JP2009000591A - Water treatment method of organic matter-containing wastewater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water treatment method of organic matter-containing wastewater, which maintains a permeated water flux of an RO membrane in the long term, and enables a longer-term water treatment in highly-concentrated organic matter-containing wastewater. <P>SOLUTION: The water treatment method of the organic matter-containing wastewater comprises the steps of treating the organic matter-containing wastewater by a biological treatment 2, of adding alkaline chemicals to the obtained biologically treated water and subjecting the water to an ozone treatment 4, and of, after the obtained ozonated water is filtrated 5, carrying out passing water through a reverse osmosis membrane 8. The water treatment method of the organic matter-containing wastewater comprises the steps of treating the organic matter-containing wastewater by the biological treatment 2, of ozonating the obtained biologically treated water 4, and of, after the ozonated water is filtrated 5 and subjecting the water to a reduction-treatment 6, carrying out passing water through the reverse osmosis membrane 8. The water treatment method of the organic matter-containing wastewater comprises the steps of treating the organic matter-containing wastewater by the biological treatment 2, of ozonating the obtained biological treated water 4, and of, after the obtained ozonated water is subjected to an activated carbon-filtration-treatment 6, carrying out passing water through the reverse osmosis membrane 8. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a water treatment method for organic matter-containing wastewater.

In semiconductor factories and liquid crystal factories, organic chemicals are used for cleaning solutions, developer solutions, stripping solutions, and the like, and wastewater from these factories contains organic substances. When wastewater containing these organic substances (hereinafter referred to as organic substance-containing wastewater) is recovered and reused in a pure water production apparatus, reduction of organic substances is most important in the recovery apparatus.
Conventionally, when organic matter-containing wastewater containing organic matter at a low concentration is treated with water and recovered and reused, the organic matter-containing wastewater is subjected to oxidation treatment such as ozone treatment or ultraviolet oxidation treatment using an ozone oxidation device or ultraviolet oxidation device, Alternatively, after biological treatment using a filler, it is processed into a microfiltration membrane (MF membrane) treatment or reverse osmosis membrane (RO membrane) treatment with a reverse osmosis device (RO device), and then recovered into a pure water production device. Has been. A water treatment method combining a biological treatment, an ozone oxidation treatment, and an ultraviolet oxidation device has also been proposed. (See Patent Document 1)

However, when an organic matter-containing wastewater containing a high concentration of organic matter is treated with the above method, the running cost increases as the maintenance of the oxidizer increases and the replacement frequency of the MF membrane or RO membrane increases. There are disadvantages. Specifically, in a high-concentration organic substance-containing wastewater having an organic carbon (TOC) concentration of 10 mg / L or more, when an attempt is made to perform water treatment only by ozone treatment without performing biological treatment, the amount of ozone added is usually TOC. 10 times or more of the concentration, that is, the amount of ozone added is required to be 100 mg / L or more, which increases the cost and running cost of the ozone generator.
For these reasons, when trying to collect wastewater containing organic matter having a high TOC concentration of 10 mg / L or more, biological treatment that is cost effective is often used. In general, high-concentration organic substance-containing wastewater is first biologically treated, and the resulting biologically treated water is filtered by MF membrane or sand filtration, and then treated by reverse osmosis membrane with RO membrane before producing pure water. It is collected into the device.
JP-A-7-328693

However, when the organic matter-containing wastewater is biologically treated, biological metabolites derived from biological treatment are generated in the biologically treated water. These biological treatment-derived biological metabolites are present in the treated water in a polymer form, but are not removed by filtration treatment with a large pore size and reach the subsequent RO device, causing the RO membrane to be clogged. There has been a problem of reducing the permeate flux. In addition, when an MF membrane is installed after the biological treatment, similar membrane blockage is caused, and the permeate flux of the MF membrane is reduced.
This invention is made | formed in view of the said situation, Comprising: The permeated water flux of RO membrane is maintained for a long term, Therefore Organic substance containing waste_water | drain which can perform long-term water treatment in highly concentrated organic substance containing waste_water | drain The purpose of the water treatment method.

