JP2014221449A - Method and apparatus for processing water containing organic hardly-decomposable substance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for processing water containing organic hardly-decomposable substances that can reduce COD concentration derived from organic hardly-decomposable substances such as PVA and deposition products, in Fenton treatment (oxidation treatment) of water containing the organic hardly-decomposable substances of high concentration.SOLUTION: A method for processing water containing organic hardly-decomposable substances includes an oxidation step for oxidizing the water containing organic hardly-decomposable substances having a concentration of 1,500 mg/L or more in an oxidation tank 12 by adding hydrogen peroxide from a hydrogen peroxide feed line 16 and an iron compound from an iron compound feed line 20, and a slaked lime adding step for adding slaked lime from a slaked lime feed line 24 to the oxidized water in the oxidation tank 12.

Description

  The present invention relates to a technique for treating a water containing a hardly decomposable organic substance such as polyvinyl alcohol and a treatment apparatus.

  Polyvinyl alcohol (hereinafter sometimes referred to as PVA) is used worldwide as a raw material for synthetic fiber vinylon, but in recent years, due to excellent stability and physical properties, emulsion stabilizers, fiber processing, film, packaging It is used as a material. For this reason, PVA is used in chemical factories and dyeing factories that manufacture the above products, and some of them are discharged as polyvinyl alcohol-containing water such as factory effluents and waste liquids.

  Usually, PVA is known as a hardly decomposable organic substance that is difficult to be decomposed by general microorganisms. However, it has been reported that PVA can be biodegraded by fully acclimatizing activated sludge.

  In addition, it has been proposed to add an oxidizing agent to a hardly decomposable organic substance and perform oxidation treatment (Fenton treatment) (see, for example, Patent Documents 1 and 2).

  In addition, as other treatment methods for hardly decomposable organic substances, a method of coagulating and precipitating using a special coagulant or methacrylic acid, a method of treating by electrolysis, and the like have been proposed.

JP2011-50887A JP 2004-89854 A

  However, regarding biological treatment of persistent organic substances, it is said that the activated sludge has a very low decomposition rate and takes 20 days or more for the treatment time. In addition, there are problems such as an increase in the installation area of the wastewater treatment device and difficulty in maintaining special degrading bacteria in the activated sludge. There is.

  Moreover, the above-mentioned biological treatment is intended for low-concentration hardly decomposable organic matter, and treatment of high concentration hardly-degradable organic matter has not been established. In the case of biologically treating a highly-concentrated organic substance having a high concentration, a treatment including a plurality of steps such as incineration, physicochemical treatment, biological treatment, and activated carbon is necessary in the subsequent stage, which is not practical.

  In addition, Fenton treatment (oxidation treatment) using an oxidizing agent is expected as a practical decomposition treatment method, but it remains without being completely decomposed even when water containing a hardly decomposable organic substance such as PVA is treated with Fenton. Or the COD derived from the decomposition products remains. In particular, in the case of water containing highly degradable organic substances having a high concentration of 1500 mg / L or more, the COD concentration after treatment remains 1000 mg / L or more, so it is necessary to install a plurality of treatment facilities such as biological treatment and activated carbon treatment in the subsequent stage. Yes, it is neither economical nor space practical. Therefore, it has been conventionally considered difficult to apply Fenton treatment (oxidation treatment) in water containing highly degradable organic matter.

  In addition, the method of coagulating and precipitating using a special coagulant or methacrylic acid has problems such as high chemical cost for coagulation and a large amount of sludge generation. In addition, the electrolysis method is difficult to decompose. There are problems such as insufficient decomposition rate of organic matter.

  Accordingly, an object of the present invention is to provide a hardly decomposed substance capable of reducing the concentration of COD derived from a hardly decomposed organic substance such as PVA or a decomposition product in the Fenton treatment (oxidation treatment) of water containing a highly concentrated hardly decomposed organic substance. It is providing the processing method and processing apparatus of water containing volatile organic substance.

