JP5557230B2 - Method for treating estrogen-containing water - Google Patents

Description

  The present invention relates to a method for treating estrogen-containing water. That is, the present invention relates to a treatment method for oxidizing and decomposing estrogen contained in water to be treated such as waste water based on the Fenton method.

《Technical background》
Estrogens are known as female and estrus hormones that are typically secreted from female ovaries. And estrogen derived from humans such as estradiol, estrone and estriol is typical, but natural estrogen derived from other livestock and synthesized artificial estrogen such as pill are also in its category.
Well, estrogen is excreted out of the body as urine, etc., but sewage and wastewater, river water, lake water, groundwater, sewage treatment plant inflow water, sewage treatment plant discharge water, water treatment plant intake water, etc. Recently, its residue, contamination and detection have been reported one after another.
In such an aqueous system, there is a concern about the feminization phenomenon of organisms, such as the confirmation of the feminization phenomenon of fish. That is, estrogen, particularly estradiol, which has a strong biological activity, is in a situation where there are concerns about adverse effects on the human body, ecosystem, environment, etc. along with so-called endocrine disruptors.

<Conventional technology>
On the other hand, effective treatment technology and purification technology have not been established yet. The need for processing estrogen contained in sewage, wastewater, and other water systems is expected to increase in the future, but due to the persistent nature of the polymer organic structure, efficient processing technology is not available. Not yet established. As this kind of estrogen treatment technology, only the following technology can be grasped.
In other words, activated sludge treatment method, other microbial treatment methods (typical as sewage treatment plant equipment), combustion method, other heat treatment methods, oxidative decomposition method by hydrogen peroxide and radiation irradiation, treatment as industrial waste Laws, etc. are only proposed. A Fenton method has also been proposed in which OH radicals are generated with hydrogen peroxide and an iron salt to oxidatively decompose estrogen.

《Information on prior art documents》
The following Patent Documents 1 and 2 relate to a microorganism treatment method, and Patent Document 3 relates to a heat treatment method.
JP 2007-769 A JP 2004-154682 A JP 2004-34008 A

About the problem
By the way, the following problems have been pointed out for this type of conventional example.
First, regarding the microbial treatment method, heat treatment method, oxidative decomposition method, etc., firstly, problems have been pointed out in the certainty of treatment and treatment performance, and the estrogen treatment rate, degradation rate, and removal rate were low. In addition, with large-scale equipment and enormous energy consumption, problems have been pointed out in terms of initial cost and running cost, as well as control complexity and processing stability. As is well known, the industrial waste treatment method has a high cost for transportation and treatment, and has a problem in initial cost.
With respect to the conventional Fenton method, problems have been pointed out in terms of processing performance and running cost (chemical use cost). For example, hydrogen peroxide is easily decomposed into water and oxygen during the treatment, and the generation efficiency of OH radicals is poor, and a large amount of hydrogen peroxide is excessively added to cover this. The post-processing cost by the agent was also increased.

<< About the present invention >>
The treatment method for estrogen-containing water of the present invention has been made in order to solve the above-described problems of the conventional examples in view of such circumstances.
According to the present invention, firstly, a large amount of OH radicals can be efficiently generated, so that estrogen can be reliably oxidized and decomposed, and secondly, it has running costs, post-processing costs, and control. The purpose is to propose a method for treating estrogen-containing water, which is realized with excellent ease of treatment, stability of treatment, initial cost, and the like.

<About Claim>
The technical means of the present invention for solving such a problem is as follows.
The method for treating estrogen-containing water according to claim 1 oxidizes and decomposes estrogen contained in the water to be treated based on the treatment process of the Fenton method.
The estrogen is composed of an organic compound having a steroid skeleton having a hormonal action. Then, hydrogen peroxide, a divalent iron ion solution, and a pH adjuster are added to the water to be treated containing the estrogen.

Then, the entire amount of hydrogen peroxide is added to the treatment tank at the beginning of the reaction.
In the treatment tank, divalent iron ions are intermittently added repeatedly in a plurality of cycles after the addition of hydrogen peroxide, so that the OH radicals generated below return to water and are wasted. It works to avoid.
As for the pH adjuster, an acid pH adjuster is first added to the water to be treated supplied to the treatment tank in the pH adjustment tank, and divalent iron is added in the treatment tank after the addition of hydrogen peroxide. Since pH decreases and acidity increases excessively at every ion addition, an alkaline pH adjuster is added each time.
Therefore, the pH adjuster constantly maintains the water to be treated at a weak acidity of pH 3 to pH 5 to promote the electron donating function of divalent iron ions to hydrogen peroxide, and hydrogen peroxide is decomposed into water and oxygen. , Function to suppress wasted reactions.

The amount of hydrogen peroxide and divalent iron ions added is calculated based on the theoretical reaction value based on the reaction formula.
First, from the specific content of estrogen contained in the water to be treated, the number of moles of the theoretical reaction value of OH radical is obtained as a standard, and then the actual required number of moles of OH radical is larger than this standard. Further calculated from the required number of moles of OH radicals, the theoretical number of moles of reaction of hydrogen peroxide and divalent iron ions, which are OH radical products, is obtained as a reference, and peroxidation The required number of moles of hydrogen and divalent iron ions that are actually prepared is calculated from this criterion.
The addition timing of hydrogen peroxide and divalent iron ions is when hydrogen peroxide is used up and hydrogen peroxide is exhausted from the water to be treated in the treatment tank. This is a time when divalent iron ions disappear from the water to be treated in the treatment tank after the previously added portion is used up.

As for the OH radical production reaction, hydrogen peroxide is reduced with divalent iron ions each time it is added in a divided manner, and in addition to the Fenton main reaction, in which OH radicals are produced, the hydrogen peroxide is further reduced. The generated hydroxide ions are oxidized by trivalent iron ions generated by the oxidation reaction of divalent iron ions to generate OH radicals, and the generated OH radicals are further covered. The reaction of reacting with the water of the treated water to generate new OH radicals and water is repeated in a chain, and the trivalent iron ions and peroxidation produced by the oxidation reaction of the divalent iron ions. The reaction of reacting with hydrogen to generate at least new OH radicals is repeated in a chain, and the water to be treated is weak in both the main reaction and the incidental, secondary and chained three reactions. Maintain an acidic atmosphere When the hydrogen peroxide is exhausted in the treatment tank, the generation of OH radicals is completed.
Thus, the estrogen contained in the water to be treated is oxidized and decomposed by the OH radicals thus generated, and is mineralized into a low molecular weight compound of water, oxygen, and carbon dioxide.

