TW436340B - Method for sanitizing soil - Google Patents

Abstract

Chlorine dioxide aqueous solution with a concentration of 300 to 1400 ppm is applied at a rate of 200 to 250 liters per acre to soil contaminated with hazardous organic solvents, like trichloroethylene and tetrachloroethylene. Also, a chlorine dioxide aqueous solution with a concentration of 200 to 1400 ppm is applied at a rate of 2 to 15 liters per square meter to soil contaminated with hazardous materials, like dioxins and polychlorinated biphenyls. The present invention can sanitize contaminated soil and groundwater in a simple way.

Description

43634〇Α7 Β7 Printed by the Central Standard of the Ministry of Economic Affairs and Consumer Cooperatives V. Description of the Invention (1) [Background of the Invention] The present invention relates to a kind of purifying harmful substances containing trichloroethylene and other organic solvents, dioxins, polychlorinated Methods for soils such as biphenyls. [Prior art] Other organic solvents such as trichloroethylene are used in large amounts in degreasers, detergents, etc., and due to insufficient management, soil pollution or groundwater pollution occurs. problem. In order to treat such contaminated soil, various other methods such as high-temperature heating method have been proposed, but no matter which one, the processing equipment is large-scale, and its processing requires huge costs. In addition, dioxins are substances that are not intentionally produced during the synthesis of chemical substances or the combustion process of incinerators. In addition, PCBs are widely used as transformers or heat exchange media because of their thermal safety, insulation, and fluidity. These substances also cause problems with soil pollution or groundwater pollution. Β Contaminated The soil is changed by adding new soil, but the removed soil will cause a second pollution. Furthermore, although a method for high-temperature treatment of contaminated soil has also been developed, it also requires large-scale factory equipment, and its operation also requires huge costs. [Objective of the Invention] The purpose of the present invention is to provide a method for purifying soil and the like, which does not require special equipment, and can use a simple method to treat harmful substances such as organic solvents and dioxins in the soil. Polychlorinated biphenyls ---.------- show-(Please read the notes on the back before filling in this I)

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Γ The size of this paper is applicable to the Chinese National Standard (CNS) A4 specification (2 丨 〇 > < 297 mm) 83 · 3 · 10,000 436340 Printed by the Central Ministry of Economic Affairs of the Central People ’s Republic of China on consumption cooperation Du A7 ___B7__ 5. Description of the invention ( 2) Harmful Substances and Other Matters "[Inventive Summary] The inventor of the present invention has conducted various researches on the effective use of chlorine dioxide aqueous solution, and has also created a number of harmful microorganisms in the soil, etc. As a result, it was also found that the chlorine dioxide aqueous solution is also effective for the treatment of harmful substances such as trichloroethylene and other organic solvent systems, and dioxins and polychlorinated biphenyls. Therefore, the present invention has been completed. The invention is a process in which a dimonized chlorine aqueous solution acts on a harmful substance such as trichloroethylene in an organic solvent. For the contents of the soil, an aqueous solution of chlorine dioxide with a concentration of about 300 to 1400 ppm can be dispersed in the soil at a rate of about 200 to 250 liters per acre for effective treatment. In the present invention, a chlorine dioxide aqueous solution is used to treat a dioxin-type or polychlorinated biphenyl-type harmful substance. In addition, for the substances present in the soil, an aqueous chlorine dioxide solution having a concentration of about 200 to 1400 PPm can be dispersed in the soil at a ratio of about 2 to 12 liters per square meter for effective treatment. [Embodiments of the invention] The organic solvent-based harmful substances that can be treated by the chlorine dioxide aqueous solution are: U-dichloroethylene, dichloromethane, cis-1,2-dichloroethylene, and 1,2-dichloroethyl Alkane, 1,1,1-trichloroethane, carbon tetrachloride, benzene, trichloroethylene, cis-1,3-dichloropropene, trans-1,3-dichloropropene, 1,1, 2-Trichloroethane, tetrachloroethylene and other harmful substances. However, from the perspective of the amount used, the Chinese standard is used for the paper size (CNS > Α4 size (210X297 mm) 83.1 10,000 ^^^ 1 HE II ·---IΓ ^ ^ 1 (Please read the notes on the back before filling in this page)

