JP2001327982A - Decontamination system for clothing contaminated with pcb - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decontamination system for decontaminating clothing such as a glove, protective clothing or the like contaminated with PCB, which is estimated to be generated in large quantities in the future accompanied by the detoxifying treatment of PCB, to reutilize the same. SOLUTION: The decontamination system for clothing contaminated with PCB has an organic solvent washing means 1 for washing the clothing contaminated with PCB with an organic solvent, a hot water washing means 2 for washing the clothing, which is washed with the organic solvent, with hot water, a dehydration drying means 3 for dehydrating and drying the clothing washed with hot water and a supercritical water oxidizing and decomposing means 4 for subjecting the PCB-containing discharge liquids discharged from the hot water washing means 2 and the dehydration drying means 3 to supercritical water oxidizing and decomposing treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for decontaminating and reusing clothing such as gloves and protective clothing contaminated with PCB.

[0002]

2. Description of the Related Art PCBs have been widely used as insulating materials for electric devices such as capacitors and transformers because of their excellent heat resistance, chemical stability and insulating properties.
However, PCB is highly toxic, and is one of the most common in Japan.
In 972, production, import and use were banned in principle.

[0003] PC extracted from electrical equipment such as a transformer
As a method for treating PCB contaminants such as paper and wood contaminated with B and PCBs, the United States Environmental Protection Agency (EP)
The method of incineration in an incinerator approved by A) is adopted. However, harmful substances such as dioxin may be generated during incineration.
There is no incineration of B contaminants.

[0004] Therefore, in Japan at present, electrical equipment such as transformers and capacitors filled with PCBs are only strictly stored as specially managed industrial wastes.
Further, at present, PCB detoxification is hardly performed. However, it cannot be said that storage is always performed strictly, and there is concern about environmental pollution from stored PCBs. Therefore, safe and efficient electrical equipment such as transformers and capacitors filled with PCBs is urgently targeted. There is a demand for a detoxification process for PCBs.

[0005]

SUMMARY OF THE INVENTION However, PCB
When the detoxification process goes on track, it is expected that gloves, protective clothing and the like contaminated with PCB will be generated in large quantities.

The problem to be solved by the present invention is that the PCB
It is an object of the present invention to provide a system for decontaminating and reusing clothing such as gloves and protective clothing contaminated with PCB, which is expected to be generated in large quantities in the future due to the detoxification process.

[0007]

According to the first aspect of the present invention, there is provided an organic solvent cleaning means for cleaning gloves, protective clothing, and the like contaminated with PCB with an organic solvent. Hot water washing means for washing gloves, protective clothing, etc. washed with hot water, dehydration drying means for dehydrating and drying gloves, protective clothing, etc. washed with hot water, organic solvent washing means, hot water washing means, and dehydration drying means. Gloves contaminated with PCB, comprising supercritical hydroxylation decomposition means for supercritical hydroxylation decomposition of the discharged liquid containing PCB.
The present invention relates to a decontamination system for protective clothing and the like.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The clothes contaminated with PCB to be treated according to the present invention include gloves, protective clothing, work clothes, protective aprons, towels, and rags contaminated with PCB during the PCB decontamination and decomposing work. , Hats, etc., which can be reused by decontamination.

In the decontamination system of the present invention, first, PCB contaminated gloves, protective clothing, and the like are washed by organic solvent washing means, and the PCB soaked in the clothes is removed. As the organic solvent used in the organic solvent cleaning means, the solubility of PCB is large and the boiling point temperature is significantly lower than that of PCB.
And the solvent can be easily separated by the difference in boiling point temperature.
Trichloroethylene and tetrachloroethylene are preferred.

As the organic solvent cleaning means, a known mechanical cleaning device and a known ultrasonic cleaning device can be used.

In order to remove the residual organic solvent from the washed clothes by the organic solvent washing means, the organic solvent is discharged and then washed with hot water by hot water washing means.

After washing with warm water by means of washing with warm water, the clothes are dehydrated by means of dehydrating and drying and dried to form a PC.
Gloves, protective clothing, etc. decontaminated with B can be obtained and can be reused.

The above-mentioned organic solvent washing means, hot water washing means and dehydration / drying means may use independent washing machines and dehydration / drying machines, but use a single apparatus having washing / dehydration / drying functions. Is also good.

The organic solvent or warm water discharged from the organic solvent washing means, hot water washing means and dehydration / drying means contains PCB.
Is contained, so that a supercritical hydroxylation decomposition treatment is performed by a supercritical hydroxylation decomposition means. PCB is completely decomposed into carbon dioxide, water, and chlorine by supercritical hydroxylation and detoxification.