<About the action>
Since the present invention comprises such means, the following is achieved.
(1) The water to be treated containing estrogen such as estradiol, estrone, estriol is supplied to the treatment apparatus, and thus the estrogen is oxidized and decomposed by the treatment method based on the Fenton method.
(2) The treatment apparatus includes a water to be treated supply means, a treatment tank, a post-treatment tank, and the like. The treatment tank is provided with hydrogen peroxide addition means, iron ion addition means, pH adjustment means, and the like.
(3) And the water to be treated is supplied to the treatment tank, but before that, sulfuric acid or the like is added from the pH adjusting means to make it weakly acidic at about pH 4.
(4) In the treatment tank, all the hydrogen peroxide is first added from the hydrogen peroxide addition means to the treated water supplied.
(5) Then, a divalent iron ion solution is dividedly added from the iron ion adding means, and for each divided addition, caustic soda or the like is added from the pH adjusting means, and the weak acidity of the water to be treated is maintained. .
(6) In the treatment tank, first, hydrogen peroxide generates OH radicals using divalent iron ions as a catalyst. In this production reaction, iron ions are dividedly added, so that there is no possibility of a reaction that wastes OH radicals and iron ions. In addition, since the atmosphere is weakly acidic, the catalytic function of iron ions is promoted, so that hydrogen peroxide is not decomposed or wasted into water and oxygen.
(7) Secondly, OH radicals can also be generated by the reaction of trivalent iron ions and hydroxide ions generated by the above reaction.
(8) Thirdly, OH radicals can be obtained by reacting OH radicals generated by the above reaction with water such as water to be treated, and fourthly, trivalent iron ions generated by the above reaction. Also, hydrogen peroxide reacts with each other to generate new ones in a chain.
(9) In the treatment tank, a large amount of OH radicals are efficiently generated by such a chain reaction. The estrogen contained in the water to be treated is surely oxidized and decomposed by the strong oxidizing power of the OH radicals generated in this way, so that it becomes mineralized into low molecular weight compounds such as water, oxygen and carbon dioxide. Is done.
(10) The treated water is treated as described above, and then drained outside through the treatment tank.
(11) In this processing method, the addition amount of the Fenton reagent and the like can be easily calculated from the theoretical reaction value, the configuration is relatively simple, and stable processing is easily possible.
(12) Now, the treatment method of the present invention exhibits the following effects.

<< First effect >>
First, OH radicals are efficiently produced in large quantities, so that estrogens can be reliably oxidized and decomposed.
That is, in the processing method of the present invention, first, a. OH radicals are efficiently generated by maintaining the weak acidity of the water to be treated, adding all of the hydrogen peroxide, split addition of divalent iron ions, and the like. And b. The OH radical repeats in a chain by the reaction of trivalent iron ions and hydroxide ions, the reaction of the generated OH radicals with water, the reaction of trivalent iron ions with hydrogen peroxide, etc. Produced in large quantities with high efficiency.
With these a and b, in the present invention, the oestrogen such as estradiol mixed and contained in the water to be treated such as waste water by the OH radical generated in a large amount by the chain reaction is ensured under high treatment performance. Oxidized, decomposed and removed. The treated water is surely purified and detoxified.

<< Second effect >>
Secondly, such oxidation and decomposition of estrogen is realized with excellent running cost, post-processing cost, ease of control, stability of processing, initial cost, and the like.
That is, in the processing method of the present invention, first, a. Like the Fenton method of this type, the hydrogen peroxide is not decomposed and wasted into water and oxygen, and it is not necessary to add an excessive amount of hydrogen peroxide. Cost and running cost are reduced.
b. Like this conventional Fenton method, hydrogen peroxide is not added excessively, the water to be treated after treatment has a small residual content of hydrogen peroxide, and the post-treatment cost by the neutralizing agent is also reduced. .
c. The amount of hydrogen peroxide added corresponding to the content of estrogen, the amount of divalent iron ions added corresponding to the amount of hydrogen peroxide added, the amount of pH adjuster added, etc. can be easily calculated from theoretical reaction values. And the required number of moles is obtained. Therefore, it is easy to control the addition of an appropriate amount of chemicals without excess and deficiency, and automatic control is possible. For example, there is no situation where divalent iron ions remain or run short, and the processing is stabilized. .
d. Compared to the above-described conventional treatments (microorganism treatment method, heat treatment method, oxidative decomposition method, etc.), the configuration is simple and easy. From this aspect, the treatment stability is excellent and the initial cost such as equipment cost, Running costs such as energy consumption costs and other various costs are also reduced. Of course, the same applies to the industrial waste treatment method.
The processing method of the present invention opens the way to practical application, that is, scale-up application to full-scale processing, large-scale processing, large-capacity processing, and the like, from each of a, b, c, and d. For example, by performing the treatment method of the present invention, it becomes possible to easily purify sewage and wastewater containing estrogen such as estradiol.
As described above, the effects exerted by the present invention are remarkably large, such as all the problems existing in this type of conventional example are solved.

《About drawing》
Hereinafter, the method for treating estrogen-containing water of the present invention will be described in detail based on the best mode for carrying out the invention shown in the drawings.
FIG. 1 is a configuration flowchart for explaining the best mode for carrying out the present invention.

About estrogen 1
First, estrogen 1 which is a processing target of the processing method of the present invention will be described.
Estrogen 1 is composed of an organic compound having a steroid skeleton having a hormonal action, and is typically estradiol, estrone, estriol, and the like.
It is secreted from female ovaries, etc., and acts as a female hormone and estrus hormone, but the waste is excreted from the body as urine, etc., and may remain, be mixed, or contained in sewage, wastewater, or other water systems. is there.

Such estrogen 1 will be further described in detail. Estrogens are defined as a general term for natural or synthetic substances that biologically have female hormone action, estrus hormone action, and follicular (follicular) hormone action.
And it is secreted mainly from the ovary (produced by follicular cells of vertebrates, that is, mammalian ovaries), but is also secreted by the adrenal gland and others. Of course, it is secreted not only by humans but also by domestic animals and other animals, and most of them are derived from human animals. include.
And estrogen 1 is composed of an organic compound having a high molecular structure having a steroid type skeleton having a hormonal action. That is, it consists of a steroid skeleton in which a phenanthrene-type organic structure consisting of three carbon six-atom rings, ie, six-membered rings (including aromatic rings), is attached with one carbon five-atom ring, ie, a five-membered ring.

The specific contents of estrogen 1 are listed as follows.
Estradiol _{(E2) (ESTRADIOL, C 18} H 24 O 2)
-Specifically, there are α and β stereoisomers, and there are active 17β-estradiol and 17α ethinyl esladiol.
・ Estron (E1) (ESTRON, C ₁₈ H ₂₂ O ₂ )
・ Estriol (E3) (ESTRIOL, C ₁₈ H ₂₄ O ₃ )
・ Ekiline, echilenin, metabolites of these ・ Homoestrone, dwazinol, etc. which are chemical derivatives In addition, estradiol has the strongest biological activity, which is about 5 to 10 times that of estrone and 10 to 100 times that of estriol. ing. It can be said that estradiol is the substance with the greatest concern about adverse effects on the human body, ecosystem, and environment.
The present invention treats estrogen 1 contained in sewage, waste water, or other water-based treated water 3.

