JP2005211408A - Treatment method and apparatus for residue of agricultural chemical - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a treatment method and apparatus for residue of agricultural chemicals reducing the generation of secondary pollutant, safely retaining working environment and suitably decomposing organic halogens such as organochlorine compounds in solid-state agricultural chemicals without being left in the solid-state agricultural chemicals in the so-called residue of agricultural chemicals buried underground after prohibiting its use or being stored and left in a farmhouse. <P>SOLUTION: This treatment method is characterized in that the solid-state residue of agricultural chemicals including halogenated compounds are dehalogenated by alkali metal, and treated objects after the dehalogenation are distilled under a reduced-pressure or vacuum-dried to remove the halogenated compounds from the treated objects. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method and apparatus for treating residual agricultural chemicals used, and more specifically, a so-called residual agricultural chemical used that is buried in the soil after being prohibited from use or left stored in a farmhouse. In particular, the present invention relates to a solid pesticide treatment method and apparatus.

  Conventionally, pesticides containing organic halogens such as organic chlorine compounds such as DDT, hexachlorocyclohexane (BHC), and hexachlorobenzene (HCB) have been widely used because of their excellent pest control effects. Residual or bioconcentration causes these drugs to behave in a manner similar to the original biohormones, demonstrating a significant impact on the ecosystem, such as loss of normal reproductive function (environmental hormones, endocrine disruptors, etc.) Currently, its use is prohibited. Since the use of these pesticides has been banned, the remaining ones are buried in the soil, left as they are stored by farmers, or collected and stored by pesticide manufacturers. These pesticides are also called residual agricultural chemicals.

  Among these residual agricultural chemicals, those that are stored at farms or collected by manufacturers, but those that are buried in the soil and left for many years may cause environmental damage depending on the storage conditions, The impact on the ecosystem cannot be ignored.

  Therefore, in recent years, residual agricultural chemicals that have been buried in the soil and left for many years have been dug up and treated. These organohalogen pesticides are contained in persistent organic pollutants and are required to be treated systematically by the Stockholm Convention adopted in May 2001. Recently, in addition to conventional DDT and BHC, PCNB (polychlorinated nitrobenzene) has also been banned, and the demand for treatment of these residual agricultural chemicals has become increasingly strong.

In the case of treating such residual agricultural chemicals, a method of incineration has been conventionally employed as shown in Patent Document 1 and Patent Document 2 below.
JP2003-284920A JP 2001-70470 A

  However, incineration of agricultural chemicals containing halogen compounds such as chlorine has the problems that the furnace life is shortened by halogens such as chlorine, and that secondary contaminants such as dioxins may be generated. there were. In addition, when treating agricultural chemicals stored at farms or agricultural chemicals collected by manufacturers, there is a problem of generation of dioxins due to inevitable use of incineration means.

Therefore, in order to decompose the agricultural chemical that is a chlorine compound without such incineration, a technique such as the following Patent Document 3 that decomposes the agricultural chemical made of a chlorine compound with an alkali metal such as sodium has been developed.
In this technology, in order to treat organochlorine compounds such as polychlorinated biphenyls, the organochlorine compounds are decomposed and treated with alkali metals to dechlorinate the organochlorine compounds. It can be applied.
Japanese Patent Laid-Open No. 9-25118

  However, in the case of pesticides, there are solid properties that are supported on inorganic auxiliary agents such as clay minerals, extenders, etc., and the pesticides having such properties are utilized using the technique described in Patent Document 3 above. When an attempt is made to treat, the organochlorine compound may remain in the treatment residue even after the organochlorine compound, which is a component in the agricultural chemical, is dechlorinated with an alkali metal.

  The present invention was made in order to solve all the problems as described above, and the occurrence of secondary contaminants is small, the working environment can be kept safe, and the organic chlorine compounds in the solid agricultural chemicals, etc. It is an object of the present invention to provide a method and an apparatus for treating residual agricultural chemicals that can be suitably decomposed without remaining the organic halogen in solid agricultural chemicals.

The present invention has been made in order to solve such problems, and the invention according to claim 1 is a method for treating residual agricultural chemicals used, wherein a solid residual agricultural chemical containing a halogen compound is treated with an alkali metal. A dehalogenation treatment is performed, and the object to be treated after the dehalogenation treatment is subjected to vacuum distillation or vacuum drying to remove a halogen compound from the object to be treated.
Further, the invention according to claim 2 is that a solid residual agricultural chemical containing a halogen compound is dehalogenated with an alkali metal, and the dehalogenated material to be treated is distilled under reduced pressure, and then treated residue, treatment It is characterized by being separated into water and treated oil.