As the supercritical hydroxylation decomposition means, a known means may be employed. Examples of the supercritical water oxidation decomposition means include a supercritical water oxidation decomposition apparatus equipped with a reactor for oxidatively decomposing organic substances in the presence of supercritical water and an oxidizing agent. The supercritical hydroxylation decomposition reaction performed in the reactor is not particularly limited as long as the temperature and pressure conditions bring water to a supercritical state. For example, the temperature is 374 ° C. or higher, preferably 550 to 650 ° C. And pressure 22MPa
As described above, preferably, the condition is 22 to 25 MPa. Examples of the oxidizing agent include air, pure oxygen, hydrogen peroxide, and liquid oxygen. These oxidizing agents may be used in a stoichiometrically required amount or more. The reactor for performing the supercritical hydroxylation decomposition may be any of a pipe (tubular) type and a vessel type. When performing supercritical hydroxylation decomposition of PCB, an auxiliary fuel such as isopropyl alcohol may be used as necessary. The recovered PCB, water (pure water) and oxidizing agent may be pressurized to a predetermined pressure by a compressor or the like, sent to a reactor, and subjected to a supercritical hydroxylation decomposition reaction.

Since water becomes a good solvent in the supercritical state, supercritical water, organic matter and oxidizing agent form a homogeneous phase in the reactor, and the supercritical water oxidation reaction proceeds, and the reaction time is extremely short. Over time, the PCB is oxidatively decomposed.

The PCB is completely decomposed by the supercritical hydroxylation decomposition reaction to generate chloride ions. Therefore, an alkali such as sodium hydroxide is added to convert the chloride ions in the processing fluid into chlorides such as sodium chloride. Is preferred.

An embodiment of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1 is a flowchart for explaining an embodiment of the system of the present invention.

The gloves, protective clothing and the like contaminated with PCB are washed by the organic solvent washing means 1. By the washing process, the PCB soaked in the clothes is dissolved in the organic solvent, and P is removed from the clothes.
CB is decontaminated. The organic solvent in which PCB is dissolved is subjected to a supercritical hydroxylation decomposition treatment by a supercritical hydroxylation decomposition means 4 described below.

After washing with the organic solvent washing means 1, the organic solvent is discharged, centrifugally dehydrated, and then washed with hot water washing means 2. By washing with warm water, trace amounts of organic solvents remaining in clothes can be removed from gloves, protective clothing, and the like. The hot water discharged from the hot water washing means 2 is subjected to a supercritical hydroxylation decomposition treatment by a supercritical hydroxylation decomposition means 4 described later.

The clothes washed with hot water are dehydrated and dried by the dehydrating and drying means 3. Clothes after drying are PCB
Has been decontaminated and can be reused.
The discharged liquid discharged at the time of dehydration is subjected to a supercritical hydroxylation decomposition treatment by a supercritical hydroxylation decomposition means 4 described later.

The effluent discharged from the organic solvent washing means 1, the hot water washing means 2 and the dehydration / drying means 3 is subjected to supercritical hydration decomposition by the supercritical hydration decomposition means 4. Pure water and an oxidizing agent may be added to the effluent, an auxiliary fuel may be added if necessary, and a supercritical hydroxylation decomposition reaction may be performed at a pressure and temperature under which water becomes supercritical. The PCB is rapidly decomposed into water, carbon dioxide, and chloride ions by the supercritical hydroxylation decomposition, and the chloride ions are neutralized by an alkali to form chlorides. The processing fluid after the supercritical hydroxylation decomposition is cooled by a cooler (not shown) and is separated into gas and liquid.

In FIG. 1, the organic solvent in which the PCB discharged from the organic solvent washing means 1 is dissolved is directly sent to the supercritical oxidative decomposition means 4 to perform the supercritical oxidative decomposition treatment. The dissolved organic solvent is distilled to recover the solvent, the recovered solvent is used again in the organic solvent washing means 1, and the residue containing PCB remaining by distillation is fed to the supercritical hydroxylic decomposition means 4. Supercritical oxidative decomposition treatment is acceptable.

[0025]

According to the present invention, PCBs can be decontaminated and detoxified from clothes contaminated with PCBs, and the decontaminated clothes can be reused. Since PCB is subjected to a supercritical hydroxylation decomposition treatment, no harmful by-products such as dioxin are generated during detoxification.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an embodiment of the present invention.

[Explanation of symbols]

 1 Organic solvent washing means 2 Hot water washing means 3 Dehydration drying means 4 Supercritical hydroxylation decomposition means

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C07B 35/06 C07C 25/18 37/06 B09B 3/00 ZAB C07C 25/18 304Z F term (reference) 2E191 BA13 BB00 BC01 BC05 BD11 3B201 AA46 BB03 BB82 BB92 BB95 CB11 CC13 CD22 4D004 AA50 AB06 BA10 CA36 CA39 CA40 CC02 CC03 CC15 4D050 AA12 AB19 BB01 BB09 BC01 BC02 BD06 CA05 4H006 AA05 AC13 BB31 BC10 BC11 BE30 BE33 BE60 EA22

Claims (1)

[Claims] 1. An organic solvent washing means for washing clothes contaminated with PCB with an organic solvent, a warm water washing means for washing clothes washed with an organic solvent with warm water, and a dehydrator for dehydrating and drying the clothes washed with hot water. Drying means, and P discharged from the organic solvent washing means, hot water washing means and dehydration drying means
A decontamination system for clothes contaminated with PCB, comprising supercritical hydroxylation decomposition means for supercritically hydrolyzing effluent containing CB.