<Outline of processing method>
The treatment method of the present invention oxidizes and decomposes estrogen 1 contained in the water to be treated 3 based on the improved Fenton treatment process.
That is, in the treatment method of the present invention, the water containing estrogen 1 is treated water 3. Then, the contained estrogen 1 is converted to OH radicals (.OH) generated by the Fenton main reaction using hydrogen peroxide (H ₂ O ₂ ) and divalent iron ions (Fe ²⁺ ) of the Fenton reagent, It is oxidized and decomposed by OH radicals generated by incidental, secondary, and chain reactions of the Fenton main reaction, and mineralized into water, carbon dioxide, and other low-molecular compounds.
The present invention includes a treatment tank 4, a treated water supply means 5, a hydrogen peroxide addition means 6, an iron ion addition means 7, and a pH adjustment means 8 attached to the treatment tank 4. Hereinafter, these will be described in detail.

<< About treated water supply means 5 etc. >>
First, the treated water supply means 5 and the like will be described. The treated water supply means 5 supplies the treated water 3 containing estrogen 1 to the treatment tank 4 as a treatment target.
That is, the treated water 3 is introduced into the raw water tank 9 of the treated water supply means 5, and the treated water 3 is supplied to the treated tank 4 via the raw water tank 9 and the pH adjusting tank 10. The The treated water 3 introduced into the raw water tank 9 is subjected to pretreatment such as dust sludge removal and biological treatment in advance as necessary. In the pH adjusting tank 10, a pH adjusting agent is added from the attached pH adjusting means 8.
The pH adjusting means 8 adds a pH adjusting agent to the treated water 3 being supplied from the raw water tank 9 of the treated water supply means 5 to the treated tank 4 so as to reduce the treated water 3 to a predetermined weakness. After adjusting to acidity, it is supplied to the treatment tank 4. That is, the treated water 3 from the raw water tank 9 is often pH 6 or more, for example, so that the pH is adjusted to about pH 5 to about 3, typically about pH 4, so that an acid pH such as sulfuric acid is used as a pH adjuster. A modifier is used.
The reason for adjusting the pH in advance in this way is that, as will be described later, in order to ensure that the OH radical production reaction with hydrogen peroxide and divalent iron ions is performed efficiently as expected. is there. In addition, the said pH adjustment tank 10 is used in the case of the large volume process of the to-be-processed water 3, a continuous process, the process of the high concentration estrogen 1, etc., for example.
The treated water supply means 5 and the like are as described above.

<About hydrogen peroxide addition means 6>
Next, the hydrogen peroxide addition means 6 attached to the processing tank 4 will be described. The hydrogen peroxide addition means 6 adds a total amount of an aqueous solution of hydrogen peroxide (H ₂ O ₂ ) to the treated water 3 in the treatment tank 4 as a Fenton reagent at the beginning of the reaction. Hydrogen peroxide is a source of OH radicals.
The amount of hydrogen peroxide added per reaction depends on the specific content and concentration of the estrogen 1 to be treated contained in the water 3 to be treated. The actual required amount (necessary number of moles) calculated in (1) is added all at once at the beginning of the reaction. The next addition is when hydrogen peroxide is exhausted from the water 3 to be treated in the treatment tank 4, that is, at the next reaction, and the whole amount is added in the same manner. In this specification, the addition of the total amount means that 100% of the amount of the drug necessary for the reaction is added all at once.
In this way, the entire amount of hydrogen peroxide is added from the hydrogen peroxide addition means 6.

<< About iron ion addition means 7 >>
Next, the iron ion addition means 7 attached to the processing tank 4 will be described. The iron ion adding means 7 intermittently repeats a plurality of cycles with respect to the water to be treated 3 of the treatment tank 4 after the addition of hydrogen peroxide as described above, thereby supplying a divalent iron ion (Fe ²⁺ ) solution to Fenton. Add in portions as reagents.
That is, substances that generate divalent iron ions in the liquid, such as ferrous sulfate heptahydrate (FeSO ₄ · 7H ₂ O), are typically used as such iron salts, but other anhydrous Salts and hydrated salts such as iron chloride (FeCl ₂ ) and hydrates thereof can also be used. The divalent iron ion functions as a catalyst for the OH radical generation reaction of hydrogen peroxide. The amount of iron ion added per reaction is calculated based on the theoretical reaction value, but a larger actual required amount is, for example, about 0.5 mol per 1 mol of hydrogen peroxide.
Moreover, this iron ion is divided and added in multiple times. That is, the necessary amount for one reaction is not added in the whole amount, but is divided into about 3 to 7 times, for example, 5 times, and is added sequentially. As for the addition timing for each time, the next time is added at the stage where the previous addition is gone. Thus, in this specification, divided addition means that the amount of drug necessary for the reaction is added in multiple portions.
The reason why the divalent iron ions are added separately is as follows: a, b, c. First a. If the total amount is added, in the chemical reaction to be described later, the OH radical is wasted at the same time as the intended positive reaction from the original system using hydrogen peroxide as a reactant to the production system using OH radical as a product. Reaction is likely to occur. That is, a reaction in which surplus OH radicals return to water easily occurs, loss occurs, and iron ions used for generating OH radicals are wasted. On the other hand, when the addition is divided, such a reaction is suppressed and the waste of iron ions is eliminated.
B. OH radicals have a very short reaction time due to their intense reaction, and have a very short life. When the total amount is added in a divided manner, OH radicals are generated each time, and the corner of the treated water 3 in the treatment tank 4 is generated. I will come across. As a result, the oxidation and decomposition of estrogen 1 are ensured, made efficient, and accelerated.
C. When the addition is divided, the remaining hydrogen peroxide is smaller than the total addition, and accordingly, the post-treatment cost by the neutralizing agent is reduced accordingly.
In this way, divalent iron ions and the like are dividedly added from the iron ion adding means 7.

