JPH0475024B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for immobilizing liquid organic halides (including chlorides and bromides) such as PCBs to make them pollution-free, and a treatment agent used for the immobilization process. Liquid organic halides such as PCBs (polychlorinated biphenyl) are extremely stable compounds and are also toxic, making their disposal extremely difficult. Conventionally, incineration has been used to decontaminate liquid organic halides, but since organic halides are in liquid form,
It is difficult to handle, and if it is stored in a drum or the like, there is a risk of causing a great deal of pollution if a natural disaster occurs and the drum breaks and spills out. The present invention was made in order to solve the problems encountered in the disposal of such liquid organic halides. That is, according to the present invention, calcium oxide and/or
Or, when causing an exothermic reaction between magnesium oxide and water, the reaction is carried out together with a liquid organic halide,
The process is carried out in the presence of a water-soluble polymer containing a hydroxyl group and/or a carboxyl group, an organic acid metal, a silicate, and an inorganic filler to finally obtain a solid substance in which a liquid organic halide is immobilized. A method for immobilizing a liquid organic halide is provided. In the present invention, when fixing a liquid organic halide, an exothermic reaction between calcium oxide and/or magnesium oxide and water is utilized. It is well known that calcium oxide and magnesium oxide react with water to generate a large amount of heat. The present invention is characterized by the presence of a liquid organic halide in this exothermic reaction system, as well as the presence of a water-soluble polymer, an organic acid metal salt, a silicate, and an inorganic filler. Various conventionally known water-soluble polymers containing hydroxyl and/or carboxyl groups are used, including cellulose derivatives such as polyvinyl alcohol, starch and its derivatives, methoxycellulose, hydroxyethylcellulose, methylcellulose, ethylcellulose, and carboxymethylcellulose. , sodium polyacrylate, styrene/maleic anhydride copolymer alkali salt, sodium alginate, gelatin, casein, etc. Such water-soluble polymers contain many hydrophilic groups such as carboxyl groups and hydroxyl groups in their molecules, and under the alkaline conditions of the present invention, they react with organic halides and silicates, or become gel-like substances, resulting in It is thought that the substance is converted into a water-insoluble substance. As the organic acid metal salt, various conventionally known aliphatic and aromatic ones having a carboxyl group are used, such as stearic acid, capric acid, lauric acid, myristic acid, palmitic acid, linoleic acid, and linolenic acid. , metal salts of higher fatty acids such as oleic acid, and aromatic carboxylic acids such as benzoic acid, salicylic acid, p-hydroxybenzoic acid, naphthoic acid, and tannic acid. Further, examples of metal salts include aluminum, manganese, cobalt, calcium, magnesium, iron, zinc, and nickel. In the present invention, it is preferable to use organic acid metal salts that are generally used as metal soaps. Such organic acid metal salts are water-insoluble, have the effect of making the product produced after the reaction into a smooth powder, and also form coordination bonds with organic halogen compounds and the above-mentioned polymers, and form organic It is thought that it also has an effect on insolubilizing halides. Examples of the silicate include sodium silicate, calcium silicate, magnesium silicate, sodium calcium silicate, etc., and use of magnesium calcium silicate is preferred. Moreover, silicic acid includes ortho-silicic acid and meta-silicic acid. Naturally occurring silicates can be advantageously used as such silicates. In the reaction system of the present invention, such silicates react with organic halides to produce organohalopolysiloxanes, or react with various metal elements present in the reaction system to form water-insoluble compounds, such as , Gehlenite, etc. are thought to be formed. As the inorganic filler, various inorganic compounds and clay minerals are used, such as calcium carbonate, gypsum, silica, zeolite, perlite, sepiolite, white clay, neutral china clay, kaolin, bentonite, loess, and the like. Such fillers are
In addition to showing the effect of diluting the exothermic reaction, it also shows the effect of making the product of the present invention into a powder solid form that is easy to handle. Next, the proportions of each of the components used in the present invention are as follows: calcium oxide and/or magnesium oxide: 40 to 70% by weight, water-soluble polymer: 1.5 to 10% by weight, organic acid metal salt: 2 to 10% by weight. %,
5-15% by weight of silicate and 15-30% by weight of filler. To carry out the method of the present invention, each component is added to a mixer and stirred uniformly, and then water is added and stirred. This operation causes an exothermic reaction and the temperature rises, but the organic halide to be treated is added at about 120 to 150°C and stirring is continued. When this stirring is usually performed for about 1 to 5 minutes, a powdery treated product is obtained. In the case of the present invention, various modifications are possible. For example, water can be added first before mixing each additional component, and the order of mixing each component can be arbitrary, and the water-soluble polymer can be mixed with methanol. Dissolve it in advance in an organic solvent such as and add it to water.
This can be added to a mixture of other additive components and organic halides to carry out the reaction. Furthermore, in the case of the present invention, each additive component can be prepared in advance as a homogeneous mixture, and this mixture, water, and organic halide can be mixed and reacted on-site. An example of such a mixture is shown in the table below.

