JP3316175B2 - Organochlorine compound decomposing agent, its production method and use - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an organochlorine compound decomposing agent, a method for producing the same and a use thereof, and particularly to trichloroethylene and tetrachloroethylene as the organochlorine compound.

[0002]

SUMMARY OF THE INVENTION Trichlorethylene and tetrachloroethylene are low-boiling chlorine solvents and are excellent in degreasing properties, and are generally called "triclo" and "perchlo", respectively, for washing and cleaning machines. It is used in dry cleaning factories, plating factories, semiconductor factories, etc., but has been found to cause liver damage and central nervous system damage when accumulated in the body, and to show carcinogenicity even in extremely small amounts. Designated as a designated chemical substance by the Chemical Substances Control Law in 2012, and is also subject to the current water quality and environmental standards (24 items) by the Environment Agency,
Substances with reference values of 0.03 mg / l or less and 0.01 mg / l or less.

[0003] Even if the notification of production is obliged by the Chemical Substances Control Law and designated as a water quality inspection item for groundwater such as well water, the contamination of soil and groundwater by the above-mentioned organochlorine compounds will become an environmental issue in December 1986. even Oite the findings published by the Office has over 23 prefectures, since then also these organic chlorine compounds continue to be used, but contaminated areas are presumed to have further spread,
There is no fundamental countermeasure for this. In other words, the current measures against pollution are carried out under the guidance of local governments, but the content is mostly embedment in concrete tanks and sealing treatment such as impermeable construction using impermeable sheets. The gas suction method and the like have also been proposed, but the former is symptomatic, and the risk of leakage is inevitable afterwards, and the latter has problems in the subsequent treatment, and therefore both are drastic. It is not a measure.

[0004] Accordingly, an object of the present invention is to provide a decomposer for these organochlorine compounds, a process for producing and decomposing the same, thereby purifying contaminated soil and groundwater, and consequently, in the aforementioned various factories. The purpose of the present invention is to provide a measure for treating the wastewater to positively prevent the pollution itself.

The organochlorine compound decomposer according to the present invention comprises 85-95 parts by weight of metal silicon particles and silver zeolite particles.
5-15 parts by weight, titanium powder 5-15 parts by weight, anhydrous sodium silicate 3-8 parts by weight, tourmaline powder 2-
5 parts by weight and 10% by weight of the total weight of the formulation
The resulting porous body can be manufactured by adding and mixing parts of water and subjecting the obtained porous body to a smoke-burning treatment.

In the method for producing an organochlorine compound decomposing agent according to the present invention, metal silicon particles, silver zeolite particles, titanium powder, anhydrous sodium silicate, and tourmaline powder are blended, and water is added. As a result, a porous formed body can be obtained by putting the above mixture into an appropriate mold. This porous molded body is smoked and baked, using a kiln for bamboo charcoal and reducing the temperature inside the kiln.
Keep at 750-900 ° C for 3 days, then 150
It is carried out by lowering the temperature to -250 ° C and then maintaining the temperature for 3 days. By this treatment, at least a part of the metallic silicon becomes silicon carbide, and the porous body is impregnated with soot or activated carbon. The obtained porous fired body can be used as it is as an organic chlorine compound decomposing agent, or can be crushed or pulverized.

When the organochlorine compound decomposing agent obtained as described above is brought into contact with an organochlorine compound, the organochlorine compound is gradually decomposed. The decomposition of trichlorethylene and tetrachloroethylene is, for example, once converted into an intermediate such as cis-1,2-dichloroethylene by the action of microorganisms in soil, and then gradually decomposed into carbon dioxide and water. However, when the decomposing agent according to the present invention is used, the mechanism of action is unknown, but the formation of the above-mentioned intermediate is not recognized, and it is presumed that it is directly decomposed. Therefore, the present invention can be said to be extremely excellent also in that an organochlorine compound intermediate which may be harmful to the human body is not formed and secondary pollution is not caused.