  The method for treating difficult-to-decompose organic substance-containing water according to an embodiment of the present invention includes an oxidation treatment step in which an iron compound and hydrogen peroxide are added to a hardly-degradable organic substance-containing water of 1500 mg / L or more to oxidize, A slaked lime addition step of adding slaked lime to the treated water subjected to oxidation treatment.

  In the method for treating difficult-to-decompose organic substance-containing water, the hardly-degradable organic substance-containing water is preferably polyvinyl alcohol-containing water.

  In the method for treating difficult-to-decompose organic matter-containing water, the iron compound preferably contains ferrous sulfate.

  In the method for treating difficult-to-decompose organic substance-containing water, the oxidation treatment is preferably performed in a single reaction tank.

  Moreover, the treatment apparatus of the hardly decomposable organic substance-containing water according to the present embodiment includes an oxidation treatment means for performing an oxidation treatment by adding an iron compound and hydrogen peroxide to 1500 mg / L or more of the hardly decomposable organic substance-containing water, and the oxidation It is an apparatus provided with the slaked lime addition which adds slaked lime to the treated water which processed.

  Moreover, it is preferable that the said hard-to-decompose organic substance containing water is a polyvinyl alcohol containing water as for the processing apparatus of the said hard-to-decompose organic substance containing water.

  Moreover, it is preferable that the said iron compound contains ferrous sulfate in the processing apparatus of the said hardly decomposable organic substance containing water.

  Moreover, in the said processing apparatus of the hardly decomposable organic substance containing water, it is preferable that the said oxidation treatment means is a single reaction tank.

  ADVANTAGE OF THE INVENTION According to this invention, the density | concentration of COD derived from a decomposition product can be reduced in the Fenton process (oxidation process) of highly concentrated organic substance-containing water.

It is a schematic diagram which shows an example of a structure of the processing apparatus of the hardly decomposable organic substance containing water which concerns on this embodiment. It is a schematic diagram which shows another example of a structure of the processing apparatus of the hardly decomposable organic substance containing water which concerns on this embodiment.

  Embodiments of the present invention will be described below. This embodiment is an example for carrying out the present invention, and the present invention is not limited to this embodiment.

  FIG. 1 is a schematic diagram illustrating an example of a configuration of a treatment apparatus for water containing hardly decomposable organic matter according to the present embodiment. The processing apparatus 1 shown in FIG. 1 is a batch type processing apparatus, and includes an inflow line 10, an oxidation treatment reaction tank 12, a hydrogen peroxide storage tank 14 containing hydrogen peroxide, and hydrogen peroxide addition as hydrogen peroxide addition means. Line 16, iron compound storage tank 18 containing iron compound, iron compound addition line 20 as iron compound addition means, slaked lime storage tank 22 containing slaked lime, slaked lime addition line 24 as slaked lime addition means, polymer flocculant A coagulant storage tank 26 to be accommodated, a coagulant addition line 28 as a coagulant addition means, and discharge lines 30a and 30b are provided. The oxidation treatment reaction tank 12 is desirably provided with a stirring device 32 such as a stirring blade, a pH meter 34 and the like. It is desirable to install a pump for adjusting the flow rate of each drug in the hydrogen peroxide addition line 16, the iron compound addition line 20, the slaked lime addition line 24, the flocculant addition line 28, and the like.

  As shown in FIG. 1, an inflow line 10 and discharge lines 30 a and 30 b are connected to the oxidation treatment reaction tank 12. One end of the hydrogen peroxide addition line 16 is connected to the hydrogen peroxide storage tank 14, and the other end is connected to the oxidation treatment reaction tank 12. One end of the iron compound addition line 20 is connected to the iron compound storage tank 18, and the other end is connected to the oxidation treatment reaction tank 12. One end of the slaked lime addition line 24 is connected to the slaked lime storage tank 22, and the other end is connected to the oxidation treatment reaction tank 12. One end of the flocculant addition line 28 is connected to the flocculant storage tank 26, and the other end is connected to the oxidation treatment reaction tank 12.