【table】

[Table] The reaction in the present invention is carried out at a temperature below the boiling point of the organic halide, and in the case of PCB, it is preferably carried out at about 90 to 145°C. The reaction temperature can be adjusted by adjusting the amount of inorganic extender added. As the reactor, a sealed type is used. The ratio of each of the above additive components to the organic halide varies depending on the type of organic halide and reaction conditions, but generally the total amount of the additive components is 25 parts by weight per 100 parts by weight of the organic halide.
~200 parts by weight. In addition, the water usage rate is
It is about 5 to 100 per calcium oxide and/or magnesium oxide. The treated product obtained by the present invention is a fixed organic halide, and there is almost no elution of the organic halide from the solid material, and the product is a product of the Environmental Agency Notification No. 13 of 1970 (I). ) in the dissolution test,
No organic halides were detected. The processed product obtained in the present invention is in powder form, and this product is
If necessary, it can be formed into any shape such as pellets or lumps. The present invention will be explained below by giving Examples and Comparative Examples of the present invention. Example 1 A treatment agent containing the ingredients described in the table below was used to treat transformer oil containing PCBs.

[Table] The composition of the PCB-containing transformer oil was as described in Table.

[Table] The temperature of the transformer oil used was 21℃. The temperature of the treatment agent was 22°C, and the temperature of the water used for reaction with the treatment agent was 21°C. 200 grams of the processing agent shown in the table was placed in a small mixer, and 40 c.c. of water was added and stirred to cause an exothermic reaction. After reaching 142℃ in about 20 seconds, the PCB
Added 100 grams of trans oil and continued stirring. When I measured the temperature after about 2 minutes, it was 96℃.
It was hot. After measuring the temperature, the mixture was stirred for another minute and the powdered mixture was taken out. This temperature was 82°C. After air-drying this powder and bringing it to room temperature, the PCB
A dissolution test was conducted. The test method was in accordance with the Environment Agency Notification No. 13 (a) of 1971. The test results did not detect any PCBs, indicating that the PCBs were immobilized in the treatment agent. Example 2 200 grams of a processing agent having the ingredients described in the table below were put into a small mixer, and while stirring, 100 grams of transformer oil containing PCB described in the table was added. When the temperature rose to 82°C, 3.5 grams of carboxymethyl cellulose was dissolved in 5 cubic centimeters of methanol, and then water was added.
Add 100 grams, add the diluted solution and add 2 more
Stir for a minute. The exothermic reaction further increased the temperature to 126°C. The powdered material was taken out and subjected to the same elution test as in Example 1, but no PCB was detected, indicating that the treatment was complete.

[Table] Comparative Example 1 A treatment agent with the component composition described in the table below is
It was used to process transformer oil containing PCBs.

[Table] PCB-containing rinse oil was as described in Table. The temperature of the transformer oil used was 21°C. The temperature of the treatment agent was 22°C, and the temperature of the water used for reaction with the treatment agent was 21°C. 200 grams of the processing agent shown in the table was placed in a small mixer, 40 c.c. of water was added, and the mixture was stirred to cause an exothermic reaction. After reaching 145°C in about 20 seconds, 100 grams of transformer oil containing PCB was added and stirring was continued.
The temperature was measured after about 2 minutes and was 91°C. After measuring the temperature, the mixture was further stirred for 1 minute, and the powder was taken out. This temperature was 76°C. This powder was subjected to the same dissolution test as in Example 1. The test result was 0.0035 mg/, indicating that this method is unsuitable due to the absence of polymer. Example 3 An experiment was conducted in the same manner as in Example 1 except that sodium polyacrylate was used instead of carboxymethyl cellulose. Also in this case,
We were able to obtain a powder with no elution of PCBs. As is clear from the examples, the present invention has succeeded in immobilizing organic chlorine compounds such as PCBs, which was previously considered almost impossible. It facilitates the immobilization of hydrogen halide substances that are sometimes generated, and also enables the immobilized organic halides to be thermally decomposed at a low temperature of 800°C to 1000°C. By thermally decomposing the powder produced by the process of the present invention in a decomposition furnace, it is possible to decompose and detoxify organic halogen compounds such as PCBs, and if a trace amount of undecomposed organic halides remains. It is completely fixed in the ceramic treatment agent and will not be eluted due to weathering even if it is left in a bad environment for a long time. Considering the current situation where many PCBs are stored untreated and distributed throughout Japan, and are exposed to the risk of contamination and pollution due to natural disasters, container damage, etc., this invention is an extremely useful technology. can.

Claims (1)

[Scope of Claims] 1. When causing an exothermic reaction between calcium oxide and/or magnesium oxide and water, the reaction is carried out together with a liquid organic halide, a water-soluble polymer containing a hydroxyl group and/or a carboxyl group, an organic acid metal salt, 1. A method for immobilizing a liquid organic halide, which process is carried out in the presence of a silicate and an inorganic filler to finally obtain a solid solid on which the liquid organic halide is immobilized. 2. A liquid organic halide immobilization treatment agent comprising a mixture of calcium oxide and/or magnesium oxide, a water-soluble polymer containing a hydroxyl group and/or a carboxyl group, an organic acid metal salt, a silicate, and an extender.