JP2013107943A - Decomposing agent and cleaning method of organochlorine-based agricultural chemical - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decomposing agent and cleaning method of organochlorine-based agricultural chemicals, which can clean the organochlorine-based agricultural chemicals simply and in a short period, and does not leave hazardous and hardly treatable by-products remaining by changing chlordanes as the organochlorine-based agricultural chemicals to a state of being decomposable by microbes.SOLUTION: Organochlorine-based agricultural chemicals in contaminated soils and contaminated water are decomposed by imparting the organochlorine-based agricultural chemicals containing a porous copper-containing iron power prepared by mechanically mixing a porous iron powder and a copper resource to soils contaminated with organochlorine-based agricultural chemicals including chlordanes and water contaminated with organochlorine-based agricultural chemicals.

Description

  The present invention relates to an organochlorine pesticide degrading agent and a purification method used for degrading chlordane, which is an organochlorine pesticide contained in water such as soil and groundwater.

  Currently, research and development on a purification technology for chemical substances called persistent organic pollutants (POPs) is progressing. These POPs are not easily decomposed in the natural environment, and are easy to accumulate in living organisms. Furthermore, POPs may travel a long distance on the earth and affect the environment in countries other than the country that emitted POPs. For this reason, POPs are known as chemical substances that can adversely affect our bodies once they are released into the environment. Examples of POPs include chemical substances such as dioxins, PCB (polychlorinated biphenyl), DDT, chlordens, and hexachlorocyclohexane (BHC; 1,2,3,4,5,6-hexachlorocyclohexane).

  In Japan, the manufacture and use of POPs is already prohibited by law. However, there are countries that still use POPs overseas. Further, as described above, even in a country or region that does not use POPs, there is a possibility that environmental pollution due to POPs may progress due to the POPs moving over a long distance on the earth. Therefore, the demand for purification technology for POPs is increasing day by day.

  In this situation, the present applicant is researching and developing POPs purification technology. As a result of the research and development, a technique for decomposing BHC, which is one of POPs, was developed, and the contents thereof are disclosed in Patent Document 1.

JP 2010-17219 A

  Thanks to the technology of Patent Document 1, it has become possible to provide a sufficient purification action for BHC in a simple and short-term manner. On the other hand, there is an increasing demand for purification of POPs other than BHC. In particular, there is a strong demand for purification of chlordane as an organochlorine pesticide among POPs.

  Unlike general organochlorine compounds such as trichlorethylene, these chlordens are not decomposed by microorganisms even when left in nature, and once groundwater and soil are contaminated by chlordens, they are contaminated as they are. Will remain. On the contrary, when soil is contaminated, rainwater and groundwater passing through the contaminated area may be contaminated by chlordane, and the contaminated area may be expanded. Indeed, it has been found that the technique of Patent Document 1 provides a very effective purification action for BHC. On the other hand, the above chlordens may not be currently used in Japan, and there is an unconfirmed part whether the above chlordens can be purified even using the technique of Patent Document 1. Therefore, the current situation is that the technology for purifying chlordane has not been established yet.

  The present invention makes it possible to purify organochlorine pesticides easily and in a short period of time by changing chlordane as an organochlorine pesticide to a state in which microorganisms can be decomposed. It is an object of the present invention to provide an organochlorine pesticide decomposing agent and a purification method for preventing the residue from remaining.

  The present inventors have conducted intensive research to establish a technique for purifying chlordane. On the other hand, the present inventors thought that chlordane is POPs, and it is a difficult task to decompose to a harmless compound. Therefore, in the above-mentioned diligent research, the present inventors changed the chlordane to a level that can be purified by microorganisms (dechlorination), even if it does not lead to decomposition of the chlordane to a harmless compound. ) I examined whether it was possible. As a result, as shown in the embodiments and examples described later, the present inventor has obtained the knowledge that chlordane can be dechlorinated with porous copper-containing iron powder. The present inventor has conceived a method capable of decomposing the dechlorinated compound by microorganisms and finally purifying chlordane.

  Hereinafter, in this specification, “decomposition” mainly refers to changing the carbon skeleton structure of chlordane itself (for example, changing a multi-membered ring structure to a one-membered ring structure). On the other hand, “degradation of pesticides” includes dechlorination (epoxy structure changes due to deoxygenation in some cases) even if the carbon skeleton structure of chlordane itself does not change. It is mainly meant to decompose to the extent that microorganisms can be decomposed to a level that can be decomposed.

The embodiments of the present invention made based on the above findings are as follows.
The first aspect of the present invention is:
An organochlorine pesticide degrading agent comprising a porous copper-containing iron powder obtained by mechanically mixing a porous iron powder and a copper source, and decomposing an organochlorine pesticide containing chlordane.
The second aspect of the present invention is:
Soil contaminated with organochlorine pesticides containing chlordane, organochlorine pesticide decomposer containing porous copper-containing iron powder mechanically mixed with porous iron powder and copper source, and organochlorine A purification method characterized by decomposing organochlorine pesticides in contaminated soil and contaminated water by applying to at least one of water contaminated with pesticides.

  According to the present invention, by changing chlordane as an organochlorine pesticide to a state in which microorganisms can be decomposed, it is possible to purify the organochlorine pesticide easily and in a short period of time, which is harmful and difficult to treat. It is possible to provide an organochlorine pesticide degrading agent and a purification method that prevent by-products from remaining.