<About pH adjusting means 8>
Next, the pH adjusting means 8 attached to the processing tank 4 will be described. The pH adjusting means 8 adjusts the pH of the water to be treated 3 before being supplied from the water to be treated supplying means 5 to the treatment tank 4 and the water to be treated 3 after being supplied to the treatment tank 4 as described above. An agent is added to maintain the water to be treated 3 at a weak acidity of about pH 4, for example.
That is, the pH adjusting means 8 adds an acid pH adjuster such as sulfuric acid (H ₂ SO ₄ ) before the addition of hydrogen peroxide, and after the addition of hydrogen peroxide, An alkaline pH adjuster such as caustic soda (NaOH) is added.
The reasons for maintaining the water to be treated 3 at about pH 3 to about pH 5 typically about pH 4 are as follows: a, b, c. a. As will be described later, it functions to suppress a wasteful decomposition reaction of hydrogen peroxide into water and oxygen that inhibits the intended reaction. b. It functions to promote electron donation of divalent iron ions to hydrogen peroxide. c. It functions to promote and ensure the incidental, secondary, and chain-repeated OH radical generation reactions described below. With these a, b, and c, generation of OH radicals proceeds efficiently.
On the other hand, first, the treated water 3 from the raw water tank 9 of the treated water supply means 5 is often, for example, pH 6 or higher, and therefore, as described above, in the pH adjusting tank 10, for example, from the pH adjusting means 8. Sulfuric acid is added to adjust the pH to about 4, for example. Then, after the fact, when divalent iron ions are added in the treatment tank 4, the pH of the water to be treated 3 is lowered to, for example, about 2.8 and the acidity is excessively increased. For each divided addition, for example, caustic soda is added to adjust the pH of the water to be treated 3 to about pH 4, for example.
The pH adjusting means 8 is as described above.

<< Reaction in Treatment Tank 4 (OH Radical Generation: Part 1) >>
Next, the chemical reaction (generation of OH radicals: part 1) in the treatment tank 4 will be described. In this treatment method, first, in the treatment tank 4, the water to be treated 3 is stirred and flowed down, and the added hydrogen peroxide is reduced with divalent iron ions added as a catalyst. OH radicals are generated.
The generation of such OH radicals will be further described in detail. In the treatment tank 4, OH radicals are generated based on the following chemical formulas 1 and 2 (chemical formula 3). This is the Fenton main reaction.

These will be further described in detail. In this Fenton main reaction, the divalent iron ions (Fe ²⁺ ) sequentially added from the iron ion addition means 7 in the reaction formula of the above chemical formula 1 maintain the treated water 3 in a weakly acidic atmosphere having a pH of about 4, for example. Therefore, as a catalyst, electrons (e ⁻ ) are sequentially donated to the hydrogen peroxide (H ₂ O ₂ ) of the above reaction formula 2 as a catalyst, and the self oxidizes to trivalent iron ions ( Fe ³⁺ ).
Therefore, in the reaction formula of Chemical Formula 2, all of the hydrogen peroxide initially added from the hydrogen peroxide addition means 6 is sequentially supplied with electrons based on the chemical formula of Chemical Formula 1, and in each case, OH radical (.OH) And hydroxide ions (OH ⁻ ) are produced. When the reaction formulas of Chemical Formula 1 and Chemical Formula 2 are synthesized together, the reaction formula of Chemical Formula 3 is obtained.
By the way, in such a reaction, since the to-be-processed water 3 is maintained in the weakly acidic atmosphere as mentioned above, it is suppressed that hydrogen peroxide is decomposed | disassembled into water and oxygen, and wasted. On the other hand, if it is not maintained in a weakly acidic atmosphere, hydrogen peroxide becomes water molecules (H ₂ O) while generating oxygen (O) in the nascent stage according to the following reaction formula 4; The reaction formula of Chemical Formula 2 (Chemical Formula 3) is wasted without generating OH radicals. It should be noted that oxygen in this nascent stage is out of the system as oxygen molecules (O ₂ ) when there is no oxidation target.
In the treatment tank 4, first, OH radicals are generated by such a Fenton main reaction.

<< Reaction in treatment tank 4 (generation of OH radicals: 2) >>
Next, the chemical reaction (generation of OH radical: part 2) in the treatment tank 4 will be described. Secondly, in the treatment tank 4, OH radicals (.OH) can be generated also by the following reaction formulas 5 and 6.
That is, in the treatment tank 4, first of all, OH radicals are generated by the Fenton main reaction in the reaction formula of the chemical formula 3 (Chemical formula 1, Chemical formula 2). OH radicals can also be generated incidentally, secondaryly, or chained by the reaction formula of ## STR5 ##

This will be further described in detail. In the treatment tank 4, the hydroxide ions (OH ⁻ ) generated by the reduction reaction of hydrogen peroxide are converted into trivalent iron ions (Fe ³⁺ ) generated by the oxidation reaction of divalent iron ions. Oxidized to generate OH radicals (.OH).
That is, the trivalent iron ion generated by the chemical formula 1 is converted into an electron (e ⁻ ) from the hydroxide ion generated by the chemical formula 2 according to the chemical formula 5 and chemical formula 6 above. OH radicals are generated, and they are reduced to divalent iron ions and returned. In this way, when not only the reaction formula of Chemical Formula 3 (Chemical Formula 1, Chemical Formula 2) but also the chemical formulas of Chemical Formula 5 and Chemical Formula 6 occur in a chain-balanced manner, OH radicals are generated more efficiently. The
Secondly, in the treatment tank 4, OH radicals can be generated by such a reaction.

<< Reaction in Treatment Tank 4 (Generation of OH radical: Part 3) >>
Next, the chemical reaction (generation of OH radicals: part 3) in the treatment tank 4 will be described. In the treatment tank 4, in addition to the first and second described above, new OH radicals are generated incidentally, secondary, and chained by the third reaction.
That is, the OH radicals generated in the reaction formulas of Chemical Formula 3 (Chemical Formula 1, Chemical Formula 2) and Chemical Formula 5 and Chemical Formula 6 react with water such as the water to be treated 3 to generate new OH radicals and water. The reaction to generate is repeated in a chained manner according to the following reaction formulas 7 and 8.

These will be further described in detail. First, in a neutral to alkaline atmosphere, OH radicals extract hydrogen atoms from water molecules and oxidize them to generate oxygen molecules, and are themselves reduced to water molecules.
On the other hand, in an acidic atmosphere, the OH radical (.OH) withdraws electrons (e ⁻ ) from water molecules (H ₂ O) according to the above reaction formula (7) and converts itself into hydroxide ions (OH ⁻ ). However, this abstraction reaction radically splits and activates water molecules to generate new OH radicals (.OH) and protons (H ⁺ ). The generated hydroxide ions and protons disappear by generating new water (H ₂ O) in the reaction formula of the above formula 8.
Since the water 3 to be treated in the treatment tank 4 is maintained in a weakly acidic atmosphere, new OH radicals are generated in this way. Further, based on the OH radicals thus generated, A series of reactions like this occur in a chain, and the subsequent process is repeated in a chain.
That is, once OH radicals are generated by the reaction formulas such as Chemical Formula 3, etc., OH radicals are obtained semipermanently by a chain reaction afterwards using this as an initiation reaction and reaction initiator. OH radicals, excluding the amount consumed in the process of oxidizing and decomposing estrogen 1, repeat generation and disappearance coexisting with proton chain formation and disappearance. Considering that the OH radical has a very short lifetime, the significance of such repeated generation is great.
Thirdly, in the treatment tank 4, OH radicals are also generated by such a reaction.