In order to achieve the above object, the present invention employs the following configuration.
[1] Treat organic-containing wastewater by biological treatment, add an alkaline agent to the resulting biologically treated water, and then treat with ozone. Filter the resulting ozone-treated water before passing it through a reverse osmosis membrane. A water treatment method for organic matter-containing wastewater.
[2] Treating organic matter-containing wastewater by biological treatment, treating the resulting biologically treated water with ozone, filtering the obtained ozone-treated water, reducing it, and passing it through the reverse osmosis membrane A water treatment method for waste water containing organic matter.
[3] The water treatment method for organic matter-containing wastewater according to [1] or [2], wherein the filtration treatment is sand filtration and / or activated carbon filtration.
[4] Organic matter characterized by treating organic wastewater by biological treatment, treating the resulting biological treated water with ozone, filtering the obtained ozone treated water with activated carbon, and then passing it through a reverse osmosis membrane Water treatment method for contained wastewater.

  According to the water treatment method for organic matter-containing wastewater of the present invention, the permeated water flux of the RO membrane can be maintained for a long time, and thus long-term water treatment can be performed in the high-concentration organic matter-containing wastewater.

  In water treatment of wastewater containing organic matter at a high concentration, in the method for treating wastewater containing organic matter according to the present invention, the wastewater containing organic matter is first biologically treated, and then the obtained biologically treated water is treated with ozone. The obtained ozone-treated water is subjected to filtration treatment, and the obtained filtration-treated water is further passed through a reverse osmosis membrane. For the purpose of decomposing residual ozone, addition of alkaline agent before ozone treatment (form 1), reduction treatment after filtration (form 2, form 3), or activated carbon filtration treatment that combines filtration and reduction treatment (Mode 4) is performed.

As Embodiment 1 of the present invention, a water treatment method for organic matter-containing wastewater that includes the addition of an alkaline agent before ozone treatment will be described with reference to the flowchart of FIG.
First, the organic matter-containing wastewater is sent from the raw water tank 1 to the biological treatment tank 2 where it is biologically treated. The biologically treated water obtained by biological treatment in the biological treatment tank 2 is stored in the biologically treated water storage tank 3, where an alkaline agent is added. The biologically treated water to which the alkaline agent has been added is sent to the ozone reaction tank 4 and subjected to ozone treatment. The obtained ozone-treated water is then sent to the filter 5 and filtered (deturbation treatment). The obtained filtered water is stored in the filtered water storage tank 6 and then sent to the RO device 8. The filtered water is subjected to reverse osmosis membrane treatment by an RO membrane provided in the RO device 8. Through such a water treatment step, reverse osmosis membrane treated water (RO permeated water) can be obtained from organic matter-containing wastewater. In addition, RO permeated water is sent to a pure water manufacturing apparatus as collection | recovery water, for example, and is reused.

The biological treatment performed in the biological treatment tank 2 is performed for the purpose of decomposing organic matter in the organic matter-containing wastewater. By performing biological treatment at the initial stage of the water treatment process, it is possible to efficiently decompose organic matter in wastewater containing high concentration organic matter, and to minimize outflow of organic matter to the subsequent stage.
It is preferable to fill the biological treatment tank 2 with a filler and to hold microorganisms therein. By holding the microorganisms in the filler, the microorganisms can be stably kept in the biological treatment tank 2. Thereby, not only stable biological treatment is possible, but an increase in the load on the subsequent stage due to excessive outflow of microorganisms on the subsequent stage can be avoided.
It does not specifically limit as a filler, A well-known filler can be applied. For example, a fixed bed biological carrier using fibrous activated carbon, a continuous foam structure resin, or a fluidized bed carrier obtained by coating a porous ceramic with a microorganism adsorbent can be used.

The addition of the alkaline agent in the biologically treated water storage tank 3 is performed for the purpose of decomposing ozone added by the ozone treatment before reaching the RO device 8. When the ozone remaining after the ozone treatment reaches the RO device 8 in the subsequent stage while being contained in the ozone-treated water, the RO film is damaged and the deterioration is promoted. Then, the residual ozone in ozone treatment water is decomposed | disassembled rapidly by adding an alkaline agent with respect to the filtration treatment water sent to the ozone reaction tank 4, and making it the alkali which is easy to decompose | disassemble ozone beforehand. Thereby, residual ozone does not reach the downstream RO device 8, and the deterioration of the RO membrane due to the residual ozone can be prevented.
Note that the alkali agent may be added between the biological treatment tank 2 and the ozone reaction tank 4. Accordingly, the alkali agent is added in the biologically treated water storage tank 3 shown in the form 1 of FIG. 1, for example, a water pipe connecting the biologically treated water tank 2 and the biologically treated water storage tank 3, or biologically treated water. An addition device (not shown) of an alkaline agent may be provided in the middle of the water pipe connecting the storage tank 3 and the ozone reaction tank 4 and added from here.
In order to rapidly decompose residual ozone after decomposing biological metabolites, it is preferable to maintain the pH of ozone-treated water at 9.5 to 11. Therefore, the addition amount of the alkaline agent is controlled so as to be within this range. When the pH of the ozone treated water is lower than 9.5, residual ozone is difficult to be decomposed. When it exceeds pH 11, the ion load of the RO apparatus 8 of the latter stage becomes large, and the cost of the alkaline agent naturally increases.
In addition, as an alkaline agent to be added, a known alkaline agent such as sodium hydroxide can be used.