It is a graph which shows the result of the agricultural chemical decomposition | disassembly of the parent substance in Example 1A (Chlordenes: Heptachlor epoxide, reaction temperature: 70 degreeC). It is a graph which shows the result of the agrochemical decomposition | disassembly of the parent substance in Example 1B (Chlordenes: Heptachlor epoxide, Reaction temperature: Room temperature). It is a graph which shows the relationship between reaction time, deCl concentration, and peak area ratio in Reference Example 1A (chlordane: heptachlor epoxide, reaction temperature: 70 ° C.). (A) is a graph when the reaction time is 0 to 30 hours, and (b) is a graph when the reaction time is 0 to 120 days. The peak area ratio is a peak area ratio for each intermediate calculated from a peak area value corresponding to each intermediate in gas chromatography, assuming 1 ppm as the parent substance. Hereinafter, the description of the “peak area ratio” is the same. It is a graph which shows the relationship between reaction time, deCl concentration, and peak area ratio in Reference Example 1B (chlordane: heptachlor epoxide, reaction temperature: room temperature). It is a graph which shows the result of the mass spectrum of the parent substance itself in Reference Example 1A. It is a graph which shows the result of the mass spectrum of the intermediates 1-4 in the reference example 1A, (a)-(d) respond | corresponds to the intermediates 1-4. It is a graph which shows the result of the mass spectrum of the intermediates 5-8 in the reference example 1A, (a)-(d) respond | corresponds to the intermediates 5-8. It is a graph which shows the result of the agrochemical decomposition | disassembly of the parent substance in Example 2A (Chlordenes: Heptachlor, Reaction temperature: 70 degreeC). It is a graph which shows the relationship between reaction time, deCl concentration, and peak area ratio in Reference Example 2A (chlordane: heptachlor, reaction temperature: 70 ° C). (A) is a graph when the reaction time is 0 to 30 hours, and (b) is a graph when the reaction time is 0 to 120 days. It is a graph which shows the relationship between the reaction time in Reference Example 2B (chlordane: heptachlor epoxide, reaction temperature: room temperature), deCl concentration, and peak area ratio. It is a graph which shows the result of the mass spectrum of the parent substance itself in Reference Example 2A. It is a graph which shows the result of the mass spectrum of the intermediates 1-3 in the reference example 2A, (a)-(c) respond | corresponds to the intermediates 1-3. It is a graph which shows the result of the mass spectrum of the intermediates 4-6 in the reference example 2A, (a)-(c) respond | corresponds to the intermediates 4-6. It is a graph which shows the result of the mass spectrum of the intermediates 7-9 in the reference example 2A, (a)-(c) respond | corresponds to the intermediates 7-9. It is a graph which shows the result of the mass spectrum of intermediates 10-12 in Reference Example 2A, and (a) to (c) correspond to intermediates 10-12. It is a graph which shows the relationship between the reaction time, deCl concentration, and peak area ratio in Reference Example 3A (chlordane: g-chlordane, reaction temperature: 70 ° C.). It is a graph which shows the relationship between reaction time, deCl concentration, and peak area ratio in Reference Example 3B (chlordane: g-chlordane, reaction temperature: room temperature). It is a graph which shows the result of the mass spectrum of the parent substance itself in Reference Example 3A. It is a graph which shows the result of the mass spectrum of the intermediates 1-4 in the reference example 3A, (a)-(d) respond | corresponds to the intermediates 1-4. It is a graph which shows the result of the mass spectrum of the intermediates 5-8 in the reference example 3A, (a)-(d) respond | corresponds to the intermediates 5-8.

This embodiment will be described in the following procedure.
<1. Organochlorine pesticide decomposer>
a) Porous iron powder b) Copper source <2. Purification method>
<3. Advantages of the embodiment>

<1. Organochlorine pesticide decomposer>
The organochlorine pesticide decomposing agent of this embodiment includes porous copper-containing iron powder obtained by mechanically mixing porous iron powder and a copper source, and further contains other components as necessary. .

a) Porous iron powder The above-mentioned porous iron powder means that the particle group constituting the iron powder has pores of various sizes inside and outside. The pores may be in contact with the outside of the particles or may be independent.
The porous iron powder preferably contains reduced iron powder. The reduced iron powder is preferably produced by reduction of iron ore, and the particle size of the reduced iron powder is not particularly limited and can be appropriately selected according to the purpose.
As said raw material iron powder, what is necessary is just to have iron as a main component, and what does not contain components, such as chromium and lead used as a secondary pollution source, is preferable. There is no restriction | limiting in particular about the composition of the said raw material iron powder, According to the objective, it can select suitably, It is preferable that total iron is 80% or more and metallic iron is 75% or more.
There is no restriction | limiting in particular as said reduced iron powder, A commercial item can be used, For example, the reduced iron powder (rotary kiln powder) by DOWA IP creation company etc. are used suitably as this commercial item.

b) Copper source There is no restriction | limiting in particular as said copper source, According to the objective, it can select suitably, For example, copper salt, metallic copper, or a copper solution etc. are mentioned.
The copper salt is not particularly limited as long as it becomes a copper source, can be further contacted and scattered on the surface of the iron powder, and various copper salts can be used, but copper sulfate is particularly preferable.
The copper sulfate can be usually obtained in the form of CuSO ₄ .5H ₂ O having crystal water, but in this embodiment, it is preferable to remove crystal water as much as possible. Moisture from crystal water, moisture adhering to the mill surface, moisture in the atmosphere, etc., are produced by the copper sulfate aqueous solution during mixing of the reduced iron powder and copper sulfate powder, and the Cu ions in the aqueous solution are the surface of the iron particles. In some cases, the iron particles are precipitated and deposited as metallic copper, and the surface of the iron particles may be coated with the deposited metallic copper film. If the surface of the iron powder particles is completely covered with metallic copper, the function as an organochlorine pesticide decomposer may be reduced. Therefore, it is preferable to remove the copper sulfate crystal water as much as possible, and it is better to mix with iron powder in a dry manner so that moisture does not mix as much as possible, and to mix in an inert gas atmosphere. . CuSO ₄ .5H ₂ O can remove crystal water by heating. For example, 2 molecules can be removed by heating at 45 ° C., 4 molecules can be removed by heating at 110 ° C., and all molecules can be removed by heating at 250 ° C.
In addition to the use of metallic copper powder as the copper source, a solution in which a copper salt is dissolved in a solution, for example, a copper sulfate solution in which copper sulfate is dissolved, is brought into contact with the porous iron powder described above to form a metal on the iron particle surface. There is a method of depositing copper or a copper salt.