  Further, the invention according to claim 3 is that the solid residual agricultural chemicals containing a halogen compound are dehalogenated with an alkali metal, and the treated material after the dehalogenation treatment is separated into filtration residue, treated water, and treated oil. After that, the filtration residue is vacuum-dried. Further, the invention according to claim 4 is characterized in that in the method for treating residual agricultural chemicals according to any one of claims 1 to 3, the solid residual agricultural chemicals are pulverized before the dehalogenation treatment.

  Further, the invention according to claim 5 is a treatment apparatus for residual agricultural chemicals used, wherein the solid residual agricultural chemicals containing a halogen compound are decomposed with an alkali metal to be dehalogenated, and the dehalogenation treatment apparatus. A vacuum distillation apparatus that distills the object to be treated that has been dehalogenated by the halogenation apparatus, and a separation apparatus that separates the object that has been distilled under reduced pressure by the vacuum distillation apparatus into a treatment residue, treated water, and treated oil. It is characterized by comprising.

  Furthermore, the invention according to claim 6 is a dehalogenation treatment device for decomposing and dehalogenating a solid residual agricultural chemical containing a halogen compound with an alkali metal, and a dehalogenation treatment by the dehalogenation treatment device. A separation device that separates the processed material into filtration residue, treated water, and treated oil, and a vacuum drying device that vacuum-drys the filtration residue separated by the separation device.

  Furthermore, the invention according to claim 7 is the treatment apparatus for residual agricultural chemicals according to claim 5 or 6, further comprising a pulverizer for pulverizing the solid residual agricultural chemicals before the dehalogenation treatment. .

  As described above, the present invention is a method of dehalogenating a solid residual agricultural chemical containing a halogen compound with an alkali metal, and subjecting the treated product after the dehalogenated treatment to reduced-pressure distillation or vacuum drying. Since the halogen compound is removed, there is an effect that the halogen compound does not remain in the treated residue.

  In addition, when the solid residual agricultural chemicals are pulverized before the dehalogenation treatment, the reaction between the alkali metal and the halogen compound is likely to occur during the subsequent dehalogenation treatment with an alkali metal. The possibility that the halogen compound remains in the solid residual agricultural chemical used is further reduced, and there is an effect that the dehalogenation treatment can be performed more suitably.

(Embodiment 1)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, a processing apparatus for residual agricultural chemicals as one embodiment will be described. As shown in FIG. 1, the processing apparatus for residual agricultural chemicals of this embodiment includes a pulverizing apparatus 1, a dechlorination apparatus 2, a vacuum distillation apparatus 3, a hydration tank 4, and a separation apparatus 5. Has been.

  The pulverizing apparatus 1 is an apparatus for pulverizing solid residual agricultural chemicals. As the pulverizing apparatus 1, intermediate crushers such as a jaw crusher and a gyratory crusher, a cone crusher, a double roll crusher, and a hammer mill are used. A fine pulverizer such as a pulverizer, a ball mill, a rod mill and a pin mill, and an ultrafine pulverizer such as a jet mill and a colloid mill can be used. However, it is preferable to use a fine pulverizer such as a ball mill, a rod mill, or a pin mill.

  The pulverization treatment mode can be either dry pulverization or wet pulverization, but in dry pulverization, fine particles adhere to the wall or ball of the pulverizer to form a coating layer. In consideration of the point that it cannot be pulverized more finely than the diameter, wet pulverization is preferable. In addition, in the case of a wet type, it is preferable because scattering of fine powder can be prevented.

  The dechlorination apparatus 2 is an apparatus for dechlorinating organochlorine compounds in agricultural chemicals pulverized by the pulverization apparatus 1. In the dechlorination apparatus 2, sodium in which metallic sodium is dispersed in insulating oil. The dispersion is added, and the organic chlorine compound is decomposed. The dechlorination apparatus 2 has a structure in which a stirring blade 7 is provided in the apparatus main body 6 as shown in FIG. As shown in the figure, the agitating blade 7 has a configuration in which paddle blades 10a, 10b are vertically attached to two upper and lower stages of a rotating shaft 9 driven by a motor 8, and the upper and lower paddle blades 10a. , 10b are not clearly shown, but are arranged at a 45 degree crossing angle. The dechlorination apparatus 2 is purged with nitrogen gas to form a nitrogen atmosphere.