<< Reaction in Treatment Tank 4 (OH Radical Generation: Part 4) >>
Next, the chemical reaction (generation of OH radical: part 4) in the treatment tank 4 will be described. In the treatment tank 4, in addition to the first, second, and third described above, OH radicals are newly generated incidentally, subsidiaryly, and continuously by the following reaction.
That is, the reaction in which trivalent iron ions generated by the oxidation reaction of divalent iron ions react with hydrogen peroxide to newly generate OH radicals or the like is represented by the following chemical formulas 9 and 10. The reaction formula (reaction formula of Formula 11) is repeated in a chain.

These will be further described in detail. The trivalent iron ion (Fe ³⁺ ) generated by the reaction formula of Chemical Formula 3 (Chemical Formula 1) reacts with hydrogen peroxide (H ₂ O ₂ ) by the reaction formula of Chemical Formula 9 above. The iron ion is reduced to a divalent iron ion (Fe ²⁺ ), and a superoxide anion (.O ₂ ⁻ ), which is an ion generated by combining oxygen molecules with electrons, is generated.
Then, according to the reaction formula of the above chemical formula 10, this radical superoxide anion can react with hydrogen peroxide to generate an OH radical (.OH). When the reaction formulas of the chemical formulas 9 and 10 are synthesized together, the chemical formula of the chemical formula 11 is obtained.
Thus, as long as hydrogen peroxide that was the source of OH radical generation in the reaction formula of Chemical Formula 3 (Chemical Formula 2) remains (for example, in the process of oxidation and decomposition of estrogen 1, OH radicals are Even if it is consumed up, as long as surplus hydrogen peroxide remains, new OH radicals continue to be generated in a chain semipermanently based on the hydrogen peroxide) It will be. Considering that the OH radical has an extremely short lifetime, the significance of such generation continuation is great.
However, in order to ensure that the reaction formula of Chemical Formula 11 (Chemical Formula 9, Chemical Formula 10) occurs, even a weakly acidic atmosphere that does not decompose hydrogen peroxide into water and dissolved oxygen (see the chemical formula of Chemical Formula 4), A pH operation is required, such as adding caustic soda or the like to the water to be treated 3 of the treatment tank 4 by the pH adjusting means 8, and it is necessary to move the pH value to the alkali side.
Furthermore, although the divalent iron ion generated by the reaction formula of Chemical Formula 11 (Chemical Formula 9) lowers the pH, the necessary pH operation is performed in order to coexist with hydrogen peroxide that is stably present in the weakly acidic atmosphere as described above. If carried out, the generation of OH radicals can be expected by the Fenton main reaction of the reaction formula such as Chemical Formula 3 above.
In the treatment tank 3, fourthly, OH radicals are also generated by such a reaction.

<< Reaction in treatment tank 4 (oxidation and decomposition of estrogen 1) >>
Next, oxidation, decomposition and mineralization of estrogen 1 by OH radicals will be described. In this treatment method, in the treatment tank 4, the estrogen 1 contained in the water to be treated 3 is oxidized, decomposed and mineralized by the involvement of the OH radicals generated by the Fenton main reaction and others in this way. .
These will be described in more detail. The OH radical, that is, the hydroxy radical (.OH) has a strong oxidizing power as is well known. That is, it has an extremely strong electron (e ⁻ ) deprivation ability, oxidation ability, that is, activation ability and decomposition ability, which is unparalleled as an active oxygen species, and is highly reactive with radicals. In addition, since the reaction is intense, its existence time is a very short-lived chemical species.
Now, the OH radicals dispersed in the water phase oxidize the estrogen 1 contained in the water to be treated 3 and eventually decompose. The OH radical follows the chain process of oxidation and addition of the macromolecular organic structure of estrogen 1 and the organic structure of the intermediate of its decomposition process, so that the carbon chain, organic bond, and molecular bond are sequentially broken and decomposed. It is divided and finally oxidized, decomposed, and mineralized into inorganic low molecular weight compounds.

The basic theory of oxidation and decomposition by such OH radicals is as follows. That is, the following reaction is repeated for the organic structure of estrogen 1 to be treated and decomposed and intermediates of the decomposition process.
First, the OH radical deprives the hydrogen atom (H) of the hydroxyl group (—OH) to be decomposed and oxidizes, and returns itself to water (H ₂ O), and then converts the oxygen atom (O) of the hydroxyl group (—OH) into two. Double bond (= O).
Further, the OH radical oxidizes by depriving the hydrogen atom (H) of the hydrocarbon to be decomposed (oxygen-containing hydrocarbon, for example, terminal aldehyde group -CHO), and returns itself to water, and the carbon atom (C-) The OH radicals following the unpaired electrons are compatible. Thus, the hydroxyl group (-OH) is regenerated and the above-described reaction is repeated.
In the case where the OH radicals thus deplete the hydrogen atoms (H) to be decomposed and are oxidized, the following occurs. That is, the subsequent OH radical deprives the hydrogen molecule (H ₂ O) from the hydrogen atom (H) and oxidizes, and the OH radical itself returns to water, generating an oxygen molecule (O ₂ ) while generating the hydrogen radical (H ₂ O). ⁺ + E ⁻ ) is generated. And this hydrogen radical reduces and hydrogenates the decomposition | disassembly object from which the hydrogen atom (H) was exhausted. Thus, the hydrocarbon is regenerated and the above-described reaction is repeated.
Based on such a basic theory, the estrogen 1 to be treated and decomposed is oxidized, decomposed and mineralized into low molecular compounds such as water, oxygen and carbon dioxide.