  The copper content in the porous copper-containing iron powder is preferably 0.1% by mass to 10% by mass in terms of mass% of the ratio of copper to iron (Cu / Fe), and 0.1% by mass. % To 1% by mass is more preferable. If the content is 0.1% by mass or more, it becomes possible to sufficiently satisfy the pesticide decomposing ability of the required organochlorine pesticide, and uneven distribution of the performance does not occur in the iron powder. Moreover, if it is 10 mass% or less, it becomes possible to obtain the performance commensurate with the amount of added copper from the Fe / Cu balance on the surface of the iron particles, and excess copper diffuses and flows out into the ground water as copper ions. The fear can also be suppressed.

The manufacturing method of the organochlorine pesticide decomposing agent described above adds copper sulfate (powder) to the raw iron powder while applying shearing force and pressure to the raw iron powder particles and crushing the raw iron powder to the extent that it can be crushed. . At the time of pulverization, the pulverization strength is such that the porous state (irregularities and voids) on the surface of the iron powder is not crushed and smooth. If the strength is enough to pulverize the raw iron powder, the copper sulfate adheres to the raw iron powder and is strong enough to adhere.
The mechanical mixing of the porous iron powder and the copper source is preferably performed using a pulverizing / mixing device of a type that drives a pulverizing medium in a container such as a vibrating ball mill or a rotating ball mill. In this embodiment, it is preferable not to use a dispersant, a lubricant, or the like that is used in order to facilitate mixing and pulverization in the present embodiment.
Even if the copper source is a copper solution, the processing operation is the same as in the case of a copper salt or copper powder. What is necessary is just to set mixing intensity, time, and compounding quantity ratio suitably. This is because copper precipitates on the surface of the iron powder from the ionization tendency even if it is in contact with the iron powder if it is a copper solution.

  The average diameter of the porous copper-containing iron powder is preferably 1 μm to 500 μm, more preferably 25 μm to 250 μm, typically the average plane diameter is in the range of 50 μm to 500 μm, and the average thickness is in the range of 1 μm to 50 μm. Is preferred.

  The organochlorine pesticide degrading agent of this embodiment decomposes the organochlorine pesticide into water, soil, inorganic substances, organic substances, or a mixture thereof contaminated with chlordane, which is an organochlorine pesticide (final decomposition). In particular, in the environmental field, it can be used to purify wastewater, groundwater, soil, exhaust gas, etc. contaminated with organochlorine pesticides.

また、オキシクロルデンについては以下の通りである。

また、ノナクロル（ｔｒａｎｓ型）については以下の通りである。

（以上、出展：環境省編「農薬等の環境残留実態調査分析法」） In the present specification, “chlordens” are those in which at least a part of polycyclic aromatic hydrocarbons is chlorinated (for example, those in which five-membered hydrocarbons are bonded and at least part of them are chlorinated). is there. When specific examples are listed, heptachlor, heptachlor epoxide (Isomer A) and the like may be mentioned in addition to γ-chlorodene, g-chlordane, oxychlordene and nonachlor.
Among these, the physical properties and outline of chlordane are as follows.

The oxychlordene is as follows.

Nonachlor (trans type) is as follows.

(Exhibited above: Ministry of the Environment, “Environmental residue survey and analysis method for agricultural chemicals”)

In addition, a list of structural formulas of chlordane including the above compounds is described in the following [Chemical Formula 4]. (A) is γ-chlordane, (b) is heptachlor, (c) is g-chlordane, (d) is nonachlor, den, (e) is heptachlor epoxide (Isomer A), (f) is Oxychlordane.

<2. Purification method>
In the purification method of the present embodiment, the organochlorine pesticide degrading agent of the present embodiment is applied to at least one of soil contaminated with the organic chlorine-based pesticide and water contaminated with the organochlorine-based pesticide, Organochlorine pesticides (agrochemicals containing chlordane) in contaminated soil and contaminated water are dechlorinated and finally decomposed.

Although it is an example as a purification method of this embodiment, performing as follows is mentioned.
First, since chlordane has very low solubility in water, mass transfer in soil is small. For this reason, in order to increase a contact opportunity with an organochlorine pesticide decomposing agent, it is preferable to perform kneading | mixing suitably.

  The purification method of the present embodiment can be executed by a simple technique of mixing with contaminated water or spraying or mixing with contaminated soil. In addition, since the dechlorination rate is high in the purification method of the present embodiment, short-term purification is possible. Moreover, you may use the method of adding or cultivating the microorganisms which decompose | degrade a by-product (dechlorination product) in process object soil. The above-described microbial treatment has a significant point in that the purification period is relatively long, but the treatment cost is low. Since microorganisms exist in the mainland and water, it is efficient to culture and use microorganisms that degrade replicating organisms. External effective microorganisms may be used.

There is no restriction | limiting in particular as the provision method to the contaminated soil and contaminated water of the said organochlorine pesticide decomposing agent of this embodiment, According to the objective, it can select suitably, For example, disperse | distribute the said decomposing agent to water. It can be used by spraying on contaminated soil in the wet state, sprinkling water on contaminated soil, or mixing with contaminated water.
Moreover, as a purification method of contaminated soil, for example, a heavy machine such as an earth auger used in a conventional construction method can be used as it is. In addition, a commercially available packaging container such as a flexible container or a paper bag is sufficient for storing the organochlorine pesticide degrading agent, and is excellent in both handling and storage.

<3. Advantages of the embodiment>
According to this embodiment, even if chlordane is not decomposed to a harmless compound, chlordane can be changed (dechlorinated) to a level that can be purified by the hands of microorganisms. This dechlorinated compound can be decomposed by microorganisms, and finally chlordane can be purified. As a result, it is possible to purify organochlorine pesticides easily and in a short period of time, and to prevent harmful and difficult-to-treat by-products from remaining.