  The iron compound accommodated in the iron compound storage tank 18 is not particularly limited as long as it is an iron compound that can be used in oxidation treatment (Fenton treatment) of a hardly decomposable organic substance using hydrogen peroxide. Examples thereof include iron sulfate such as ferrous sulfate, iron chloride such as ferrous chloride, iron citrate, EDTA iron, and iron powder. In particular, ferrous sulfate or ferrous chloride is preferably used from the viewpoint of economy and the like.

  The polymer flocculant accommodated in the flocculant storage tank 26 is an anionic polymer organic flocculant such as alginic acid or a salt thereof, chitosan, dimethylaminoethyl (meth) acrylate tertiary salt and / or quaternary salt (for example, , A cationic polymer organic flocculant such as a polymer of methyl chloride quaternary salt), a tertiary salt and / or a quaternary salt of dimethylaminoethyl (meth) acrylate (for example, methyl chloride quaternary salt). Examples thereof include molecular organic flocculants.

  In the present embodiment, water containing a hardly decomposable organic substance of 1500 mg / L or more, particularly 5000 mg / L or more is a treatment target. The hard-to-decompose organic substance-containing water is discharged from, for example, chemical factories, electronic machine component factories, building material factories, paint factories, and the like. Here, the hard-to-decompose organic substance means an organic substance that is difficult to be decomposed by a biological treatment method usually used in wastewater treatment and can increase COD in a solution. For example, as a raw material for a lubricant or the like Polyethylene glycol (PEG) used, Polypropylene glycol (PPG) used as a raw material for polyurethane, etc. Polyvinyl alcohol (PVA) used as a raw material for vinylon, film, etc. Used as a raw material for molded products, films, etc. Polypropylene, further polyethylene, aromatics, nitro compounds, chloro compounds, and poxyethylene surfactants used as a raw material for surfactants are used as raw materials for films and various molded articles.

  Usually, when the concentration of the hardly decomposable organic substance in the target water reaches a level of 1500 mg / L or more, particularly 5000 mg / L or more, in the Fenton treatment (oxidation treatment) of the hardly decomposable organic substance, Since a large amount of COD derived from oxidative decomposition products remains, it is necessary to install a plurality of treatment facilities such as biological treatment and activated carbon treatment in the subsequent stage of the reaction tank. For this reason, it has been considered difficult to apply the Fenton treatment (oxidation treatment) alone in a high-concentration hardly-decomposable organic substance-containing water. However, the present inventors have found that it is difficult to apply such a Fenton treatment (oxidation treatment), and the treatment method of the present embodiment described below reduces the COD concentration against high-concentration hardly-decomposable organic substance-containing water. Found to be effective. In particular, polyvinyl alcohol is contained in a high concentration in various factory effluents and the like, is difficult to oxidatively decompose, and a large amount of COD tends to remain, but even for the treatment of such a high concentration of polyvinyl alcohol-containing water, The processing method of this embodiment is effective for reducing the COD concentration.

  Below, based on operation | movement of the processing apparatus 1 shown in FIG. 1, the processing method of highly concentrated hardly decomposable organic substance containing water is demonstrated.

<Oxidation process>
High concentration hardly decomposed organic substance-containing water (for example, PVA-containing water) as described above is supplied from the inflow line 10 to the oxidation treatment reaction tank 12. Further, the hydrogen peroxide in the hydrogen peroxide storage tank 14 is supplied from the hydrogen peroxide addition line 16 to the oxidation treatment reaction tank 12, and the iron compound (ferrous sulfate) in the iron compound storage tank 18 is iron. It is supplied from the compound addition line 20 to the oxidation treatment reaction tank 12. In the oxidation treatment reaction tank 12, so-called Fenton treatment is performed in which a hardly decomposable organic substance is oxidized and decomposed by hydroxy radicals generated by the reaction between hydrogen peroxide and iron ions of an iron compound. At this time, decomposition products, organic acids, and the like that have been reduced in molecular weight are generated and are included as COD in the treated water after the oxidation treatment.