The vacuum distillation apparatus 3 is an apparatus for vacuum distillation of the solids dechlorinated by the dechlorination apparatus 2, and the solids are vacuum distilled by the vacuum distillation apparatus 3, so that the solids The oil (hydrocarbon) contained in the gas evaporates, but a condensing device 11 is further provided for condensing the evaporated oil.
The hydration tank 4 is for hydrating the sodium dispersion that has not been consumed in the dechlorination apparatus 2, and water is added to the hydration tank 4.

The separation device 5 is for separating the hydrated material into filtration residue, treated oil, and treated water. Carbon dioxide gas is added to the separation device 5 in order to neutralize the alkali generated by the hydration reaction in the hydration tank 4. An activated carbon treatment device 12 for purifying the treated water after separation is provided on the rear side of the separation device 5.
Further, an activated carbon treatment device 13 is provided for adsorbing the agricultural chemical component in the exhaust gas generated from the dechlorination device 2 and the agricultural chemical component in the exhaust gas generated by being separated from the oil component by the condensing device 11.

Next, a method for treating the residual agricultural chemical using the residual residual agricultural chemical treatment apparatus as described above will be described.
First, solid residual agricultural chemicals are supplied to the pulverizer 1. This solid residual agricultural chemical is a solid agricultural chemical buried in the soil, a solid agricultural chemical that has been stored in a farmhouse, or a solid agricultural chemical recovered by the manufacturer. However, both remain and require processing.

  In this case, the agrochemicals stored and left by the farmers and the pesticides collected by the manufacturer are supplied to the crushing device 1 as they are, but the residual agricultural chemicals in the soil are packed in a plastic bag etc. Since the container is buried and filled in the hollow part of a concrete pipe that has been buried in the ground in advance, the residual agricultural chemicals in such a state are dug out of the soil, vinyl After separating from bags, containers, concrete waste, soil, etc., solid agricultural chemicals are supplied to the pulverizer 1 as described above.

  The solid residual agricultural chemicals supplied to the pulverizer 1 are pulverized by the pulverizer 1. If pulverization is performed in this way, organochlorine compounds in agricultural chemicals are more easily decomposed in the subsequent dechlorination step, the overall treatment time is shortened, and the degree of detoxification of organochlorine compounds is improved. Can be made. Further, the pulverizer 1 is supplied with hydrocarbon as a solvent. This solvent will extract a certain amount of chlorine compounds from solid agricultural chemicals. In this embodiment, an aliphatic hydrocarbon such as normal paraffin or isoparaffin is used as the solvent.

  The used residual agricultural chemicals pulverized in this way are supplied to the dechlorination apparatus 2. Then, in the dechlorination apparatus 2, the organic chlorine compound is decomposed by the metallic sodium in the metallic sodium dispersion. That is, a sodium dispersion in which metallic sodium is dispersed in insulating oil is added to the dechlorination apparatus 2, and the metallic sodium in the sodium dispersion reacts with the organic chlorine compound in the pulverized solid agricultural chemical. Organic chlorine compounds are dechlorinated and decomposed.

  Next, the used residual agricultural chemicals thus dechlorinated is supplied to the vacuum distillation apparatus 3. In the vacuum distillation apparatus 3, the solid matter subjected to the dechlorination treatment is distilled under reduced pressure. As the solid matter is distilled under reduced pressure in this way, the oil (hydrocarbon) contained in the solid matter is evaporated, supplied to the condensing device 11, and condensed by the condensing device 11. The condensed oil condensed is returned to the pulverizing apparatus 1 and reused as a solvent, or returned to the dechlorination apparatus 2 and reused as a solvent for residual agricultural chemicals.

  Here, the organic chlorine compound contained in the solid is supposed to be decomposed by the dechlorination apparatus 2 originally, but the residual agricultural chemicals to be treated are solid. The dechlorination apparatus 2 may not be completely decomposed and may remain in the solid residual agricultural chemicals. However, the organic chlorine compound is removed from the solid by being distilled under reduced pressure in the vacuum distillation apparatus 3, and as a result, extracted into the oil that evaporates.