[0008]

Next, the present invention will be described more specifically and in detail with reference to production examples of the organochlorine compound decomposing agent according to the present invention and test examples using the decomposing agent. Production Example 90 parts by weight of metal silicon particles ( manufactured by Osaka Special Alloy Co., Ltd.), 10 parts by weight of silver zeolite particles [“Sidaps Z” (trademark) manufactured by Nippon Chemical Industry Co., Ltd.], and titanium powder
10 parts by weight (manufactured by Toho Titanium Co., Ltd.), 5 parts by weight of anhydrous sodium silicate (obtained from Nacalai Tesque Co., Ltd.), and 3 parts by weight of tourmaline powder (obtained from Adan Mining Central Research Institute Co., Ltd.) Parts by weight were added and mixed, and the mixture was dispensed into a mold and allowed to stand.

The solidified porous granules were removed from the mold, placed in a kiln for bamboo (Moso bamboo) charcoal, and smoked. This treatment was carried out by maintaining the temperature in the kiln at 850 ° C. for 3 days, then gradually decreasing the temperature to 200 ° C. over 1 day, and maintaining this temperature for 3 days.

Thereafter, the product was taken out of the kiln and allowed to cool to obtain a desired organic chlorine compound decomposing agent. This decomposing agent is a black porous granular material, and the impregnation amount of soot or activated carbon is about
23%.

Test Example 1 A standard solution (1 mg / l) of trichloroethylene (hereinafter abbreviated as “triclo”) and tetrachloroethylene (hereinafter abbreviated as “perchlo”) was prepared using tap water. Meanwhile, 2
Prepare a 00 ml furan bottle, inject 200 ml of the above standard solution into one of the bottles, and in the other bottle, add 2, 10 or the organochlorine compound decomposer obtained by the above production example.
20 g were charged, and then the insides of these bottles were filled with the above standard solution. Each franc bottle was fixed on a horizontal shaking table, shaken at a temperature of 20 ° C and a shaking condition of 70 times / min for 24 hours, and then the concentration of triclo and perclo was determined using a head space type gas chromatograph analyzer. Was measured. The results were as shown in Table 1 below.

[0012]

[Table 1]

Although the concentration of the organochlorine compound was set to a low concentration of 1.0 mg / l from the viewpoint of air diffusion control, as apparent from Table 1 above, about 0.6 mg / l was obtained immediately before the start of the test. l had to drop. Although the reason for this is not clear, it is considered to be related to the fact that the liquid temperature was high, and the furan bottle used for the test was not immersed in water and cooled beforehand. In any case, as it is clear from Table 1 above, as set larger amount of degradation agent can reduce the trichloro and Pakuro concentration seen Rukoto.

Test Example 2 Part 1: About 20 g of each of the organochlorine compound decomposers obtained in the above-mentioned production examples and about 10 times the weight of tap water were added to one beaker and the liquid temperature was measured. PH and oxidation-reduction potential (ORP) were measured (the measuring instruments were HM-12P pH meter and IM-40S type ORP meter manufactured by Toa Denpa Kogyo Co., Ltd.). Then, add hydrochloric acid to one beaker and adjust the pH of the solution.
To about 7, then add temperature, pH and ORP over time.
Was measured. In addition, only 200 ml of tap water and 200 ml of tap water
The same measurement was performed for both control samples prepared by adding the same amount of hydrochloric acid as previously added. The results were as shown in Table 2 below.

[0015]

[Table 2] Sample A: Decomposer 19.6 g + tap water 196 ml, Sample B: Decomposer 19.9 g + tap water 199 ml + hydrochloric acid 1.25 ml, Sample C: tap water 200 ml, Sample D: tap water 200 ml + hydrochloric acid 1.25 ml

Part 2: The same preparation operation as in the above test example (part 1) is performed, except that in this test example, p
Adjust with hydrochloric acid so that H becomes 7.0.
The liquid temperature and ORP were measured. On the other hand, as a control sample, only tap water was used without adding a decomposing agent, and pH, liquid temperature and ORP were measured by adding hydrochloric acid over time. The results were as shown in Table 3 below.

[0017]

[Table 3] Sample E: Decomposing agent 19.5g + tap water 195ml, Sample F: tap water 195ml

In the above tests (Nos. 1 and 2), tourmaline (a trace component) contained in the organochlorine compound decomposing agent according to the present invention is called "tourmaline", and although it is weak, water is removed. It has been suggested that the substance has the property of electrolyzing and also decomposing organic matter in water at that time.Therefore, the decomposition of triclo and perclo in Test Example 1 may have the possibility of such an action mechanism. It is an experiment performed to presume that there is, but the above table
As is clear from FIG. 3, the decomposing agent according to the production example has the effect of raising the pH of tap water and lowering ORP. O
The decrease in RP means that the decomposing agent electrolyzes water to cause a reduction reaction, and is converted into reduced water. On the other hand, in the control sample F, a relatively remarkable increase in the ORP value was observed, which means that the oxidizing substance was increased.

