JP3533389B2 - Method of detoxifying dioxins - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detoxification reaction of harmful chlorine compounds represented by dioxins (polychlorodibenzo-p-dioxins, polychlorodibenzofurans ). This is a technique achieved by a reductive dechlorination reaction using metal calcium in alcohol. [0002] A method for dehalogenating dioxins is as follows.
A method using a hydrogenation catalyst such as palladium, a method using an alkali metal such as sodium, a method using a hydride such as lithium aluminum hydride or sodium borohydride, a thermal decomposition method typified by incineration and melt solidification, Methods using critical water, methods of decomposing by laser or electron beam irradiation, bioremediation methods, mechanochemical methods, etc. are known, but the catalyst (metal) used is expensive, anhydrous conditions or high-temperature high-pressure conditions And the operation is complicated, and the processing efficiency (reaction time, dechlorination efficiency, throughput) is inferior. Therefore, it was extremely unsatisfactory as a simple and environmentally friendly reduction method. [0003] Accordingly, an object of the present invention is to provide a novel method for detoxifying dioxins efficiently and efficiently under a mild condition in a short and easy operation. [0004] In order to achieve the above object, the present invention provides a dioxin to be treated first in the form of: Embedded image Wherein X represents chloro group, blanking ROM group, an iodo group. Metallic calcium is added to and mixed with the above chemical formulas (1) and (2) and methanol or ethanol or a mixed solution thereof, and a reaction accelerator based on an organic acid or an organic acid salt is added and mixed with the mixed solution, followed by stirring at room temperature. The method is characterized by a method for detoxifying dioxins. DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the method for detoxifying dioxins of the present invention will be described in detail. The form of dioxins to be treated is not limited to dioxins themselves, but includes dioxins contained in soil, ash and the like. The dioxins are represented by the following general formula (chemical formula). 1, 2) . The above dioxins are represented by the following general formula 1,
2 [0008] [0009] In the formula, X represents a chloro group, a bromo group, or an iodine group, including the case where they are mixed in the same compound. The amount of metal calcium added and mixed to treat 2,000 ng of dioxins (Chemical Formulas 1 and 2) is about 0.1 g to 10 g, and the shape of calcium is not particularly problematic. The above alcohols as the solvent include methanol,
Ethanol Although Le is used, ethanol being most preferred. The reaction temperature is generally selected at room temperature (normal temperature) .
It is stirred at room temperature. In the reaction at room temperature, the reaction accelerator is an organic acid,
Use an organic acid salt (especially a metal calcium salt, but other metal salts may be used). The amount of the reaction accelerator used is desirably 0.2 to 1 times the weight of the added mixed metal calcium. It is desirable to stir during the reaction at room temperature, but it is not always necessary to heat and reflux. The compounds which can be detoxified by the invention, polychlorotrifluoroethylene dibenzo -p- dioxins, polychlorotrifluoroethylene dibenzofurans, and the like odor iodinated dioxins. EXAMPLE 1 Dioxin (1100 ng / ml-hex) was added to a flask.
ane: 22 ng-TEQ / ml-hexane)
ml, metallic calcium (0.8 g) and calcium maleate (0.3 g) were added, and 10 ml of ethanol was added, and the solution was stirred at room temperature for 24 hours. After the reaction,
After 20 ml of ion-exchanged water was added to completely quench the reaction, the concentration of residual dioxins was analyzed by a predetermined dioxin analysis method (GC-MS method). as a result,
The total dioxin concentration was 8.6 ng / ml-hexa
ne: decreased to 0.21 ng-TEQ / ml-hexane. Example 2 Dioxin (1100 ng / ml-hex) was added to a flask.
ane: 22 ng-TEQ / ml-hexane)
ml and metallic calcium (0.8 g) were added, 10 ml of methanol was added, and the solution was stirred at room temperature for 24 hours.
After completion of the reaction, 20 ml of ion-exchanged water was added to completely quench the reaction, and then a predetermined dioxin analysis method (GC-
MS method) to analyze the concentration of residual dioxins. As a result, the total dioxin concentration was 65 ng / m
l-hexane: 0.92 ng-TEQ / ml-he
xane. Example 3 Dioxin (1470 ng, 52 ng-T) was added to a flask.
Metallic calcium (2.7 g) was added to 10 ml of an ethanol solution containing EQ), and this solution was heated under reflux for 24 hours. After completion of the reaction, 20 ml of ion-exchanged water was added to completely quench the reaction, and the residual dioxin concentration was analyzed by a predetermined dioxin analysis method (GC-MS method). As a result, the total amount of dioxins is 11n
g (0.28 ng-TEQ). According to the present invention, dioxins are extracted from soil, ash and / or oil contaminated with dioxins using alcohols, and the extract is easily prepared. There is an effect that the detoxification treatment can be quickly performed. [0023] Further, it is possible to provide a high value-added dioxin treatment method which can be treated at room temperature such as room temperature, and can ensure the safety and economy of the detoxification treatment.

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Claims (1)

(57) [Claims] [Claim 1] The form of dioxins to be treated is Embedded image Wherein X represents chloro group, blanking ROM group, an iodo group. Metallic calcium is added to and mixed with the above chemical formulas (1) and (2) and methanol or ethanol or a mixed solution thereof, and a reaction accelerator based on an organic acid or an organic acid salt is added and mixed with the mixed solution, followed by stirring at room temperature. A method for detoxifying dioxins, which is a feature.