Examples of the present invention will be described below, but the present invention is not limited to these examples. In addition, as an outline | summary of an Example, in [Examples 1-3], the result of the agrochemical decomposition | disassembly by the organochlorine pesticide decomposing agent of an Example with respect to each compound in chlordane is shown. In [Example 1], the reaction temperature between the chlordane aqueous solution and the copper-containing iron powder was set to 70 ° C. <Example 1A>, and the reaction temperature at room temperature was set to <Example 1B>. The same applies to [Example 2] and [Example 3].
Then, the result of investigating the mechanism (dechlorination route) that caused the agricultural chemical decomposition in [Examples 1 to 3] is shown as [Reference Examples 1 to 3].
The above-described first embodiment is expressed for each layer as follows.
[Example 1 (Chlordenes: heptachlor epoxide)] (Results)
<Example 1A (reaction temperature: 70 ° C.)>
<Example 1B (reaction temperature: room temperature)>
[Reference Example 1 (Chlordenes: Heptachlor Epoxide)] (Mechanism)
<Reference Example 1A (reaction temperature: 70 ° C.)>
<Reference Example 1B (reaction temperature: room temperature)>
<Identification of Intermediate in Reference Example 1>
In [Example 2], the case where chlordane is heptachlor will be described in the same manner as [Example 1] above.
In [Example 3], the case where chlordane is g-chlordene will be described in the same manner as [Example 1] above.

Example 1 (Chlordenes: Heptachlor Epoxide)
<Example 1A (reaction temperature: 70 ° C.)>
In this example, a test was conducted to confirm the effect of treating chlordane with an organochlorine pesticide decomposer. In this example, the test was conducted in a simple system consisting only of a chlordane aqueous solution and copper-containing iron powder as pseudo-polluted water.

  As the chlordane aqueous solution, an aqueous solution in which pure water and heptachlor epoxide were mixed with a brown-colored vial was used. The concentration of heptachlor epoxide was 1 ppm. Hereinafter, heptachlor epoxide is also simply referred to as “parent substance”.

As the copper-containing iron powder, “iron powder E401”, which is one brand of iron powder for soil / groundwater purification manufactured by DOWA IP Creation, was used. As an example of the manufacturing method of this iron powder E401, it is as described in Patent Document 1, but the following is a reprint.
Reduced iron powder (DOWA IP Creation Co., Ltd., rotary kiln powder) 500g, and copper sulfate (monohydrate) powder 14.0g which was heat-treated in a 200 ° C air stream for 2 hours in advance and dehydrated crystal water. Were charged into a rotating ball mill and mechanically mixed in a dry manner to obtain iron powder E401, which is a porous copper-containing iron powder in which particles of both powders were joined.

  The above chlordane aqueous solution and copper-containing iron powder were prepared, and both were mixed in the above vial bottle. At that time, the atmosphere in the vial was a nitrogen atmosphere. And after making the inside of a vial bottle into 70 degreeC, the mixed aqueous solution was shaken in the dark place at 215 rpm. The reason why the inside of the vial was set to 70 ° C. is that, in terms of Arrhenius equation, the reaction rate can be improved by 9.3 times compared to room temperature, the reaction time was shortened, and the pesticide degradation effect was relatively high. This is because it can be confirmed early. In addition, this mixed aqueous solution was prepared for every reaction time. Although it mentions later, it is for investigating a time-dependent change about the density | concentration of an agrochemical (heptachlor epoxide).

  The mixed aqueous solution thus obtained was allowed to stand and phase-separated into an oil phase and an aqueous phase. Here, 2 ml of the aqueous phase was sampled, and chloride ions in the aqueous solution were analyzed by ion chromatography. By examining the chloride ions in the aqueous phase, it is possible to grasp how much chlorine is finally desorbed from the parent substance (hereinafter also referred to as “de-Cl concentration”). This result is used in a reference example described later.

  Thereafter, 10 ml of hexane and acetone (hexane: acetone = 1: 1) was added to the mixed aqueous solution, and the mixture was allowed to stand overnight, and the parent substance remaining in the aqueous phase was extracted into the oil phase. Thereafter, the oil phase was analyzed by GC / MS to determine the concentration of the parent substance. After performing this measurement, the oil phase was withdrawn, and 10 ml of hexane and acetone (hexane: acetone = 1: 1) was newly added to the remaining aqueous phase and allowed to stand overnight. The remaining parent material was extracted again into the oil phase. The above extraction was carried out until no parent substance was detected in this way, and the amount (concentration) of the parent substance that would eventually be present in the oil phase without being decomposed (dechlorinated) by the copper-containing iron powder was measured. . By carrying out like this, the agrochemical degradation effect of the copper containing iron powder in a present Example can be confirmed. In this example, the parent substance was not detected by only one extraction.

  In this extraction, not only the parent substance but also each substance that has been dechlorinated (depending on the number of detached chlorines, two chlorines are removed, three chlorines are released, etc.) Will be extracted into the phase. Then, as described in [Reference Example 1] to be described later, this oil phase is analyzed by GC / MS, and concentration changes and structural formulas of these substances (hereinafter, also referred to as “intermediates”) are identified. To investigate the mechanism (dechlorination pathway) that caused pesticide degradation.

The result of the agricultural chemical decomposition | disassembly of the parent substance (heptachlor epoxide) in a present Example is shown in FIG. In FIG. 1, the horizontal axis represents the reaction time, and the vertical axis represents the concentration of the parent substance in the oil phase. From this, it can be seen that most of the parent substance has already been decomposed by agricultural chemicals when the reaction time is 3 hours, dechlorination can be carried out, and it can be decomposed by microorganisms. In FIG. 1, the reaction rate constant was 4.927 h ⁻¹ and the half-life was 0.141 h. This reaction has a reaction rate according to the pseudo first order rate equation, which is presumed to be due to an excess of hydrogen ions. When the reaction time is 1 week, N.I. D. (Not detected).