Test Example 3 Into two Erlenmeyer flasks, about 30 g each of the organochlorine compound decomposing agent obtained in the above-mentioned production example and about 10 times the weight of tap water were injected, and the pH was measured. The pH was adjusted to about 7 by adding hydrochloric acid to one flask. The above flask is sealed with a silicon rubber stopper fitted with a glass rod and a silicone rubber tube, and a hydrogen gas detector tube (manufactured by Gastec Co., Ltd.) is attached to the free end of the silicone rubber tube.
After stirring the liquid with a glass rod so that the liquid does not pour on the stopper, leave the mixture, and after 6 hours and 3 days, observe the change in color in the detector tube to qualitatively determine the presence or absence of hydrogen gas generation. Examined. A control test using only 300 ml of tap water was also performed. The results were as shown in Table 4 below.

[0020]

[Table 4] Sample G: tap water 300 ml, sample H: tap water 297 ml + decomposer 29.7 g (pH 9.2), sample I: tap water 296 ml + decomposer 29.6 g + hydrochloric acid 0.015 ml (pH 7.2)

The results in Table 4 above, which show the evolution of hydrogen gas, demonstrate that the decomposing agent according to the invention caused electrolysis in water, confirming the results from Test Example 2 above. .

Test Example 4 Referring to the results shown in Test Examples 1-3 above, it is suggested that the decomposition of triclo and perchlor is at least related to electrolysis. If this were the case, the concentration of the electrolyte in the solution would be relevant. Therefore, an experiment using a mineral water system and an ultrapure water system was attempted. In other words, the same test as in Test Example 1 was performed by changing the environmental conditions, etc., that is, in a chemical storage always kept at 5 ° C, turning off the light except during work, and conducting the experiment in the dark room state and in the following manner. It was. In this experiment, first, a standard solution of triclo and perchlo having a higher concentration than in Test Example 1 (about 5 m
g / l). Prepare a 200 ml furan bottle, add 20 g of the organochlorine compound decomposer obtained in the above-mentioned preparation example for the test, and fill the bottle with the standard solution of a predetermined concentration.On the other hand, for the control, Each bottle was filled with the given standard solution. After that, these fran bottles were fixed on a horizontal shaking table, shaken under the vibration condition of 70 times / min, and the concentration of triclo and perclo was measured over time using a head space type gas chromatograph analyzer. For 10 days. The results were as shown in Table 5 below.

[0023]

[Table 5]

If the values relating to the concentration of triclo or perclo shown in Table 5 above are expressed as the time-dependent decomposition rate of triclo or perclo with the value of 100 at the time of shaking time 0, that is, immediately before the start of the test, the following can be obtained. Table 6 below.

[0025]

[Table 6]

The following can be seen from the results shown in Tables 5 and 6 above. (1) When the decomposing agent according to the present invention is used, the concentration of trichlor and perchlor decreases with time in both the mineral water system and the ultrapure water system.
-By the 5th day, the mineral water system is higher than the ultrapure water system, and the trichloride is higher than the perchlor. (2) The decrease in the decomposition rate of triclo and perchlor decreased linearly or almost linearly in mineral water systems.
It was until the day, but in the ultrapure water system, it was from the second day to the 10th day of the final day of the experiment, and the circumstances differ between the two systems. (3) On the 10th day of the experiment, the triclo and perchlor concentrations on day 10 were lower in the ultrapure water system than in the mineral water system. Although the cause is unknown, it clearly suggests that factors other than electrolysis are also involved in the decomposition of both organochlorine compounds, and tourmaline is present in trace components in the components constituting the decomposer according to the present invention. It is known that silver zeolite (which contains alumina as a main component and contains zinc oxide and a small amount of silver oxide II as an accessory component) has an antibacterial effect, but it does not decompose organic compounds. Although it is not reported that titanium is obtained by calcination, it is known that when it is irradiated with ultraviolet light, it exhibits a strong oxidizing power by photocatalysis and also oxidizes and decomposes trichlor and perchlor. The above experiment was conducted in a chemical warehouse where ultraviolet rays were blocked, assuming the actual decomposition of tricro and perchro in soil and groundwater channels. Considering that it was performed in a chamber and that sodium silicate only functions as a binder, silicon carbide formed by carbonizing metallic silicon, which is the main raw material, is used for decomposition of trichlor and perchlor. It is suggested that it greatly contributes. (4) Decomposition of triclo and perclo is, for example, in the soil, once converted to an intermediate such as cis-1,2-dichloroethylene by the action of microorganisms, and then gradually decomposed into carbon dioxide and water. However, according to this experiment, no intermediate was found on the gas chromatogram of the gas chromatograph, and thus the decomposing action of the decomposing agent according to the present invention was clearly different from the stepwise decomposition by microorganisms. (5) Although this experiment was performed with the room turned off, that is, in a dark room state, the decomposing agent according to the present invention exhibited trichlor and perchlor resolution, and thus the decomposing agent according to the present invention was based on these organochlorine compounds. It strongly suggests its potential for contaminated soil contamination and groundwater purification.