tT 436340 A7 B7 Du Yinzhuang, male laborer's consumer cooperation of the Central Standards Bureau of the Ministry of Economic Affairs 5. Description of the invention (3) The effects of trichloroethylene and tetrachloroethylene are particularly effective. The concentration of chlorine dioxide in the chlorine dioxide aqueous solution is an appropriate concentration based on the object to be treated containing an organic solvent-based harmful substance, but a concentration of about 300 to 1400 ppm is generally preferred. This chlorine dioxide aqueous solution can be used by dispersing the organic solvent-based harmful substances, and when it is contaminated by easily-handled materials such as clothing, it can be treated by soaking. When it is dispersed in the soil, the chlorine dioxide aqueous solution can usually permeate to a depth of about one meter underground to act on harmful substances. Furthermore, in the soil treated in this way, the reproduction of earthworms can be clearly seen, and insects such as dragonflies have also become flying on them. The dioxin family includes polychlorinated dibenzo-p-dioxins. PCDD for short) and Polychlorinated dibenzofurans for short. And according to the binding position of chlorine, there are 75 kinds of PCDD and 135 kinds of different compounds in PCDF. And the most toxic 2,3,7,8-tetrachlorobiphenyldioxin (2,3,7,8- TCDD) and 2,3,7,8-tetrachlorobiphenylfuran (2,3,7,8-TCDF). This chlorine dioxide aqueous solution is particularly effective. The concentration of chlorine dioxide in the aqueous solution of chlorine dioxide containing the dioxin-containing to-be-processed object is adjusted to a proper concentration depending on the to-be-processed object, but it is generally preferred to use a concentration of about 200 to 1400 ppm. It is preferably used at a level of about 500 to 1000 ppm, and particularly preferably used at a level of about 600 to 900 ppm. This chlorine dioxide aqueous solution, except for the soil containing the above dioxins, etc. --------------- (Please read the precautions on the back before filling this page)

Order

C The paper size is used in the 0 countries Kneading rate (CNS) A4 specification (2 〖0 × 297 mm) 83.3.10,000 436340 A7 B7 The central government of the Ministry of Economic Affairs, Industrial and Consumer Cooperatives Co., Ltd. Imprint 5, Invention Description (4), etc. In addition to use, things that are easy to handle, such as clothing, can also be soaked when they are contaminated. In the case of soil, the above-mentioned concentration of chlorine dioxide aqueous solution can be dispersed at a ratio of about 2 to 15 liters per square meter, preferably about 3 to 10 liters, particularly preferably about 3 ~ 8 liters. In the case of spreading in the soil, the chlorine dioxide aqueous solution permeates the ground in the same manner, and forms and acts with dioxins and the like. As a first action, such an aqueous solution of chlorine dioxide can quickly and effectively decompose dioxins and the like by oxidation reaction. Then, as a second action, it can increase the redox potential in the soil and oxidize harmful substances to form Those who are favorable to the environment, in order to form a good soil environment that can reproduce by aerobic microorganisms, insects, small animals and so on. And in such an environment, harmful substances can be decomposed by an oxidation reaction or a hydrolytic reaction of the microorganism or the like. In addition, when the chlorine dioxide aqueous solution is dispersed, the addition of aerobic bacteria and the like can further promote the decomposition of harmful substances. [Test 1] An average of 50 ppb of 1,1-dichloroethylene and dichloromethane 'cis-1,2-dichloroethylene, 1,2-dichloroethane, and 1,1,1-trichloroethyl Alkane, carbon tetrachloride, benzene 'trichloroethylene, cis-1,3-dichloropropene, trans-1,3-dichloropropene, 1,1,2-trichloroethane, tetrachloroethylene 0.1 ml of the mixed solution was put into a medicine bottle, and a chlorine dioxide aqueous solution of 0.1 1 at a concentration of 60,000 ppm was added, and then it was tightly closed, and then analyzed by gas chromatography. The content (ppb), measured thorium (ppb), and reduction rate (%) of the above components are shown in Table 1 below. < Please read the note on the back before filling this page)