<Example 1B (reaction temperature: room temperature)>
In this example, the temperature in the vial was room temperature (20 ° C.). Otherwise, it was the same as <Example 1A>. The result is shown in FIG. Looking at Figure 2, even under mild conditions such as room temperature, if it takes 21 days, most of the parent substance, which has been said to be difficult to break down by microorganisms until now, will decompose pesticides. You can see that

[Reference Example 1 (Chlordenes: heptachlor epoxide)]
<Reference Example 1A (reaction temperature: 70 ° C.)>
Hereinafter, the results of “analysis of chloride ions in the aqueous phase by ion chromatography” and “analysis of intermediates finally present in the oil phase” performed in <Example 1A> will be described. 3A and 3B are graphs in which the horizontal axis represents the reaction time and the right vertical axis represents the deCl concentration. The left vertical axis is calculated from the peak area value corresponding to each intermediate (referred to as intermediates 1, 2, 3,...) In gas chromatography, where 1 ppm of the parent substance heptachlor epoxide is 1. It is the peak area ratio for each intermediate 1-8. When the area ratio decreases with time, it is changed to another intermediate by further dechlorination. 3A is a graph when the reaction time is 0 to 30 hours, and FIG. 3B is a graph when the reaction time is 0 to 120 days.

  As shown in FIG. 3 (a), each intermediate is formed immediately after the start of the reaction, and among them, intermediates 1 to 4 are produced in a large amount. It is low. Moreover, when FIG.3 (b) is seen, the density | concentration of the intermediates 1-8 is very low at the time of 7 days. On the other hand, the concentration of intermediates 7 and 8 has increased (ie, intermediates 7 and 8 are formed again) at 49 days. However, the concentration of intermediates 7 and 8 is low again at 98 days. The dechlorination concentration was 35.9% in terms of dechlorination rate at 98 days, indicating that dechlorination was moderate.

<Reference Example 1B (reaction temperature: room temperature)>
Even when the temperature in the vial was set to room temperature (20 ° C.), similarly to FIG. 3, the horizontal axis represents the reaction time, the right vertical axis represents the deCl concentration, and the left vertical axis represents the peak area ratio of each intermediate. Was obtained (FIG. 4). As seen from this, when the reaction time was 21 days, only the intermediate 3 was confirmed, and other substances could not be confirmed.

なお、［化５］の上側の反応式は、ＲＤＡイオンとしてシクロペンタジエン（ｍ／ｚ＝６５．０）やヘキサクロロシクロヘキサジエン（ｍ／ｚ＝２７１．８）のイオンが挙げられる。また、［化５］の下側の反応式は、ＲＤＡイオンとして１，２−エポキシシクロペンタン−３−エン（ｍ／ｚ＝８１．０）やヘキサクロロシクロヘキサジエン（ｍ／ｚ＝２７１．８）のイオンが挙げられる。
これにより、各中間物が有する構造の一部を同定し、最終的に各中間物全体の構造を同定した。 <Identification of Intermediate in Reference Example 1>
Furthermore, mass spectrum analysis was performed in order to identify the structures of the intermediates 1 to 8. In this identification, the retro Diels-Alder reaction (RDA) (Cooper et al., 1979) (the following [Chemical Formula 5]) was used as a reference.

In addition, the reaction formula on the upper side of [Chemical Formula 5] includes ions of cyclopentadiene (m / z = 65.0) and hexachlorocyclohexadiene (m / z = 271.8) as RDA ions. The reaction formula below [Chemical Formula 5] is 1,2-epoxycyclopentane-3-ene (m / z = 81.0) or hexachlorocyclohexadiene (m / z = 271.8) as RDA ions. Ions.
Thereby, a part of the structure of each intermediate was identified, and finally the structure of each intermediate was identified.

  The mass spectrum results of heptachlor epoxide (parent substance) itself and each intermediate in this example (chlordens: heptachlor epoxide) will be described below. FIG. 5 is a graph showing the results of the mass spectrum of the parent substance itself. 6A to 6D are graphs showing the results of mass spectra of intermediates 1 to 4. FIG. 7A to 7D are graphs showing the results of mass spectra of intermediates 5 to 8. FIG.

As described above, in <Reference Example 1A>, a large amount of intermediates 1 to 4 are formed immediately after the start of the reaction. Further, as shown in FIGS. 6A to 6D, an ion of pentachlorocyclopentadiene [C5H1Cl5] ⁺ (one chlorine is eliminated from hexachlorocyclopentadiene, m / z = 237.7) is confirmed. Has been. Further, considering that m / z = 318.8 in [M] ⁺ , it can be seen that two chlorines are detached from the parent substance. In addition to this, as a result of taking into account the difference in the dissociation energy of chlorine for each difference in the position of the bonding carbon in the parent substance, in addition to the part surrounded by the solid line in the following [Chemical 6], “<1 It is considered that any one of “part of>” and “part of <2>” is eliminated.

  Furthermore, the results of the mass spectrum of intermediate 1 (FIG. 6 (a)) and intermediate 3 (FIG. 6 (c)) are almost the same, and the intermediate is present even if the reaction time is 21 days in <Reference Example 1B>. Since the product 3 is produced in a large amount, the intermediate 1 and the intermediate 3 are separated from the portion surrounded by the solid line ○ in [Chemical 6] above, and any chlorine in the portion <1> is eliminated. It is estimated that On the other hand, the results of the mass spectra of the intermediate 2 (FIG. 6 (b)) and the intermediate 4 (FIG. 6 (d)) are almost the same, and both are produced in a small amount compared to the intermediate 3. From this, it is presumed that intermediate 2 and intermediate 4 have any chlorine in the portion <2> desorbed in addition to the portion circled by the solid line in [Chemical Formula 6] above. That is, it is presumed that intermediates 1 to 4 have two chlorines eliminated.