  In the present embodiment, the amount of hydrogen peroxide supplied to the oxidation treatment reaction tank 12 is preferably set to a molar ratio of 1 or more with respect to COD in the hardly-decomposable organic substance-containing water, and is preferably 2 or more moles. The ratio is more preferable. Moreover, it is preferable that the density | concentration of the iron compound supplied to the oxidation treatment reaction tank 12 shall be 500 mg / L or more, and it is more preferable to set it as 1000 mg / L or more. Moreover, it is preferable that pH at the time of carrying out the oxidative decomposition of a hardly decomposable organic substance is adjusted to the range of 2-4.

  As for the method of adding hydrogen peroxide, the required amount may be added at once. However, if it is added at once, even if hydroxyl radical, which is a strong oxidizing agent, is generated, the radicals are consumed and hardly decomposed. Since the organic matter may not be decomposed efficiently, the necessary amount is preferably added continuously over 30 minutes, preferably about 1 hour.

  The addition ratio of hydrogen peroxide to iron in the iron compound is preferably high in hydrogen peroxide, but if it is too large, the consumption of oxidants may increase, so that the molar ratio is 1: 1-5. : 1 range is preferred, and a range of 1: 1 to 2: 1 is more preferred.

  Although the reaction time of the oxidation treatment is not particularly limited, for example, a range of 5 minutes to 4 hours is preferable, and a range of 15 minutes to 2 hours is more preferable.

<Slaked lime addition process>
Next, the slaked lime in the slaked lime storage tank 22 is supplied from the slaked lime addition line 24 into the oxidation treatment reaction tank 12 and added and mixed with the treated water after the oxidation treatment. As described above, COD remains in the treated water after the oxidation treatment. In particular, high-concentration COD remains in the treated water after oxidation treatment of a high-concentration hardly decomposable organic substance of 1500 mg / L or more. However, as in this embodiment, by adding slaked lime to the treated water after the oxidation treatment, the COD concentration in the treated water can be efficiently reduced. As a result, it is possible to reduce treatment facilities such as biological treatment and activated carbon treatment after the oxidation treatment reaction tank 12. Although the reduction mechanism of the COD concentration by the addition of slaked lime is unknown, it is considered that the calcium in the slaked lime binds or adsorbs to the COD derived from the oxidative decomposition product and contributes to the reduction of the COD concentration.

  In the present embodiment, the oxidation treatment reaction tank may be multi-staged. However, since the COD concentration can be efficiently reduced only by adding slaked lime, a single oxidation treatment reaction tank can be obtained. A single oxidation treatment reactor can be said to be very practical from an economical and space perspective.

  The pH of the treated water after the oxidation treatment is 7 to 11 by adding slaked lime or the like from the viewpoint of efficiently reducing the COD concentration or improving the cohesiveness in the subsequent addition of the polymer flocculant. The neutral side is preferably adjusted to the alkali side, and more preferably 9 to 11 side.

<Solid-liquid separation process>
Next, the polymer flocculant in the flocculant storage tank 26 is supplied from the flocculant addition line 28 into the oxidation treatment reaction tank 12 and added and mixed with the calcium salt-containing treated water after the addition of slaked lime. At this time, the treated water is stirred at a high speed and slowly by the stirring device 32 such as a stirring blade to grow flocs in the treated water. And after stirring for a predetermined time, stirring is stopped, flocs are settled, and solid-liquid separation is carried out into sludge containing flocs and supernatant water (final treated water). Final treated water is discharged from the discharge line 30a to the outside of the system, and sludge containing floc is discharged from the discharge line 30b to the outside of the system. The final treated water is desirably discharged after neutralizing the pH by adding a pH adjuster or mixing with other waste water as necessary.