  Next, excess metallic sodium not consumed in the dechlorination apparatus 2 is supplied to the hydration tank 4 via the vacuum distillation apparatus 3. The hydration tank 4 is also supplied with a solid material that has been subjected to vacuum distillation by the vacuum distillation apparatus 3 to remove oil (hydrocarbon). Then, water is supplied to the hydration tank 4 and the unconsumed metallic sodium is hydrated. In this hydration tank 4, alkali is generated by the hydration reaction of metallic sodium, and thus the hydrated material to be treated is supplied to the separation device 5 and neutralized. That is, carbon dioxide gas is supplied to the separation device 5, and the carbon dioxide gas reacts with the alkali to be neutralized.

  The to-be-processed material neutralized by the separation device 5 is separated into solid content (filter residue), oil content, and moisture. The separated filtration residue is recovered as a processing residue, the oil is recovered as a processing oil, and the water is supplied to the activated carbon treatment device 12 as a treated water.

  In this case, since the solids constituting the treated residue after the recovery are distilled under reduced pressure in the vacuum distillation apparatus 3, they are not completely decomposed by the dechlorination apparatus 2 and remain in the solid residual agricultural chemicals. The chlorinated organic compound is also extracted into the solvent evaporated by the vacuum distillation apparatus 3, and as a result, the chlorinated organic compound remaining in the solid is removed by the vacuum distillation apparatus 3. Become. Therefore, the organochlorine compound does not remain in the collected treatment residue.

  Moreover, even if a small amount of organochlorine compound is contained in the treated water, the activated carbon treatment device 12 adsorbs the organochlorine compound in the treated water on the activated carbon, and only the treated water containing no organochlorine compound is used as waste water. It will be discharged out of the system. The recovered treated oil can be reused as a solvent.

  Further, the oil component evaporated by the vacuum distillation device 3 and supplied to the condensing device 11 is condensed by the condensing device 11 as described above, and returned to the pulverizing device 1 or the dechlorination device 2 for reuse. The exhaust gas is removed from the oil condensed by the condensing device 11, and the exhaust gas is supplied to the activated carbon treatment device 13. Therefore, even if a small amount of organochlorine compound is contained in the oil component supplied to the condenser 11, the organochlorine compound is adsorbed on the activated carbon of the activated carbon treatment device 13, and does not contain an organochlorine compound. Only water will be discharged out of the system.

  Further, the exhaust gas from the dechlorination apparatus 2 is also supplied to the activated carbon treatment apparatus 13. Even if a small amount of organic chlorine compound is contained in the exhaust gas from which the organic chlorine compound is decomposed and removed by the dechlorination apparatus 2, the organic chlorine compound is adsorbed on the activated carbon of the activated carbon treatment apparatus 13 and is organically Only the exhaust gas containing no chlorine compound is discharged outside the system.

  As described above, in the present embodiment, the organic chlorine compound is removed from the solid together with the oil by being distilled under reduced pressure in the vacuum distillation apparatus 3, and therefore, the solid used residual agricultural chemical is used as the treatment target. Nevertheless, there is no possibility that the organochlorine compound remains in the treatment residue finally recovered.

(Embodiment 2)
In this embodiment, a vacuum drying device 14 is used instead of the vacuum distillation device 3 of the first embodiment. The vacuum distillation apparatus 3 according to the first embodiment is provided at the rear stage of the dechlorination apparatus 2 and at the front stage of the hydration tank 4, whereas the vacuum drying apparatus 14 according to the present embodiment is as shown in FIG. , Provided in the subsequent stage of the separation device 5.

  Therefore, in this embodiment, the solid substance dechlorinated by the dechlorination apparatus 2 is immediately supplied to the hydration tank 4 without being distilled under reduced pressure as in the first embodiment. The point where water is supplied to the hydration tank 4 and unconsumed metallic sodium is hydrated, the object to be treated after hydration is neutralized by the separation device 5, and the treatment to be neutralized by the separation device 5 The point by which a thing is isolate | separated into solid content (filtration residue), oil content, and a water | moisture content is the same as that of the case of Embodiment 1.

  In this embodiment, the filtration residue separated by the separation device 5 is not immediately recovered as a processing residue, but is supplied to the vacuum drying device 14 and vacuum dried. As described above, since the filtration residue is separated from the oil by the separation device 5, the filtration residue should not originally remain in the oil, but by being vacuum dried by the vacuum drying device 14 as described above, The oil remaining in the filtration residue is evaporated and supplied to the condenser 11.