Next, when the intermediate 5 (FIG. 7 (a)) is examined, a peak related to an ion of [C5H1Cl4] ⁺ (two chlorines eliminated from hexachlorocyclopentadiene) appears. Further, in the intermediate 5, it is presumed that dechlorination is proceeding as shown in the following [Chemical 7] from the fact that it is not the same as the spectrum result of other intermediates and the dissociation energy of chlorine. The That is, it is presumed that the portion surrounded by a solid line ○ is dechlorinated, and in the case of the intermediate 5, three chlorines are detached.

なお、中間物７（図７（ｃ））のマススペクトルにおいては、エポキシ部分を含有する１，２−エポキシシクロペンタン−３−エンのピークが出現していることから、中間物６のような構造変化を伴わず、上記［化６］の<２>の部分のいずれかの塩素が脱離していると推測される。結局のところ、中間物６，７は塩素が４個脱離していると推測される。 Next, the intermediate 6 (FIG. 7B) is examined. In the above [Chemical Formula 6], the portion surrounded by a solid circle, the two chlorines in the <1> portion, and the portion in the <2> It is estimated that any chlorine is desorbed. On the other hand, since a peak due to cyclopentadiene (m / z = 65.9) appears, the epoxy moiety in the parent substance changes to a cyclopentadiene structure as shown in [Chemical Formula 8] below. In addition, it is expected that any chlorine in the portion <2> is eliminated.

In addition, in the mass spectrum of the intermediate 7 (FIG. 7C), since a peak of 1,2-epoxycyclopentan-3-ene containing an epoxy moiety appears, It is presumed that any chlorine in the portion <2> in the above [Chemical Formula 6] is eliminated without a structural change. After all, it is speculated that intermediates 6 and 7 are desorbed four chlorines.

Finally, when the intermediate 8 (FIG. 7 (d)) is examined, it is presumed that dechlorination proceeds as shown in the following [Chemical 9] from the result of the spectrum. That is, it is presumed that five chlorines are eliminated from the intermediate 8.

As described above, as a result of identifying the intermediate in [Reference Example 1], it can be presumed that the agrochemical decomposition (dechlorination) pathway in this Example occurs along the pathway [Chem. In addition, the intermediate from which only one chlorine was eliminated could not be confirmed in [Reference Example 1].

[Example 2 (chlordane: heptachlor)]
<Example 2A (reaction temperature: 70 ° C.)>
In this example, heptachlor was used as the chlordane. Other than that, it was the same as [Example 1], and the state of agrochemical decomposition of the parent substance (heptachlor) was examined.

  The result of the agricultural chemical decomposition of the parent substance (heptachlor) in this example is shown in FIG. The horizontal axis in FIG. 8 is the reaction time, and the vertical axis is the concentration of the parent substance in the oil phase. As shown in FIG. 8, when the reaction time is one day, most of the parent substance has already been decomposed by agricultural chemicals, can be dechlorinated, and can be decomposed by microorganisms. Recognize. Even when the reaction time was 30 minutes, most of the parent substance had already been decomposed by agricultural chemicals.

<Example 2B (reaction temperature: room temperature)>
Further, in this example, the state of decomposition of the parent chemical by agrochemical was also examined when the reaction temperature was room temperature. As a result, when the reaction time is 21 days, the parent substance is N.P. D. It was confirmed that most of the parent substance was decomposed by agricultural chemicals.

[Reference Example 2 (Chlordenes: Heptachlor)]
<Reference Example 2A (reaction temperature: 70 ° C.)>
Hereinafter, the results of “analysis of chloride ions in the aqueous phase by ion chromatography” and “analysis of intermediates finally present in the oil phase” performed in <Example 2A> will be described. In addition, about the part which does not mention specially, it is the same as that of [Reference example 1].

  9A and 9B are graphs in which the horizontal axis represents the reaction time and the right vertical axis represents the deCl concentration. The left vertical axis represents the peak for each intermediate 1 to 12, calculated from the peak area value corresponding to each intermediate (intermediate 1 to 12), with 1 ppm heptachlor as the parent substance as 1 in gas chromatography. It is an area ratio. In one intermediate, the smaller this area ratio is, the more dechlorination is performed and the other intermediate is changed. 9A is a graph when the reaction time is 0 to 30 hours, and FIG. 9B is a graph when the reaction time is 0 to 120 days.

As shown in FIG. 9A, when 1 hour has elapsed from the start of the reaction, the intermediates 1 to 3 are N.P. D. Met. In addition, when it was 24 hours from the start of the reaction, the intermediate 7 was N.P. D. Met. Other intermediates were formed immediately after the reaction.
Moreover, when FIG.9 (b) is seen, the density | concentration of the intermediates 6 and 9 is very low at the time of 7 days. Similarly, the concentration of the intermediate 10 is extremely low at 49 days. Furthermore, intermediates 8, 11 and 12 were slightly present while the concentrations of intermediates 4 and 5 were very low at 98 days. The dechlorination concentration was 82.6% in terms of dechlorination rate at 98 days.

<Reference Example 2B (reaction temperature: room temperature)>
Even when the temperature in the vial was set to room temperature (20 ° C.), as in FIG. 9, the horizontal axis represents the reaction time, the right vertical axis represents the deCl concentration, and the left vertical axis represents the peak area ratio of each intermediate. Was obtained (FIG. 10). From this, when the reaction time was 21 days, it was not possible to confirm intermediates 1 to 3, 6, and 7.

<Identification of Intermediate in Reference Example 2>
Furthermore, mass spectrum analysis was performed in order to identify the structures of the above intermediates 1 to 12. In this identification, as in [Reference Example 1], RDA was used as a reference.