  The addition of the alkaline agent can obtain the following effects in addition to the decomposition of residual ozone. When the hardly biodegradable organic matter that has not been decomposed by the biological treatment is present in the biologically treated water, the organic matter becomes an easily biodegradable organic matter by the ozone treatment. This easily biodegradable organic matter may become a nutrient source for microorganisms that survive without being sterilized even by ozone treatment, and may generate slime due to the propagation of microorganisms in the subsequent filter 5 or the RO device 8. If the treated water that flows after the ozone reactor is kept alkaline at pH 9.5 or higher as in the first embodiment of the present invention, the growth of microorganisms can be suppressed. That is, since bacteriostatic properties can be imparted to the treated water itself, generation of slime in the subsequent stage can be prevented.

  The ozone treatment in the ozone reaction tank 4 is performed for the purpose of partial decomposition of biological metabolites contained in biologically treated water and sterilization of biologically treated water. In addition, it is not the objective of the ozone treatment in this invention to decompose | disassemble the hardly decomposable organic substance which was not decomposed | disassembled by biological treatment.

  The main factor causing RO membrane occlusion is a high molecular weight biological metabolite, which is partially decomposed by ozone treatment in the ozone reaction tank 4 to prevent the RO membrane from being blocked by the high molecular weight biological metabolite. it can. Therefore, the permeated water flux of the RO membrane can be maintained for a long time, and a long-term water treatment can be performed in wastewater containing a high concentration of organic matter. The high molecular weight biological metabolite can be converted into a substance that does not block the RO membrane only by partial decomposition, and does not need to be completely decomposed to carbonate ions. Therefore, the amount of ozone added is small, and the cost of ozone addition can be kept low.

  At this time, the present inventors added about twice as much ozone in terms of mass to the TOC amount of the high molecular weight biological metabolite, so that the high molecular weight biological metabolite contained in the filtered water is obtained. It was found that can be partially decomposed. In addition, what is necessary is just to convert to about 10% of the TOC density | concentration of the organic matter containing waste water before biological treatment as a standard of the quantity of the high molecular weight biological metabolite in filtration treated water. For example, when the TOC concentration of the organic matter-containing wastewater before biological treatment is about 200 mg / L, the TOC of the high molecular weight biological metabolite component is about 10 mg / L, and therefore the ozone addition amount may be about 20 mg / L. .

  The method for adding ozone to the ozone reaction tank 4 is not particularly limited, and a known addition method can be applied. For example, an aeration method in which ozone gas is blown into water through an aeration tube, a method of dissolving ozone gas using a static mixer, a method of sucking ozone gas using an ejector, and the like can be mentioned. Further, as the ozone treatment method, either batch treatment or continuous treatment may be used.

The filtration process by the filter 5 is performed to remove suspended substances contained in the treated water. Although it does not specifically limit as a method of filtration processing, Sand filtration using sand for a filter medium and activated carbon filtration using activated carbon are used preferably. Furthermore, it is preferable that these filtration methods have a back washing mechanism. Sand filtration and activated carbon filtration are less expensive to maintain than ultrafiltration membranes (UF membranes) and MF membranes, which are other filtration methods, and require less pressure to be applied to the treated water when passing water. Easy to handle.
The filtered water that has been filtered by the filter 5 is stored in the filtered water storage tank 6 and then fed to the RO device 8.

The filtered water is supplied to the RO device 8 and is subjected to reverse osmosis membrane treatment by the RO membrane provided in the RO device 8 to become RO permeated water from which impurities at the ion level have been removed.
The material of the RO membrane is not particularly limited, and a known RO membrane made of cellulose acetate or aromatic polyamide can be used. Moreover, it does not specifically limit as a structure of a film | membrane, For example, well-known structures, such as a hollow fiber membrane, a spiral membrane, and a tubular membrane, can be used.