  The oil component supplied to the condensing device 11 is condensed and returned to the dechlorination device 2 for reuse. In this case, the organic chlorine compound contained in the solid is supposed to be decomposed by the dechlorination apparatus 2 as in the case of the first embodiment. Even if it remains in the pesticide, it is separated from the filtration residue by the separation device 5 and extracted to the treated oil side. Furthermore, even if an organochlorine compound remains in the filtration residue without being separated by the separation device 5, it is extracted to the evaporated oil side by being vacuum dried by the vacuum drying device 14. . Therefore, there is no possibility that the organochlorine compound remains in the treatment residue after vacuum drying.

  Further, exhaust oil is removed from the oil component condensed by the condenser 11 as in the case of the first embodiment, and the exhaust gas is supplied to the activated carbon treatment device 13. As a result, even if the organochlorine compound remains in the oil component supplied to the condensing device 11, it is adsorbed on the activated carbon of the activated carbon treatment device 13 in the same manner as in the first embodiment, and does not contain an organochlorine compound. Only will be released out of the system.

  The oil component separated by the separation device 5 is recovered as treated oil, and the water is supplied as treated water to the activated carbon treatment device 12 as in the case of the first embodiment.

  Also in the present embodiment, since the solids constituting the processing residue after collection are vacuum-dried by the vacuum drying device 14, they are not completely decomposed by the dechlorination device 2 and are in solid use residual agricultural chemicals. The organochlorine compound remaining in the solvent is also extracted into the solvent evaporated by the vacuum dryer 14, and the organochlorine compound remaining in the filtration residue separated by the separator 5 is removed from the vacuum dryer 14. Will be removed. Therefore, also in this embodiment, the organic chlorine compound does not remain in the collected processing residue.

(Other embodiments)
In the above embodiment, aliphatic hydrocarbons such as normal paraffin and isoparaffin are used as the solvent. However, the type of solvent is not limited to this, and kerosene, kerosene-derived solvent, etc. can also be used. It is.
In terms of extracting an organic chlorine compound, alcohol solvents such as isopropyl alcohol, ethanol, and methanol, ketone solvents such as acetone, ether solvents such as ethyl ether, and the like can be used. In addition, aromatic hydrocarbons such as toluene, xylene and alkylbenzene, and alicyclic hydrocarbons such as cyclohexane can also be used.

  However, since the alcohol solvent, ketone solvent and ether solvent react with the alkali metal, the alkali metal is inadvertent when supplied to the dechlorination apparatus 2 even if the organic chlorine compound can be extracted. There is a problem of being consumed. Aromatic hydrocarbons and alicyclic hydrocarbons are not preferable because when the surplus alkali metal is hydrated in the hydration tank 4, the solvent is eluted into the water tank and wastewater treatment is required.

  Therefore, in consideration of these points, it is desirable to use the aliphatic hydrocarbons, kerosene, kerosene-derived solvents and the like as described above. In this case, it is preferable to use a boiling point in the range of 100 to 300 ° C. Incidentally, the boiling point of normal paraffin is about 171 to 227 ° C, and the boiling point of kerosene is about 150 to 270 ° C.

  Furthermore, the temperature at which the organochlorine compound separated from the agricultural chemical in the dechlorination apparatus 2 is reacted with the sodium dispersion is not particularly limited, but is preferably about 30 to 100 ° C. The ratio of the alkali metal to chlorine is preferably about 1 to 10 mol when the contaminated oil obtained by extracting the organic chlorine compound with a solvent is high, and preferably about 10 to 1000 mol when the concentration is low.

  Furthermore, although the sodium metal used as what makes the decomposition | disassembly reaction of an agrochemical in the dechlorination apparatus 2 of the said embodiment has an advantage which is cheap and generally easily available, it is not restricted to this, Metal potassium, Metal strontium, It is also possible to use metallic lithium or an alloy thereof. That is, a dispersion in which an alkali metal is dispersed in a dispersion medium such as oil may be used.

Furthermore, the kind of agricultural chemicals used in the present invention is not limited to any kind such as PCNB (polychlorinated nitrobenzene), DDT, and BHC. In addition, the properties of the agrochemicals are, for example, those obtained by attaching agrochemicals to a bulking agent such as bentonite and clay to form granules, powders, etc. Any property is not required. In short, it may be solid.
Furthermore, although the said embodiment demonstrated the case where the agrochemical containing an organic chlorine compound was processed, it is also possible to apply this invention to the treatment of the agrochemical containing organic halogen compounds other than chlorine.