  The mass spectrum results of heptachlor (parent substance) itself and each intermediate in this example (chlordane: heptachlor) will be described below. FIG. 11 is a graph showing the result of the mass spectrum of the parent substance itself. 12A to 12C are graphs showing the results of mass spectra of the intermediates 1 to 3. FIG. 13A to 13C are graphs showing the results of mass spectra of the intermediates 4 to 6. FIG. 14A to 14C are graphs showing the results of mass spectra of the intermediates 7 to 9. FIG. FIGS. 15A to 15C are graphs showing the results of mass spectra of the intermediates 10-12.

First, the intermediates 1 to 6 (FIGS. 12A to 12C and FIGS. 13A to 13C) are examined. Ions ([C5H1Cl5] ⁺ and [ C5H1Cl4] ⁺ ) is confirmed. In addition, the presence of 2,3-dihydroxycyclopentadiene ions presumed to be derived from cyclopentadiene, which is an RDA ion, is also confirmed. That is, it can be seen that the intermediates 1 to 6 have a structure in which one chlorine is eliminated from 2,3-dihydroxycyclopentadiene and a hydroxyl group is added.

  On the other hand, when the intermediates 7 to 12 (FIGS. 14 (a) to (c) and FIGS. 15 (a) to 15 (c)) are examined, ions of hexachlorocyclopentadiene from which chlorine is eliminated are present, but the hydroxyl group is not present. Presence of added 2,3-dihydroxycyclopentadiene ion cannot be confirmed. That is, it can be seen that the intermediates 7 to 12 have a structure in which one chlorine is eliminated from 2,3-dihydroxycyclopentadiene but no hydroxyl group is added.

なお、塩素の解離エネルギーについては［化１２］の右下部分に記載しているとおりである。その部分における○で囲んだ数値は、ナンバリングされた各炭素（Ｃ）と結合したＣｌの脱離しやすさの順番を示している。 The dechlorination pathway in which these intermediates 1 to 12 are generated is shown in the following [Chemical Formula 11] and [Chemical Formula 12] below. [Chemical Formula 11] is a dechlorination route for intermediates 1 to 6 to which a hydroxyl group is added. Similarly, [Chemical Formula 12] is a dechlorination route for Intermediates 7 to 12 to which no hydroxyl group has been added. Hereinafter, the dechlorination route of the present embodiment will be described with reference to these.

The dissociation energy of chlorine is as described in the lower right part of [Chemical 12]. A numerical value surrounded by a circle in the portion indicates the order of the detachment of Cl bonded to each numbered carbon (C).

Considering intermediate 1 (FIG. 12 (a)), the presence of ions of 2,3-dihydroxycyclopentadiene, and pentachlorocyclopentadiene [C5H1Cl5] ⁺ (one from which chlorine was eliminated from hexachlorocyclopentadiene, m /Z=237.7), it is estimated that two chlorines are eliminated and two hydroxyl groups are added ((a) of [Chemical Formula 11]).

  When the intermediate 2 (FIG. 12B) and the intermediate 3 (FIG. 12C) are studied, it is estimated that four chlorines are eliminated and one hydroxyl group is added. Taking into account that the peaks of both are similar, it is speculated that Intermediate 2 and Intermediate 3 are a combination of <1> or <2> in (b) of [Chemical Formula 11]. The present inventors are intensively studying.

  When the intermediate 4 (FIG. 13A) and the intermediate 5 (FIG. 13B) are examined, it is estimated that three chlorines are eliminated and one hydroxyl group is added. Taking into consideration that the mass spectra of both are similar, it is presumed that Intermediate 4 and Intermediate 5 are either <1> or <2> in (c) of [Chemical Formula 11].

  When the intermediate 6 (FIG. 13C) is examined, it is estimated that three chlorines are eliminated and two hydroxyl groups are added. From this, it is presumed that the intermediate 6 is (d) of [Chemical Formula 11].

  On the other hand, when the intermediates 7 to 9 (FIGS. 14 (a) to (c)) to which no hydroxyl group is added are examined, four chlorines are eliminated. Further, taking into consideration that these mass spectra are similar to each other, it is presumed that the intermediates 7 to 9 are any one of (a) of [Chemical Formula 12].

  When the intermediate 10 (FIG. 15A) is studied, five pieces of chlorine are eliminated. From this, the intermediate 10 is presumed to be (b) of [Chemical 12].

  When the intermediate 11 (FIG. 15 (b)) and the intermediate 12 (FIG. 15 (c)) are examined, six chlorines are eliminated. Taking into account that the mass spectra of both are similar to each other, it is presumed that the intermediate 11 and the intermediate 12 are any one of (C) of [Chemical 12].

  As described above, as a result of identifying the intermediate in [Reference Example 2], it is speculated that the agrochemical decomposition (dechlorination) pathway in this Example occurs in the pathway such as [Chemical Formula 11] or [Chemical Formula 12]. it can. In addition, the intermediate from which only one chlorine was eliminated or the intermediate from which two hydroxyls were eliminated without hydroxyl group could not be confirmed in [Reference Example 2].

[Example 3 (chlordane: g-chlordane)]
<Example 3A (reaction temperature: 70 ° C.)>
In this example, g-chlordane was used as chlordane. Other than that was carried out similarly to [Example 1], and investigated the state of agrochemical decomposition of the parent substance (g-chlordane). As a result, when the reaction time is 49 days, the parent substance is N.P. D. It was confirmed that most of the parent substance was decomposed by agricultural chemicals.

<Example 3B (reaction temperature: room temperature)>
Further, in this example, the state of decomposition of the parent chemical by agrochemical was also examined when the reaction temperature was room temperature. As a result, when the reaction time is 21 days, the parent substance is N.P. D. It was confirmed that most of the parent substance was decomposed by agricultural chemicals.

[Reference Example 3 (Chlordenes: g-Chlorden)]
<Reference Example 3A (reaction temperature: 70 ° C.)>
Hereinafter, the results of “analysis of chloride ions in the aqueous phase by ion chromatography” and “analysis of intermediates finally present in the oil phase” performed in <Example 3A> will be described. In addition, about the part which does not mention specially, it is the same as that of [Reference example 1]. However, the present inventor has a portion that is currently under intensive study by the inventors.