In addition, regarding the decomposition | disassembly of the residual ozone mentioned above, the method by a reduction process other than the method by addition of an alkaline agent may be used. That is, the addition of the alkaline agent is omitted, and instead, a reduction treatment may be performed to decompose residual ozone. Examples of the reduction treatment include a reduction treatment using the reducing action of activated carbon, a reduction treatment using a reducing agent such as sodium sulfite and sodium bisulfite. In addition, when ozonolysis is carried out by the method by a reduction process, bacteriostatic property is not provided to the treated water. Therefore, a disinfectant is preferably added to the treated water so that slime is not generated in the steps after the filter 5.
As a reduction treatment using the reducing action of activated carbon, as in the second embodiment of the present invention shown in FIG. 2, a bactericidal agent is added between the ozone reaction tank 4 and the filter 5 to generate slime in the subsequent stage. There is a method in which the activated carbon tower 7 is provided between the filtered treated water storage tank 6 and the RO device 8 and the residual ozone in the treated water is decomposed by the reducing action of the activated carbon. In addition, about each process of the flowchart of FIG. 2, about the process functionally similar to the flowchart of FIG. 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

Since the reduction treatment may be performed between the filtration treatment and the reverse osmosis membrane treatment, the activated carbon tower 7 may be provided between the filter 5 and the filtration treated water storage tank 6.
As the disinfectant, known disinfectants can be used, but sodium hypochlorite having immediate effect is preferably used. The amount of sodium hypochlorite added is preferably such that the residual chlorine concentration in the biologically treated water is 0.5 mg / L or more. By filtering the biologically treated water whose residual chlorine concentration is maintained at 0.5 mg / L or more, slime generation due to the growth of microorganisms in the filter 5 can be effectively suppressed.

As a reduction treatment using a reducing agent such as sodium sulfite or sodium bisulfite, for example, as shown in embodiment 3 of FIG. 3, by adding a reducing agent to the filtered water in the filtered water storage tank 6 Reduction processing is performed. The reducing agent is not limited to addition into the filtered water storage tank 6, but is a water pipe connecting the filter 5 and the filtered water storage tank 6, or a transmission pipe connecting the filtered water storage tank 6 and the RO device 8. A reducing agent addition device (not shown) may be provided in the middle of the water pipe, and the reducing agent may be added therefrom.
The addition amount of the reducing agent may be an amount that can remove residual ozone, and is appropriately adjusted according to the residual ozone amount in the filtered water. In addition, about each process of the flowchart of FIG. 3, about the process functionally similar to the flowchart of FIG. 1, 2, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  Moreover, in this invention, activated carbon is used for the filter material of the filter 5 and activated carbon filtration processing of ozone treatment water is carried out like the flowchart of the form 4 shown in FIG. Then, the water may be passed through the reverse osmosis membrane to serve both as a filtration treatment and a reduction treatment. In addition, about each process of the flowchart of FIG. 4, about the process functionally similar to the flowchart of FIG. 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  According to the present invention, the macromolecular biological metabolite derived from biological treatment is partially decomposed with a small amount of ozone, so that the RO membrane can be prevented from being blocked and the permeate flux of the RO membrane can be maintained for a long time. Accordingly, long-term water treatment in wastewater containing organic matter with a high concentration becomes possible. In addition, the cost of ozone addition can be reduced by adding a small amount of ozone. Furthermore, the water treatment method from organic matter-containing wastewater of the present invention can be applied to, for example, prevention of clogging of the MF membrane in addition to prevention of clogging of the RO membrane.

Hereinafter, the present invention will be specifically described with reference to examples. In addition, this invention is not limited by these Examples. The measuring method in an Example is shown next.
(Measurement of permeate flux)
The RO membrane permeate flux is calculated by dividing the RO permeate flow rate [m ³ / d] by the RO membrane area [m ² ] and operating pressure [(co-feed water pressure + concentrated water pressure) / 2-permeate water pressure. The value divided by [MPa] was converted to the following conditions.
m / d at 14.7MPa ・ 25 ℃

(Example 1)
According to the process of FIG. 1 which is the form 1 of this invention, the high concentration organic substance containing waste_water | drain was processed. As the high concentration organic matter-containing wastewater, organic matter-containing wastewater containing about the same amount of isopropyl alcohol (IPA) and tetrahydroammonium aqueous solution (TMAH) and having a TOC amount of about 50 mg / L was used.
The organic matter-containing wastewater stored in the raw water tank 1 is sent to a biological treatment tank 2 filled with a felt cloth-like molded body of fibrous activated carbon as a biological carrier, and the residence time of the organic matter-containing wastewater in the biological treatment tank 2 is set to 0. Biological treatment was performed by passing water from the bottom of the tank so as to be 8 hours, thereby obtaining biologically treated water by overflow from the top of the tank. In the biological treatment tank 2, aeration was performed from the bottom of the tank at a water flow rate (LV) of 10 m / h.