  FIG. 2 is a schematic diagram illustrating another example of the configuration of the treatment apparatus for water containing hardly decomposed organic matter according to the present embodiment. The processing apparatus 2 shown in FIG. 2 is a continuous processing apparatus, and includes an inflow line 10, an oxidation treatment reaction tank 12, a hydrogen peroxide storage tank 14 containing hydrogen peroxide, and hydrogen peroxide addition as a hydrogen peroxide addition means. Line 16, iron compound storage tank 18 containing iron compounds, iron compound addition line 20 as iron compound addition means, slaked lime reaction tank 36, slaked lime storage tank 22 containing slaked lime, slaked lime addition line 24 as slaked lime addition means, A coagulation reaction tank 38, a coagulant storage tank 26 for storing the polymer coagulant, a coagulant addition line 28 as a coagulant addition means, a precipitation tank 40, and discharge lines 30a and 30b are provided. Each reaction tank is desirably provided with a stirring device 32 such as a stirring blade, and the oxidation treatment reaction tank 12 and the slaked lime reaction tank 36 are preferably provided with a pH meter 34 or the like. It is desirable to install a pump for adjusting the flow rate of each drug in the hydrogen peroxide addition line 16, the iron compound addition line 20, the slaked lime addition line 24, the flocculant addition line 28, and the like.

  As shown in FIG. 2, an inflow line 10 is connected to the oxidation treatment reaction tank 12. One end of the hydrogen peroxide addition line 16 is connected to the hydrogen peroxide storage tank 14, and the other end is connected to the oxidation treatment reaction tank 12. One end of the iron compound addition line 20 is connected to the iron compound storage tank 18, and the other end is connected to the oxidation treatment reaction tank 12. One end of the slaked lime addition line 24 is connected to the slaked lime storage tank 22, and the other end is connected to the slaked lime reaction tank 36. Further, one end of the flocculant addition line 28 is connected to the flocculant storage tank 26, and the other end is connected to the aggregation reaction tank 38. In addition, the respective layers are connected by pipes 42 a and 42 b (the pipe between the slaked lime reaction tank 36 and the agglomeration reaction tank 38 is omitted), and discharge lines 30 a and 30 b are connected to the precipitation tank 40.

  Below, operation | movement of the processing apparatus 2 shown in FIG. 2 is demonstrated.

<Oxidation process>
High concentration hardly decomposed organic substance-containing water (for example, PVA-containing water) as described above is supplied from the inflow line 10 to the oxidation treatment reaction tank 12. Further, the hydrogen peroxide in the hydrogen peroxide storage tank 14 is supplied from the hydrogen peroxide addition line 16 to the oxidation treatment reaction tank 12, and the iron compound (ferrous sulfate) in the iron compound storage tank 18 is iron. It is supplied from the compound addition line 20 to the oxidation treatment reaction tank 12. In the oxidation treatment reaction tank 12, so-called Fenton treatment is performed in which a hardly decomposable organic substance is oxidized and decomposed by hydroxy radicals generated by the reaction between hydrogen peroxide and iron ions of an iron compound. At this time, decomposition products, organic acids, and the like that have been reduced in molecular weight are generated and are included as COD in the treated water after the oxidation treatment. The processing conditions such as the hydrogen peroxide concentration in the oxidation processing step are the same as those in the batch processing apparatus described above.

<Slaked lime addition process>
Next, the treated water after the oxidation treatment is supplied to the slaked lime reaction tank 36 through the pipe 42a, and the slaked lime in the slaked lime storage tank 22 is supplied from the slaked lime addition line 24 to the slaked lime reaction tank 36, and after the oxidation treatment. Added to the treated water. Thus, by adding slaked lime to the treated water after the oxidation treatment, the COD concentration in the treated water can be efficiently reduced. As a result, it is possible to reduce a plurality of treatment facilities such as biological treatment and activated carbon treatment after the oxidation treatment reaction tank 12. The treatment conditions such as the pH of the treated water after the oxidation treatment are the same as those of the batch type treatment apparatus described above (add them if they are different).

