected recovered water was reduced to about 0.24 mg / L.

(Comparative Example 1)
As Comparative Example 1, in place of the ultraviolet oxidative decomposition treatment device of the wastewater treatment device of the above example, a wastewater treatment device equipped with a biological activated carbon treatment device is used. Wastewater and inorganic wastewater were treated by a flow as shown in FIG.
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 RO-treated water was about 1.1 mg / L.
Next, the RO treated water was introduced into the biological activated carbon treatment apparatus at 280 L / h, and the treatment was performed under the treatment conditions of HRT = 30 minutes. As a result, the TOC concentration of treated water treated with the biological activated carbon treatment apparatus was as high as 1.0 mg / L, and could not be recovered and reused.
The power consumption per unit volume of waste water in the biological activated carbon treatment was 0.2 kWh / m ³ .
On the other hand, the inorganic wastewater and the low-concentration organic wastewater were each treated in the same manner as in the above example, and the TOC concentration of the obtained recovered water was about 0.24 mg / L.
The power consumption per unit waste water volume of the biological activated carbon treatment in the treatment of the inorganic waste water and the low concentration organic waste water was 0.2 kWh / m ³ .

(Comparative Example 2)
As Comparative Example 2, in place of the two biological activated carbon treatment devices of the wastewater treatment device of Comparative Example 1, a wastewater treatment device provided with one ultraviolet oxidative decomposition treatment device similar to that of the example was used. The treatment was performed in the flow as shown in FIG. 5 for treating the concentration organic wastewater, the low concentration organic wastewater, and the inorganic wastewater. That is, the high concentration organic wastewater was treated with the biological treatment apparatus and the filtration treatment in the same manner as in Example 1. Introduced sequentially into the equipment and reverse osmosis treatment equipment, RO treated water of high concentration organic waste water was obtained. The TOC concentration of the high concentration organic waste water at this time was about 1.1 mg / L.
Next, the untreated low-concentration organic wastewater and the inorganic wastewater after the ion removal treatment in the same manner as in the above example are mixed with the RO-treated water of the high-concentration organic wastewater as in the above example. The sample was introduced into the ultraviolet oxidative decomposition treatment apparatus and treated under the treatment conditions of 300 L / h and HRT = 28 minutes.
The power consumption of the entire device per unit waste water volume of Comparative Example 2 was 3.3 kWh / m ³ .

From the above results, it can be seen that the example consumes less power in the entire processing apparatus and the TOC concentration in the collected treated wastewater is lower than in each comparative example.
That is, when the total amount of waste water treated in the example and the comparative example 2 is the same amount (for example, the total amount of 3000 m ³ / day), as shown in Table 1, in the example, it becomes 1500 kWh / day, which is 9900 kWh of the comparative example 2. / Power consumption is suppressed compared to the day.

(Treatment capacity in biological activated carbon treatment equipment)
Next, the treatment capacity of the biological activated carbon treatment apparatus of the above example was examined.
As a result of the test, if the amount of TOC to be processed increases in the biological activated carbon device, the amount of microorganisms in the biological activated carbon layer increases at an accelerated rate, so the differential pressure (pressure loss in the biological activated carbon layer) also increases at an accelerated rate. At the same time, it was found that the treatment efficiency of microorganisms also decreased.
When this differential pressure exceeded 0.15 kg / cm ² , the treatment efficiency was significantly reduced.
The graph of FIG. 6 shows the results of measuring the relationship between the TOC amount (integrated amount) flowing into the biological activated carbon treatment device and the differential pressure using the biological activated carbon treatment device used in the above examples.
From the graph of FIG. 6, it can be seen that the differential pressure increases as the amount of TOC increases. In order to operate the biological activated carbon treatment apparatus at a differential pressure of 0.15 kg / cm ² or less, the activated carbon unit volume of the biological activated carbon treatment apparatus It is necessary to operate at an accumulated inflow TOC amount of 180 g / m ³ or less.

Furthermore, the relationship between the TOC concentration in the waste water and the water flow time for operating the biological activated carbon treatment apparatus at 180 g / m ³ at a treatment amount of 45 minutes in HRT is shown as a graph in FIG.
As can be seen from FIG. 7, if the TOC concentration in the wastewater is lower than 10 mg / L, the biological activated carbon treatment apparatus can maintain the performance even if it operates for 12 hours.
On the other hand, when the TOC concentration in the wastewater is 10 mg / L or more, if the treatment is continued with the biological activated carbon treatment apparatus, the differential pressure exceeds 0.15 kg / cm ² in less than 12 hours, and the treatment efficiency begins to decline.
In this case, as described in the second embodiment, the low-concentration wastewater treatment line is distributed to the high-concentration wastewater treatment line via a distribution means such as a bypass line, and is processed by the ultraviolet oxidative decomposition treatment apparatus. It is preferable to do.

1: Waste water treatment equipment,
10: High concentration wastewater treatment line,
11: UV oxidative decomposition treatment device,
12: biological treatment device,
13: Filtration processing device,
14: Reverse osmosis membrane treatment device,
15: collection device,
20: Low concentration wastewater treatment line,
21: Biological activated carbon treatment device,
22: Concentration measuring means,
23: valve,
30: inorganic wastewater treatment line,
31: Ion removal processing device,
40: Bypass line,
40a: valve

Claims (3)

Of the wastewater discharged from the manufacturing process, wastewater containing high concentration organic chemicals is introduced into the high concentration wastewater treatment line, wastewater containing low concentration organic chemicals is introduced into the low concentration wastewater treatment line, In the high-concentration wastewater treatment line, a biological treatment process that treats organic matter in the wastewater with microorganisms and a physicochemical oxidative decomposition process are performed. In the low-concentration wastewater treatment line, wastewater that is unbiologically treated water is converted into microorganisms. biological treatment step of treating is performed by,
Of the wastewater discharged from the manufacturing process, wastewater containing inorganic chemicals is introduced into an inorganic wastewater treatment line, and in the inorganic wastewater treatment line, an ion removal treatment step for removing ions in the wastewater is performed. This
In the low-concentration wastewater treatment line, before carrying out the biological treatment process, the organic matter concentration in the wastewater is measured, and when the organic matter concentration is higher than a predetermined concentration, at least a part of the wastewater is passed through the Introduced into the physicochemical oxidative decomposition process of the concentration wastewater treatment line,
Waste water treatment method characterized that you process wastewater which has been treated by the ion removing treatment step in the biological treatment process of the low-concentration waste water treatment line. In the high-concentration wastewater treatment line, a reverse osmosis membrane treatment step is performed in which wastewater is permeated by a reverse osmosis membrane, and the wastewater treated in the reverse osmosis membrane treatment step is treated in the physicochemical oxidative decomposition step. Item 2. A wastewater treatment method according to Item 1 . The wastewater treatment method according to claim 1 or 2, wherein the physicochemical oxidative decomposition step performs oxidative decomposition with ultraviolet rays or ozone.

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