Next, the obtained biologically treated water was stored in the biologically treated water storage tank 3, where sodium hydroxide was added as an alkaline agent to adjust the pH of the filtered treated water. In addition, the addition amount of sodium hydroxide was controlled so that the ozone treatment water sent from the ozone reaction tank 4 showed pH 10.0-10.5.
Next, the filtered water to which sodium hydroxide has been added is sent to the ozone reaction tank 4, and the ozone treatment is performed by passing the water downward through the tank to the 4 m-high ozone reaction tank 4 with a reaction time of 6 minutes. The ozone-treated water was obtained from the lower part of the ozone reaction tank 4. In addition, ozone is added to the ozone reaction tank 4 by supplying ozone generated by an ozone generator (not shown) from an air diffuser installed at the bottom of the ozone reaction tank 4 and mixing it with filtered water. It was conducted. The amount of ozone added was 10.0 mg / L.

Next, the ozone-treated water was passed through a filter 5 by sand filtration to perform filtration (deturbation treatment). The filtration method of the filter 5 was sand filtration using sand.
The obtained filtered treated water is stored in the filtered treated water storage tank 6 and then sent to the RO device 8 to perform reverse osmosis membrane treatment at a recovery rate of 90%. Measured at 1 month after operation and 3 months after operation. The results are shown in Table 1. A cross-linked wholly aromatic polyamide low-pressure RO membrane (model number: LF10, manufactured by Nitto Denko Corporation) was used as the RO membrane.

(Comparative Example 1)
Water treatment of organic matter-containing wastewater was performed under the same conditions as in Example 1 except that the ozone treatment of the ozone reaction tank 4 in Example 1 was not performed and the biologically treated water in the biologically treated water storage tank 3 was directly fed to the filter 5. The RO permeated water flux in the RO device 8 was measured at the initial stage of operation, after one month of operation, and after three months of operation. The results are shown in Table 1.

(Comparative Example 2)
According to the form shown in FIG. 5, the water treatment of the organic substance containing waste water was performed. In addition, the organic matter containing waste water same as Example 1 was used for the organic matter containing waste water.
First, after adding sodium hydroxide as an alkaline agent from the middle of the water pipe through which the organic matter-containing wastewater flows to the organic matter-containing wastewater sent from the raw water tank 1 to the ozone reaction tank 4, the ozone treatment in the ozone reaction tank 4 Went. In addition, the addition amount of sodium hydroxide was controlled so that the ozone treatment water sent from the ozone reaction tank 4 showed pH 10.0-10.5.
The ozone treatment was performed by passing water through the ozone reaction tank 4 having a height of 4 m in a downward flow from the upper part of the tank for a reaction time of 6 minutes, and ozone treated water was obtained from the lower part of the ozone reaction tank 4. In addition, ozone is added to the ozone reaction tank 4 by supplying ozone generated by an ozone generator (not shown) from an air diffuser installed in the lower part of the ozone reaction tank 4 and mixing it with filtered water. It was conducted. The amount of ozone added was 10.0 mg / L. In addition, about each process of the flowchart of FIG. 5, about the process functionally similar to the flowchart of FIG. 1, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

The ozone-treated water sent from the ozone reaction tank 4 was stored in the ozone-treated water storage tank 9, and hydrochloric acid was added so that the ozone-treated water in the ozone-treated water storage tank 9 had a pH of 7.0. The addition of hydrochloric acid was performed to neutralize the pH of ozone-treated water having a pH of 10.0 to 10.5 to a pH that does not affect the biological treatment of the subsequent stage.
This ozone-treated water is sent to the biological treatment tank 2 filled with a felt cloth-like molded body of fibrous activated carbon as a biological carrier, and the residence time of the organic substance-containing wastewater in the biological treatment tank 2 is 0.8 h. Biological treatment was performed by passing water from the lower part to obtain biological treatment water by overflow from the upper part of the tank. In the biological treatment tank 2, aeration was performed from the bottom of the tank at a water flow rate (LV) of 10 m / h.
The obtained biologically treated water was stored in the biologically treated water storage tank 3, where 2.0 mg / L of sodium hypochlorite was added as a disinfectant to sterilize microorganisms mixed in the biologically treated water. . Further, the biologically treated water was supplied to the filter 5 and filtered (deturbation treatment), and the obtained filtered water was stored in the filtered water storage tank 6.