<< About the post-treatment tank 11 >>
Next, the post-treatment tank 11 will be described. A post-treatment tank 11 is attached to the treatment tank 4 described above. And the to-be-processed water 3 after the estrogen 1 is oxidized and decomposed | disassembled by the above-mentioned to the post-processing tank 11 is discharged | emitted from the processing tank 4, a required process is performed, and it drains outside.
Such a post-treatment tank 11 will be further described in detail. The illustrated post-treatment tank 11 includes a neutralization tank 12, a coagulation tank 13, a storage tank 14, a dehydration tank 15, a treated water tank 16, and the like in order toward the downstream.
First, the water 3 to be treated after the contained estrogen 1 is oxidized, decomposed and mineralized is discharged from the treatment tank 4 to the neutralization tank 12 of the post-treatment tank 11. In the neutralization tank 12, a pH adjuster such as caustic soda is added to the water 3 to be treated, and the pH is adjusted to the optimum value for the inorganic flocculant. When hydrogen peroxide remains even in the treated water 3, a neutralizing agent such as catalase is added in order to avoid water pollution.
Next, in the coagulation tank 13, for example, polyaluminum chloride (PAC, Al ₂ (OH) _n Cl _6-n ) or ferric chloride is used as the inorganic coagulant for the water to be treated 3 flowing from the neutralization layer 12. (FeCl ₃ ) is added and stirred. Accordingly, phosphorus ions (for example, phosphate ions H ₂ PO ₄ ⁻ ) in the water to be treated 3 form a colloidal complex 17 with aluminum ions (Al ³⁺ ) and trivalent iron ions (Fe ³⁺ ), and agglomerate. , Precipitate, deposit, can be separated and removed.
In addition, when there is much residual amount of the trivalent iron ion which generate | occur | produced by the Fenton method in the to-be-processed water 3, since this iron ion functions as an inorganic flocculant, the addition of the said inorganic flocculant is unnecessary. On the other hand, for example, an anion may be added as a polymer flocculant to further agglomerate and flock the complex 17.
Then, the water 3 to be treated is supplied from such a coagulation tank 13 to the dehydration tank 15 via the storage tank 14 in the illustrated example. In the dehydration tank 15, the treated water 3 that has been precipitated and sludged into solid and liquid separated by, for example, an F / P-type dehydrator and floculated and dehydrated cake 17 is separated and stored in the container 18. Removed.
And the to-be-processed water 3 purified in this way is further purified in the treated water tank 16, and after having been adjusted to a pH value suitable for external discharge, it is discharged externally.
The post-treatment tank 11 is as described above.

《Action etc.》
The method for treating estrogen 1-containing water of the present invention is configured as described above. Therefore, it becomes as follows.
(1) The treated water 3 such as waste water containing the estrogen 1 is supplied to the treatment device 2. As estrogen 1, estradiol, estrone, estriol, and others can be considered, and in particular, estradiol having a strong biological activity action is a typical example.
Then, the treatment apparatus 2 is used to purify the treated water 3 by oxidizing and decomposing the mixed estrogen 1 by a treatment method based on the treatment process of the Fenton method.

  (2) The treatment apparatus 2 includes a raw water tank 9, a pH adjustment tank 10, a treatment tank 4, a post-treatment tank 11 and the like of the treated water supply means 5 in order. A pH adjusting means 8 is attached to the pH adjusting tank 10. The treatment tank 4 is provided with hydrogen peroxide adding means 6, iron ion adding means 7, pH adjusting means 8, and the like.

  (3) The treated water 3 is first supplied from the raw water tank 9 of the treated water supply means 5 to the treatment tank 4. In addition, before the water 3 to be treated is supplied to the treatment tank 4, an acid pH adjuster such as sulfuric acid is added from the pH adjustment unit 8 in the pH adjustment tank 10, so that the acidity of pH 3 to pH 5 such as about pH 4 is weakly acidic. It is said.

  (4) First, an aqueous solution of hydrogen peroxide is added from the hydrogen peroxide addition means 6 to the water to be treated 3 supplied to the treatment tank 4. The total amount of hydrogen peroxide is added at the beginning of the reaction.

(5) In this treatment tank 4, after the hydrogen peroxide is added in this way, a divalent iron ion solution is added from the iron ion addition means 7 to the water to be treated 3. This addition is performed by repeating a plurality of cycles intermittently divided into a plurality of times by divided addition during the reaction after the addition of hydrogen peroxide.
Moreover, for every divided addition of iron ions, an alkaline pH adjuster such as caustic soda is added from the pH adjusting means 8, so that the water 3 to be treated always maintains a weak acidity of about pH 4, for example. That is, the water to be treated 3 is adjusted to an optimum pH for generating OH radicals.

(6) Now, in the treatment tank 4, OH radicals are generated based on the following first, second, third and fourth reactions.
First, the total amount of hydrogen peroxide added as described above is reduced by divalent iron ions added in portions as a catalyst, and OH radicals are generated each time the addition is performed. That is, by the Fenton main reaction in the reaction formula of Chemical Formula 3 (Chemical Formula 1, Chemical Formula 2), the divalent iron ion donated an electron to hydrogen peroxide to become a trivalent iron ion, and the electron was donated. Hydrogen peroxide generates OH radicals.
The generation of OH radicals is carried out efficiently without waste, since there is no risk of wasteful reaction of OH radicals and divalent iron ions because divalent iron ions are added in portions. Is done. In addition to this, the generation of OH radicals is more efficiently and reliably performed by being maintained in a weakly acidic atmosphere having a pH of about 4. That is, under the weak acid atmosphere, first, electron donation of divalent iron ions is promoted, and further, hydrogen peroxide is decomposed into water and oxygen by the reaction formula (4) and is wasted. Suppressed and avoided, generating full-capacity OH radicals.

(7) Second, OH radicals are hydroxylated by a reduction reaction of hydrogen peroxide with trivalent iron ions generated by an oxidation reaction of divalent iron ions in the treatment tank 4. Ions can also be generated by oxidation.
That is, OH radicals can be generated by the reaction formulas of Chemical Formula 5 and Chemical Formula 6 based on the trivalent iron ions and hydroxide ions generated by the reaction formula of Chemical Formula 3 (Chemical Formula 1, Chemical Formula 2). Also from this aspect, OH radicals are efficiently generated. The OH radicals are also generated in a chain every time iron ions are dividedly added.

(8) In addition to the first and second described above, OH radicals are also generated by the following third and fourth. That is, other than the Fenton main reaction of (6) above, it continues to be efficiently generated by incidental, secondary, and chain reactions.
Thirdly, OH radicals generated by the reaction formula of the chemical formula 3 react with water such as the water to be treated 3 by the reaction formulas of the chemical formulas 7 and 8 to form new OH radicals in a chain. Generated repeatedly.
Fourthly, the trivalent iron ion generated by the reaction formula of Chemical Formula 3 (Chemical Formula 1) and hydrogen peroxide react by the reaction formula of Chemical Formula 11 (Chemical Formula 9 and Chemical Formula 10). New OH radicals are repeatedly generated in a chain.
Note that the generation of the first, second, third, and fourth OH radicals ends when the hydrogen peroxide of the Fenton reagent is exhausted in the processing tank 4.

(9) Now, the OH radicals produced in large quantities in this way have an extremely strong oxidizing power. Therefore, in the treatment tank 4, the estrogen 1 such as estradiol contained in the water to be treated 3 is oxidized and decomposed by the OH radicals, and thus becomes mineralized into a low molecular compound.
Although estrogen 1 is a hard-to-separate organic compound, it has a high treatment rate, decomposition rate, and removal to low molecular weight compounds such as water, oxygen, and carbon dioxide by the chain addition and oxidation reaction of a large amount of OH radicals. It is certainly mineralized at a certain rate.