  In the present invention, the “agrochemical containing an organic halogen compound” means that, for example, when the agrochemical is granular, it contains a bulking agent in addition to the original medicinal ingredients such as PCNB, DDT, BHC, etc. In the case of powders, about 90% of inorganic assistants are included to facilitate dissolution and dispersion during spraying, and the whole including these inorganic assistants and extenders is agricultural chemicals. This means that only the portion is an organic halogen compound.

  A PCNB preparation, a diluting hydrocarbon (normal paraffin type), and isopropyl alcohol (IPA) were placed in a reaction tank for dechlorination, and the liquid to be treated was prepared by stirring and mixing. The reaction tank was purged with nitrogen gas, and the exhaust gas was sampled until the end of the reaction. While controlling the liquid to be treated at a reaction temperature of 180 ° C., a metal sodium dispersion was injected into the reaction tank to carry out a dechlorination reaction.

  After the injection of the liquid to be treated is completed, hold the reaction solution at 180 ° C, sample the reaction solution after 15 minutes, 60 minutes, and 180 minutes, and measure the concentration of residual PCNB in the reaction solution to decompose PCNB. After confirming this, the reaction solution was cooled to 40 ° C. or lower.

  After completion of the reaction, the reaction liquid cooled to 40 ° C. or lower was transferred to a hydration tank, and stirred and mixed with water to hydrate excess sodium. After hydration, solid-liquid separation was performed by filtration, and the filtration residue was dried with a vacuum drying apparatus at 240 ° C. and 100 Pa or less for 3 hours to obtain a treatment residue. The filtrate was allowed to stand and separated into treated oil and hydrated water. Hydrated water was neutralized with carbon dioxide gas to obtain treated water.

And the amount of PCNB in processing residue, processing oil, and processing water was measured. The results are shown in Table 1.

  As is apparent from Table 1, when the amount of PCNB subjected to the reaction was 100%, the PCNB decomposition rate was 99.9999% or more.

  The used residual agricultural chemical treatment method and apparatus of the present invention are agricultural chemicals that remain in the soil or are stored as they are, and can be applied to solid agricultural chemicals.

The schematic block diagram of the processing apparatus of the residual pesticide used as one Embodiment. FIG. The schematic front view of the dechlorination apparatus in a processing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Grinding device 2 ... Dechlorination device 3 ... Vacuum distillation device 14 ... Vacuum device

Claims (7)

  It is characterized by dehalogenating a solid residual agricultural chemical containing a halogen compound with an alkali metal, and removing the halogen compound from the object to be treated by distillation under reduced pressure or vacuum drying. A method for treating residual agricultural chemicals.   The solid residual agricultural chemicals containing halogen compounds are dehalogenated with alkali metals, and after the dehalogenated material is distilled under reduced pressure, it is separated into treated residue, treated water, and treated oil. A method for treating residual agricultural chemicals.   The solid residual agricultural chemicals containing halogen compounds are dehalogenated with alkali metals, and the treated material after dehalogenation is separated into filtration residue, treated water, and treated oil, and then the filtration residue is vacuum dried. A method for treating residual agricultural chemicals.   The method for treating residual agricultural chemicals according to any one of claims 1 to 3, wherein the solid residual agricultural chemicals are pulverized before the dehalogenation treatment.   A dehalogenation treatment apparatus that decomposes a solid residual agricultural chemical containing a halogen compound with an alkali metal and dehalogenates, and a reduced pressure at which an object to be treated dehalogenated by the dehalogenation treatment apparatus is distilled under reduced pressure. An apparatus for treating residual agricultural chemicals comprising a distillation apparatus and a separation apparatus for separating solids distilled under reduced pressure in the vacuum distillation apparatus into treated residues, treated water, and treated oil.   A solid-state residual agricultural chemical containing a halogen compound is decomposed with an alkali metal and dehalogenated, and a dehalogenated treatment apparatus that is dehalogenated with the dehalogenation treatment apparatus is filtered, An apparatus for treating residual agricultural chemicals comprising a separator for separating treated water and treated oil, and a vacuum dryer for vacuum drying the filtration residue separated by the separator.   The used residual agricultural chemical treatment apparatus according to claim 5 or 6, further comprising a pulverizer for pulverizing the solid residual residual agricultural chemical before the dehalogenation treatment.