Subsequently, the filtered water was sent to the activated carbon tower 7 where a reduction treatment with activated carbon was performed to remove residual chlorine in the filtered water. In the activated carbon tower 7, activated water was obtained by passing water downward from the top of the tower at a space velocity (SV) of 10 / h. Further, in the filtered water obtained from the filter 5, 0.05 to 0.1 mg / L of residual chlorine was detected, but no residual chlorine was detected in the activated carbon treated water obtained from the activated carbon tower 7. Therefore, it was confirmed that residual chlorine was removed by activated carbon.
Furthermore, the activated carbon treatment water obtained is sent to the RO device 8 and the reverse osmosis membrane treatment is performed at a recovery rate of 90%. The permeate flux of the RO membrane at that time is the initial operation, one month after the operation, and Measurements were taken at the end of the month. The results are shown in Table 1. A cross-linked wholly aromatic polyamide low-pressure RO membrane (model number: LF10, manufactured by Nitto Denko Corporation) was used as the RO membrane.

(Evaluation)
In Comparative Example 1 in which no ozone treatment was performed, the temperature decreased to 0.41 m / d at 14.7 MPa · 25 ° C. (35.8% of the initial permeate flux) in one month, and 0.30 m / after three months. d at 14.7 MPa · 25 ° C. (26.2% of initial permeate flux).
In Comparative Example 2 in which the ozone treatment is performed before the biological treatment, the pressure drops to 0.45 m / d at 14.7 MPa · 25 ° C. (37.5% of the initial permeate flux) in one month, and after three months it becomes 0. It decreased to .29 m / d at 14.7 MPa · 25 ° C. (24.2% of the initial permeated water flux), and the permeated water flux (flux) was reduced as much as Comparative Example 1.
On the other hand, in Example 1, the RO permeate flux maintained about 88% of the initial permeate flux even when the water flowed for 3 months.
From this result, it was confirmed that ozone treatment was necessary to prevent the RO membrane from being clogged in the water treatment of wastewater containing organic matter with a high concentration. Moreover, it was confirmed that the RO membrane can be blocked for a long period of time by performing the ozone treatment after the biological treatment. From this, in Example 1, it is suggested that the high molecular weight biological metabolite that causes the RO membrane to be blocked is converted to a substance that does not block the RO membrane by the ozone treatment. Met.

  By using the organic matter-containing wastewater treatment method of the present invention, a substance that does not block the RO membrane by partially decomposing a macromolecular biological metabolite contained in the filtered water of biologically treated water by adding a small amount of ozone. It is possible to change to. As a result, the permeated water flux of the RO membrane can be maintained for a long period of time, and thus a long-term water treatment can be performed in the high concentration organic matter-containing waste water.

The flowchart which showed the process of the water treatment of the organic substance containing waste_water | drain which is the form 1 of this invention. The flowchart which showed the process of the water treatment of the organic substance containing waste_water | drain which is the form 2 of this invention. The flowchart which showed the process of the water treatment of the organic substance containing waste_water | drain which is the form 3 of this invention. The flowchart which showed the process of the water treatment of the organic substance containing waste_water | drain which is the form 4 of this invention. The flowchart which showed the process of the water treatment of the organic substance containing waste_water | drain which is a form of the comparative example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Raw water tank 2 Biological treatment tank 3 Biologically treated water storage tank 4 Ozone reaction tank 5 Filter 6 Filtered water storage tank 7 Activated carbon tower 8 RO device 9 Ozone treated water storage tank

Claims (4)

  It is characterized by treating wastewater containing organic matter by biological treatment, adding an alkaline agent to the resulting biologically treated water and then performing ozone treatment, filtering the obtained ozone treated water and then passing it through a reverse osmosis membrane. Water treatment method for organic matter-containing wastewater.   It is characterized by treating organic matter-containing wastewater by biological treatment, treating the obtained biological treated water with ozone, filtering the obtained ozone-treated water, and then reducing the water before passing it through the reverse osmosis membrane. Water treatment method for wastewater containing organic matter.   The said water treatment is sand filtration and / or activated carbon filtration, The water treatment method of the organic matter containing waste water of Claim 1 or 2 characterized by the above-mentioned. Organic matter-containing wastewater is characterized by treating organic matter-containing wastewater by biological treatment, treating the resulting biologically treated water with ozone, and filtering the resulting ozone-treated water with activated carbon before passing it through a reverse osmosis membrane. Water treatment method.

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