  FIG. 16 is a graph in which the horizontal axis represents the reaction time and the right vertical axis represents the deCl concentration. The left vertical axis represents each intermediate 1 to 8 calculated from the peak area value corresponding to each intermediate (intermediates 1 to 8), assuming 1 ppm as the parent substance g-chlordane in gas chromatography. The peak area ratio.

<Reference Example 3B (reaction temperature: room temperature)>
In the case where the temperature in the vial was set to room temperature (20 ° C.), similarly to FIG. 16, the horizontal axis represents the reaction time, the right vertical axis represents the deCl concentration, and the left vertical axis represents the peak area ratio of each intermediate. Was obtained (FIG. 17).

<Identification of Intermediate in Reference Example 3>
Furthermore, mass spectrum analysis was performed in order to identify the structures of the intermediates 1 to 8. In this identification, as in [Reference Example 1], RDA was used as a reference.

  The results of mass spectra of g-chlordene (parent substance) itself and each intermediate in this example (chlordane: g-chlordene) will be described below. FIG. 18 is a graph showing the result of the mass spectrum of the parent substance itself. FIGS. 19A to 19D are graphs showing the results of mass spectra of intermediates 1 to 4. FIG. 20A to 20D are graphs showing the results of mass spectra of the intermediates 4 to 6. FIG.

The dechlorination route in which these intermediates 1 to 9 are generated is shown in [Chemical 13] below. Hereinafter, the dechlorination route of this example will be described with reference to this.

Considering Intermediate 1 (FIG. 19A) and Intermediate 2 (FIG. 19B), the presence of cyclopentadiene ions (two chlorines eliminated) and pentachlorocyclopentadiene [C5H1Cl5] ⁺ ( Estimated to be one of (a) of [Chemical Formula 13] in which a total of 5 chlorines were eliminated due to the presence of one chlorine released from hexachlorocyclopentadiene, m / z = 237.7), etc. Is done. In any case, the mass spectra of both are similar. In addition, it is also denied that a total of three chlorines are released (one of the chlorines enclosed by the solid circle in the compound immediately before (a) in [Chemical Formula 13] is released). Can not.

Examination of the intermediate 3 (FIG. 19C) shows that five chlorines have been eliminated due to the presence of cyclopentadiene ions (two chlorines eliminated) and [C5H1Cl3] ⁺ . It is estimated that any one of (a) of the formula 16] is obtained. Note that (b) of [Chemical 13] is the same compound as the intermediate 9 in [Example 2 (heptachlor)], that is, [Chemical 12] (a), and also in the mass spectrum (FIG. 14 (c)). Both are almost identical.

  When the intermediate 4 (FIG. 19D) is studied, six pieces of chlorine are eliminated. From this, intermediate 4 is (b) of [Chemical Formula 13], and it is presumed that 1 chlorine is eliminated from <1> and 1 chlorine is eliminated from <2>.

  When the intermediate 5 (FIG. 20A) is examined, six chlorines are eliminated. From this, it is presumed that the intermediate 5 is (c) of [Chemical 13]. In addition, (c) of [Chemical 13] is the same compound as the intermediate 10 in [Example 2 (heptachlor)], that is, [Chemical 12] (b), and also in the mass spectrum (FIG. 15 (a)). Both are almost identical.

  When the intermediate 6 (FIG. 20B) is examined, seven chlorines are eliminated. From this, it is presumed that the intermediate 5 is (d) of [Chemical Formula 13].

  When the intermediate 7 (FIG. 20 (c)) and the intermediate 8 (FIG. 20 (d)) are examined, seven chlorines are eliminated. Further, taking into consideration that the mass spectra of both are similar to each other, it is presumed that the intermediate 7 and the intermediate 8 are any one of (e) of [Chemical Formula 13].

  As described above, as a result of identifying the intermediate in [Reference Example 3], it was possible to infer that the agrochemical decomposition (dechlorination) pathway in this Example occurred in the pathway as described in [Chemical Formula 13] above. . In addition, the intermediate in the dechlorination route between g-chlordene and (a) in [Chemical 13] could not be confirmed in [Reference Example 3].

  As described above, as described in the embodiments and examples, chlordane as organochlorine pesticide is changed to a state in which microorganisms can be decomposed, so that purification of organochlorine pesticide is simple and short-term. It is possible to provide an organochlorine pesticide degrading agent and a purification method that can prevent harmful and difficult-to-treat by-products from remaining.

Hereinafter, preferred embodiments in this embodiment will be additionally described.
[Appendix 1]
An organochlorine pesticide degrading agent, wherein the porous iron powder contains reduced iron powder and the copper source contains a copper salt, metallic copper or a copper solution.
[Appendix 2]
An organochlorine pesticide decomposer in which mechanical mixing is performed using a pulverizing / mixing device of a type that drives a pulverizing medium in a container such as a vibrating ball mill or a rotating ball mill.
[Appendix 3]
An organochlorine pesticide decomposing agent, wherein the content of copper in the porous copper-containing iron powder is 0.1% by mass to 10% by mass in terms of mass% of the ratio of copper to iron (Cu / Fe).
[Appendix 4]
A purification method that decomposes chlordane followed by microbial decomposition.

Claims (2)

  An organochlorine pesticide degrading agent, comprising a porous copper-containing iron powder obtained by mechanically mixing a porous iron powder and a copper source, and decomposing an organochlorine pesticide containing chlordane.   Soil contaminated with organochlorine pesticides containing chlordane, organochlorine pesticide decomposer containing porous copper-containing iron powder mechanically mixed with porous iron powder and copper source, and organochlorine A purification method characterized by decomposing organochlorine pesticides in contaminated soil and contaminated water by applying to at least one of water contaminated with pesticides.

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