<Solid-liquid separation process>
Next, the calcium salt-containing treated water after the addition of slaked lime is supplied to the coagulation reaction tank 38 through a pipe (not shown), and the polymer coagulant in the coagulant storage tank 26 is fed from the coagulant addition line 28. It is supplied into the agglomeration reaction tank 38 and added and mixed with the calcium salt-containing treated water after the addition of slaked lime. At this time, the treated water is stirred at a high speed and slowly by the stirring device 32 such as a stirring blade to grow flocs in the treated water. And after stirring for the predetermined time, the treated water containing a floc is supplied to the sedimentation tank 40 through the piping 42b. In the sedimentation tank 40, solid sludge is separated into sludge containing floc and supernatant water (final treated water), and the final treated water is discharged out of the system from the discharge line 30a, and the sludge containing floc is discharged from the discharge line 30b to the system. It is discharged outside. The final treated water is desirably discharged after neutralizing the pH by adding a pH adjuster or mixing with other waste water as necessary.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail more concretely, this invention is not limited to a following example.

Example 1
1, 800 mL of raw aqueous PVA-containing water (actual waste water from a factory) shown in Table 1 was treated under the following conditions. PVA was quantified by the iodine colorimetric method. The TOC was quantified by a combustion oxidation-infrared TOC automatic measurement method (JIS K0102 22.2) using a TOC meter (manufactured by Shimadzu Corporation). COD was quantified by oxygen consumption by potassium permanganate at 100 ° C. (JIS K0102217).

(Processing conditions)
Add ferrous sulfate to the oxidation treatment tank to 500 mg / L, and add 30% hydrogen peroxide continuously over 1 hour to 20000 mg / L at a flow rate of 1 mL / min. did. After completion of the addition, the mixture was stirred for 1 hour at a stirring speed of 150 rpm to carry out an oxidation treatment reaction. After the oxidation treatment reaction, slaked lime (calcium hydroxide) was added to adjust the pH of the treated water after the oxidation treatment to 10, followed by stirring at a stirring speed of 150 rpm for 10 minutes. 10 mg / L of a polymer flocculant (Olflock AP-1, manufactured by Organo Corporation) was added to the calcium salt-containing treated water after the addition of slaked lime, and the mixture was stirred for 1 minute at a stirring speed of 150 rpm and 5 minutes at a stirring speed of 40 rpm. . After the stirring was stopped, the treated water was allowed to stand for 10 minutes in the oxidation treatment reaction vessel and subjected to solid-liquid separation, and then supernatant water was obtained as the final treated water.

(Example 2)
Example 1 except that ferrous sulfate was added to 5000 mg / L and 30% hydrogen peroxide was continuously added to 40000 mg / L at a flow rate of 1 mL / min over 1 hour. The same processing conditions were used.

(Comparative Example 1)
The processing conditions were the same as in Example 1 except that slaked lime was replaced with caustic soda.

(Comparative Example 2)
The processing conditions were the same as in Example 2 except that slaked lime was replaced with caustic soda.

(Comparative Example 3)
The treatment conditions were the same as in Example 1 except that no hydrogen peroxide was added.

  PVA, TOC, and COD in the final treated water of Examples 1-2 and Comparative Examples 1-3 were quantified by the same method as described above. The results are summarized in Table 2.