(10) The estrogen 1 contained in the water 3 to be treated is thus mineralized into water, oxygen, carbon dioxide and the like, and is discharged from the treatment tank 4 to the post-treatment tank 11. The illustrated post-treatment tank 11 includes a neutralization tank 12, a sedimentation tank 13, a coagulation sedimentation tank 14, a filtration tank 15, a pH adjustment tank 16, a treated water tank 17, and the like.
Since hydrogen peroxide is effectively used without waste for the generation of OH radicals as described above, the remaining amount after the treatment is small, and the use of the neutralizing agent in the neutralization tank 12 is negligible or absent. . And the to-be-processed water 3 is adjusted to the state which can be drained by passing through the post-treatment tank 11, and is drained outside.

(11) In this treatment method, as described above, the estrogen 1 contained in the water to be treated 3 is mineralized based on the treatment process of the Fenton method and the like, but this is easily realized.
That is, the amount of chemicals added such as hydrogen peroxide, divalent iron ions, and Fenton's reagent such as a pH adjuster is easily calculated from the theoretical reaction value, and is the same as or larger than the theoretical reaction value. Several times as much as the actual required amount is added, and thus the addition amount is optimized.
The treatment apparatus 2 is provided with a raw water tank 9 and a post-treatment tank 11 with a treatment tank 4 as the center, and a hydrogen peroxide addition means 6, an iron ion addition means 7, a pH adjustment means 8 and the like. It consists of the structure which was made. That is, in this processing method, the processing device 2 having a relatively simple configuration is used, and stable processing is possible.
The operation of the present invention is as described above.

Next, Example 1 of the present invention will be described.
In this Example 1, the reaction process of oxidation and decomposition will be described with respect to the method for treating estrogen 1-containing water of the present invention.
That is, regarding the place described above as the reaction (oxidation and decomposition of estrogen 1) in the treatment tank 4, one example of the oxidation and decomposition reaction process is theoretically verified for estradiol which is a typical example of estrogen 1.
The estradiol contained in the water to be treated 3 includes the chain structure (1) to (1) of the reaction formula shown in the following chemical formulas 13 to 20 including the organic structure of the intermediate of the oxidation and decomposition processes. By following 11), OH radicals (.OH) are sequentially involved and oxidized or added, and low molecular compounds such as water are derived, generated and liberated. It is decomposed and mineralized by low molecular weight compounds such as water (H ₂ O), carbon dioxide (CO ₂ ), and oxygen (O ₂ ).
In addition, in each reaction formula described in Chemical Formula 13 to Chemical Formula 20, in principle, the chemical formula is described in the upper stage, and the structural formula is described in the lower stage.
Incidentally, the structural formula (schematic formula) of a typical example of estrogen 1 is shown in the following chemical formula 12. In Formula 12, (1) is estrone (E1) (C ₁₈ H ₂₂ O ₂ ), (2) is estradiol (E2) (C ₁₈ H ₂₄ O ₂ ) described below, and (3) is Each of estriol (E3) (C ₁₈ H ₂₄ O ₃ ) is shown.

The initial stages of the oxidation and decomposition process are as follows. First, estradiol, which is a starting material to be processed, sequentially undergoes oxidation processes and addition reactions by OH radicals by following the chain processes (1) to (4) of the reaction formulas shown in the following chemical formulas 13 to 16. In the process (4), carbon dioxide, oxygen, etc. are sequentially derived, generated and liberated.
That is, the OH radical oxidizes by taking away the hydrogen atom (H) of the hydroxyl group (—OH) of the decomposition target such as estradiol and the organic structure of the intermediate of the decomposition process, and returns itself to water. An oxygen atom (O) is double-bonded (= O).
Also, the OH radicals deprive the hydrogen atoms (H) of the hydrocarbons to be decomposed and oxidize, and return themselves to water, and the OH radicals following the unpaired electrons of the carbon atoms (C-) are compatible. Thus, the hydroxyl group is regenerated and the above-described reaction is repeated.

Now, after such an initial stage, the process proceeds to the next stage. That is, after the chain processes (1) to (4) of the reaction formulas of the chemical formulas 13 to 16, the chain processes (5) to (11) of the chemical formulas of the following chemical formulas 17 to 20 are followed.
First, in the process (5) -1 of the following chemical formula 17, OH radicals oxidize by depriving hydrogen atoms (H) from water molecules (H ₂ O), and return to water and oxygen molecules (O _2). ) To generate hydrogen radicals (H ⁺ + e ⁻ ).
Therefore, in the process (4) of the chemical formula 16, O = C = C = O cleaved and generated from the residue main body is the hydrogen generated as described above in the process (5) -2 of the chemical formula 17 below. Reduced by radicals to formaldehyde (HCHO). In the process (5) -3 of the chemical formula 17 below, this formaldehyde is oxidized and decomposed into carbon dioxide and water by OH radicals.
On the other hand, the residue body of the process (4) of the chemical formula 16 first passes through the process (6) of the chemical formula 17 and then follows the processes (7) to (10) of the chemical formula 18 to the chemical formula 20 below. Oxidation reaction and addition reaction with OH radicals proceed sequentially for the group. Along with this, water and carbon dioxide are derived, generated and liberated.
Then, the following chemical process 20 (11) is reached, and oxalic acid (C ₂ H ₂ O ₄ ) produced as a final residue is also oxidized by OH radicals, and all of which is attributed to water and carbon dioxide. .

The chemical formula 21 is a general reaction formula of the chain processes (1) to (11) of the chemical formulas 13 to 20. In the general reaction formula of this chemical formula 21, 1 mol of estradiol is theoretically mineralized by 110 mol of OH radical into 18 mol of carbon dioxide, 4.5 mol of oxygen, and 67 mol of water. The
As for the OH radical, the theoretical reaction value may be 110 mol as described above, but the actual required amount is prepared several times as much. The same applies to hydrogen peroxide, divalent iron ions, and the like, which are OH radical products.
About Example 1, it is as above.

Next, a second embodiment of the present invention will be described.
In Example 2, the experimental results of the method for treating water containing estrogen 1 according to the present invention will be described.
That is, in this experiment, estradiol (C ₁₈ H ₂₄ O ₂ ), which is a typical example of estrogen 1, specifically, water to be treated 3 containing its active isomer, 17β-estradiol, was first sample 1 (raw water). As mentioned above, it supplied to the processing tank 4 under normal temperature. And each chemical | medical agent was added in predetermined order, changing the addition amount suitably for every sample 2-1, 2-2, 2-3, 2-4, 2-5.
First, the procedure of this experiment is as follows. That is, first, the water to be treated 3 is treated by the Fenton method of the present invention, and then the complex 17 is aggregated, precipitated and removed by adding PAC, and solid-liquid separation is performed (see the above-mentioned place regarding the post-treatment tank 11). Thus, the filtrated water to be treated 3 was used as an analysis object and an evaluation object in the experiment.
Next, the test conditions for this experiment are as follows. That is, the amount of each chemical added, such as hydrogen peroxide as a source of generation of OH radicals in the Fenton method, ferrous sulfate as a catalyst, sulfuric acid or caustic soda for pH adjustment, PAC for aggregation, etc. is shown in Table 1 below. , As shown in Table 2.