The results of an investigation of the resolution of the decomposition agent according to the present invention for triclo and perclo on the 0th to 5th days of this experiment were as shown in Table 7 below.

[Table 7]

[0028]

The decomposer according to the present invention exerts the ability to decompose organochlorine compounds without the aid of light such as ultraviolet rays and under relatively low temperature conditions. Since this decomposing agent is manufactured by calcining a mixture of metallic silicon, silver zeolite, titanium, anhydrous sodium silicate, and tourmaline, it does not cause pollution even if it is put into soil or into the flow path of groundwater. It decomposes harmful organochlorines, in particular trichloroethylene and tetrachloroethylene, without producing potentially harmful intermediates. Therefore, the minute of the invention provides an innovative approach. Removal of contaminated soil and groundwater by chlorinated organic compounds, also the present invention the drainage processing of various plants that have to produce chlorinated organic compounds containing effluent The use of a disintegrant has an excellent effect of preventing the occurrence of pollution and pollution itself.

────────────────────────────────────────────────── ─── Continued from the front page (56) References JP-A-8-103765 (JP, A) JP-A-10-113679 (JP, A) JP-A-11-104422 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) C02F 1/00 A62D 3/00

Claims (5)

(57) [Claims] (1) 85-95 parts by weight of metallic silicon particles;
5-15 parts by weight of silver zeolite particles and 5-15 parts of titanium powder
And parts by weight, of anhydrous sodium silicate 3 - and 8 parts by weight, tourmaline powder 2 - blended with 5 parts by weight, the total of the formulation
A process for producing an organochlorine compound decomposing agent, characterized in that 10% by weight of water by weight is added and mixed, and the obtained porous body is subjected to a smoke baking treatment. 2. A smoking process using a kiln for bamboo charcoal.
The method according to claim 1, wherein the kiln temperature is maintained at 750-900 ° C for 3 days, then lowered to 150-250 ° C over 1 day, and then maintained at the temperature for 3 days.
3. The method for producing an organochlorine compound decomposer according to item 1. 3. 85 to 95 parts by weight of metal silicon particles;
5-15 parts by weight of silver zeolite particles and 5-15 parts of titanium powder
And parts by weight, of anhydrous sodium silicate 3 - and 8 parts by weight, tourmaline powder 2 - blended with 5 parts by weight, the total of the formulation
An organochlorine compound decomposer characterized by being obtained by adding and mixing 10% by weight of water by weight and subjecting the obtained porous body to a smoke-burning treatment. 4. A metal silicon particle comprising 85-95 parts by weight;
5-15 parts by weight of silver zeolite particles and 5-15 parts of titanium powder
And parts by weight, of anhydrous sodium silicate 3 - and 8 parts by weight, tourmaline powder 2 - blended with 5 parts by weight, the total of the formulation
10% by weight of water is added and mixed, and the fired product obtained by subjecting the obtained porous body to a smoke-burning treatment is brought into contact with an organic chlorine compound. Decomposition method. 5. The method for decomposing an organic chlorine compound according to claim 4, wherein the organic chlorine compound is one or both of trichloroethylene and tetrachloroethylene.