  In Example 1 and Comparative Example 1, the hydrogen peroxide and the iron concentration were subjected to the oxidation reaction under the same conditions, but the TOC concentration and COD concentration of Example 1 to which slaked lime was added were the TOC of Comparative Example 1 to which caustic soda was added. The value was about 1/3 of the concentration and COD concentration, showing a remarkably low value. Furthermore, in Example 2 in which the hydrogen peroxide concentration and the iron salt concentration were increased, both the TOC concentration and the COD concentration could be reduced to 100 mg / L or less. In contrast, Comparative Example 2 in which the hydrogen peroxide and iron concentrations were subjected to an oxidation reaction under the same conditions had a TOC concentration of 1900 mg / L and a COD concentration of 1400 mg / L, which are very high values compared to Example 2. became. In addition, since it cannot discharge with the treated water of the comparative example 2, the facilities, such as a biological treatment and an activated carbon treatment, are required in a back | latter stage.

  In Comparative Example 3, the effect of only adding slaked lime (calcium hydroxide) other than the oxidation treatment was examined by oxidizing the hydrogen peroxide solution without addition. As a result, the removal rate of all of PVA, TOC, and COD was low. That is, it was confirmed that PVA cannot be decomposed in the first place by the treatment using calcium hydroxide and iron. Moreover, as can be seen from the results of Example 1 and Example 2, the example in which the Fenton treatment and calcium hydroxide were combined had a higher synergistic effect than the conventional Fenton treatment or calcium hydroxide single treatment.

  1, 2 treatment apparatus, 10 inflow line, 12 oxidation treatment reaction tank, 14 hydrogen peroxide storage tank, 16 hydrogen peroxide addition line, 18 iron compound storage tank, 20 iron compound addition line, 22 slaked lime storage tank, 24 slaked lime addition Line, 26 Coagulant storage tank, 28 Coagulant addition line, 30a, 30b Discharge line, 32 Stirrer, 34 pH meter, 36 Slaked lime reaction tank, 38 Coagulation reaction tank, 40 Precipitation tank, 42a, 42b Piping.

<Slaked lime addition process>
Next, the treated water after the oxidation treatment is supplied to the slaked lime reaction tank 36 through the pipe 42a, and the slaked lime in the slaked lime storage tank 22 is supplied from the slaked lime addition line 24 to the slaked lime reaction tank 36, and after the oxidation treatment. Added to the treated water. Thus, by adding slaked lime to the treated water after the oxidation treatment, the COD concentration in the treated water can be efficiently reduced. As a result, it is possible to reduce a plurality of treatment facilities such as biological treatment and activated carbon treatment after the oxidation treatment reaction tank 12. In addition, processing conditions, such as pH of the treated water after an oxidation process, are the same as that of the above-mentioned batch type processing apparatus .

Claims (8)

An oxidation treatment step in which an iron compound and hydrogen peroxide are added to water containing 1500 mg / L or more of a hardly decomposable organic substance-containing water, and an oxidation treatment step;
And a slaked lime addition step of adding slaked lime to the treated water subjected to the oxidation treatment.   The method for treating hardly-decomposable organic substance-containing water according to claim 1, wherein the hardly-decomposable organic substance-containing water is polyvinyl alcohol-containing water.   The method for treating hardly-decomposable organic substance-containing water according to claim 1, wherein the iron compound contains ferrous sulfate.   The method for treating hardly-decomposable organic substance-containing water according to any one of claims 1 to 3, wherein the oxidation treatment is performed in a single reaction tank. An oxidation treatment means for performing an oxidation treatment by adding an iron compound and hydrogen peroxide to water containing a hardly decomposable organic substance of 1500 mg / L or more;
A treatment apparatus for water containing hardly decomposable organic matter, comprising: slaked lime addition for adding slaked lime to treated water subjected to the oxidation treatment.   6. The processing apparatus for water containing hardly decomposable organic substance according to claim 5, wherein the water containing hardly decomposable organic substance is water containing polyvinyl alcohol.   The apparatus for treating hardly-decomposable organic substance-containing water according to claim 5 or 6, wherein the iron compound contains ferrous sulfate.   The said oxidation treatment means is a single reaction tank, The processing apparatus of the hardly decomposable organic substance containing water of any one of Claims 5-7 characterized by the above-mentioned.

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