When the experiment was conducted under the test conditions shown in Tables 1 and 2, the test results shown in Tables 3 and 4 below were obtained.
That is, the content of 17β-estradiol contained in the water to be treated 3 to be analyzed and other analysis items are as follows: Sample 1 (raw water) before Fenton treatment, Sample 2-1 after Fenton treatment according to the present invention As a result of measuring each of 2-2, 2-3, 2-4, and 2-5, the test results shown in Tables 3 and 4 were obtained.
The measurement and analysis methods for each analysis item are as follows.
・ Water temperature: JIS K0102 12 (glass rod thermometer)
-PH: JIS K0102 12.1 (glass electrode method)
・ COD-Cr (Oxygen consumption by potassium dichromate)
: JIS K0102 20 (potassium dichromate oxidation method)
(Oxygen conversion)
COD-Mn (oxygen consumption by potassium permanganate at 100 ° C)
: JIS K0102 17 (potassium permanganate titration method at 100 ° C.)
(Oxygen conversion)
・ TOC (total organic carbon)
: JIS K0102 22.1 (combustion oxidation-infrared TOC analysis method)
(C conversion)
-Electrical conductivity: JIS K0102 13.1 (electrode method)
17β-estradiol: solid phase extraction high performance liquid chromatograph mass spectrometry method formic acid: ion chromatograph method acetic acid: gas chromatograph (FID) method oxalic acid: ion chromatograph method

In this experiment, the following points were confirmed by data from the test results shown in Tables 3 and 4.
That is, according to Samples 2-1, 2-2, 2-3, 2-4, and 2-5 treated by the Fenton method of the present invention, 17β-estradiol, which is a typical example of estrogen 1, is oxidized by OH radicals. It was confirmed and evaluated in terms of data that it was oxidized, decomposed and mineralized into carbon, oxygen and water and almost no longer existed in the water 3 to be treated.
This was supported by a decrease in data values of COD-Cr, COD-Mn, TOC, etc., an increase in the electrical conductivity data value, and the like.
It should be noted that lower fatty acids such as formic acid (HCOOH), acetic acid (CH ₃ COOH), and oxalic acid (C ₂ H ₂ O ₄ ) were considered as analysis items because they could be generated in the reaction process. As a result, data values were not detected except in the detection examples of oxalic acid in Samples 2-4 and 2-5. From this aspect, the oxidation, decomposition, and mineralization of water by the OH radical described above were performed. It was supported.
About Example 2, it is as above.

The processing method for estrogen-containing water according to the present invention is provided for explanation of the best mode for carrying out the invention, and is a configuration flow diagram thereof.

DESCRIPTION OF SYMBOLS 1 Estrogen 2 Treatment apparatus 3 Treated water 4 Treatment tank 5 Treated water supply means 6 Hydrogen peroxide addition means 7 Iron ion addition means 8 pH adjustment means 9 Raw water tank 10 pH adjustment tank 11 Post-treatment tank 12 Neutralization tank 13 Aggregation Tank 14 Storage tank 15 Dehydration tank 16 Treated water tank 17 Complex 18 Container

Claims (1)

A treatment method that oxidizes and decomposes estrogen contained in water to be treated based on the Fenton process.
The estrogen is composed of an organic compound having a steroid skeleton having a hormonal action, and hydrogen peroxide, a divalent iron ion solution, and a pH adjuster are added to the water to be treated containing the estrogen,
Hydrogen peroxide is added in the treatment tank at the beginning of the reaction,
In the treatment tank, divalent iron ions are intermittently added repeatedly in a plurality of cycles after the addition of hydrogen peroxide, so that the OH radicals generated below return to water and are wasted. Function to avoid
As for the pH adjuster, an acid pH adjuster is first added to the water to be treated supplied to the treatment tank in the pH adjustment tank, and divalent iron is added in the treatment tank after the addition of hydrogen peroxide. Since pH decreases and acidity increases excessively for each divided addition of ions, an alkaline pH adjuster is added each time,
Therefore, the pH adjuster constantly maintains the water to be treated at a weak acidity of pH 3 to pH 5 to promote the electron donating function of divalent iron ions to hydrogen peroxide, and hydrogen peroxide is decomposed into water and oxygen. , Function to suppress wasted reactions,
The amount of hydrogen peroxide and divalent iron ions added is calculated based on the theoretical reaction value based on the reaction formula, and the required number of moles actually prepared is more calculated.
First, from the specific content of estrogen contained in the water to be treated, the number of moles of the theoretical reaction value of OH radical is obtained as a standard, and then the actual required number of moles of OH radical is larger than this standard. Further calculated from the required number of moles of OH radicals, the theoretical number of moles of reaction of hydrogen peroxide and divalent iron ions, which are OH radical products, is obtained as a reference, and peroxidation The actual required number of moles of hydrogen and divalent iron ions to be prepared is calculated more than this standard,
The addition timing of hydrogen peroxide and divalent iron ions is when hydrogen peroxide is used up and hydrogen peroxide is exhausted from the water to be treated in the treatment tank. When the previously added portion is used up, the divalent iron ions disappear from the water to be treated in the treatment tank.
As for the OH radical production reaction, hydrogen peroxide is reduced with divalent iron ions each time it is added in a divided manner, and in addition to the Fenton main reaction, in which OH radicals are produced, the hydrogen peroxide is further reduced. The generated hydroxide ions are oxidized by trivalent iron ions generated by the oxidation reaction of divalent iron ions to generate OH radicals, and the generated OH radicals are further covered. The reaction of reacting with the water of the treated water to generate new OH radicals and water is repeated in a chain, and the trivalent iron ions and peroxidation produced by the oxidation reaction of the divalent iron ions. The reaction with hydrogen to generate at least new OH radicals is repeated in a chain,
In addition, both the main reaction and the incidental, secondary, and chain reactions are required to maintain the water to be treated in the weakly acidic atmosphere, and hydrogen peroxide is contained in the treatment tank. When used up, the generation of OH radicals ends,
Thus, the estrogen contained in the water to be treated is oxidized and decomposed by the OH radicals thus generated, and mineralized into a low molecular weight compound of water, oxygen, and carbon dioxide. Treatment method of contained water.

Images