L > -—frtv m ll · V Packing _ Order h This paper is again applicable to China _ furniture standard (CNS) A4 size (210X297 mm) 83.1 10,000 436340 A7 B7 V. Description of the invention (5) [Table 1] Substance Content (Ppb) Determination of plutonium (Ppb) Reduction rate (%) U-Dichloroethylene 54.8 2.9 95% Dichloromethane 57.7 13.7 76% Cis-1,2-chloroethene 56.5 13.6 76% 1,2- Dichloroethane 48.8 20.7 58% 1, U-trichloroethane 63.1 8.6 86% Carbon tetrachloride 62.0 9.8 84% Benzene 61.4 10.9 82% Trichloroene 66.2 11.1 83% Cis-1,3-dichloro Propylene 51.3 20.9 76% Trans-1,3-chloropropane 46.6 23.8 49% 1,1,2-trichloroethane 47.8 25.6 46% Tetrachloroethylene 65.4 11.3 83% --------- Meal-(Please read the notes on the back before filling this page)

From the above results, it can be seen that for 1,1,2-trichloroethane 'trans-1,3-dichloropropene and 1,2-dichloroethane, there can be about a half reduction rate, but for For other substances, a reduction rate of more than 76% can be seen, so it can be seen that it is effective for any of them. [Experiment 2] Prepare a 750 ppm aqueous solution of chlorine dioxide, and add 1 to 500 ppb of 2,3,7,8-tetrachlorobiphenyldioxine (sample 1) and 2,3,7,8 to the 40 ml solution. -Tetrachlorobiphenylfuran (Sample 2) ', and each was ultrasonically stirred for 10 minutes, and left to stand at room temperature (20 ° C) for 3, 10, and 30 days, respectively, and then the concentration of the dioxin was measured. The scale of this paper is applicable to China National Standard for Ladder (CNS) Α4 Washing (210X297 Gong > Central Ministry of Economics and Trade, Central Bank of China, Baigong Consumer Cooperative Co., Ltd. 83. 3.10,000 433340 A7 B7 V. Description of Invention (6) [Concentration Measurement method] From each of the above samples after a certain period of time, dioxins were separated by liquid-liquid extraction, and after the pretreatment, the extract was identified and quantified by gas chromatography analysis. [Measurement result] [Table 2] Sample 0 3rd, 10th, and 30th 1 2,3,7,8-tetrachlorobiphenyl dioxin 600 680 430 410 2 2,3,7,8-tetrachlorobiphenylfuran 450 510 160 160 (Unit: Pg; tWl) Please read and read the notes before printing the printed version of the Male Workers Consumer Cooperatives of the Central Bureau of the Ministry of Economic Affairs [Examination] In Samples 1, 2 and 2 after the 3rd day Both increased by about 13%. Although it is not known what the reason is, the amount after the tenth day has decreased sharply, and after the 30th day, sample 1 has been reduced to about 2/3 of the original number, sample 2 Greatly reduced to about 1/3. In this way, it can be inferred The ring-opening decomposition of dioxins and the detachment of chlorine groups are described, and it is known that it is helpful to decompose and reduce them. [Examples of the invention] (Example 1) An aqueous solution of chlorine dioxide with a concentration of 60,000 ppm 40 liters' is diluted with about 2000 liters of water to make an aqueous solution of chlorine dioxide at a concentration of 1200 ppm. The diluted solution is spread on the soil contaminated with trichloroethylene at a rate of 200 to 250 liters per acre. For three weeks, it was left until the chlorine dioxide almost disappeared. After that, the trichloroethene in the soil was analyzed.

This paper is applicable to the standard of the middle and poor countries (CNS) A4 specification (210 × 297 mm) 83. 3.10,000 43634. Printed by the Central Ministry of Economy and Trade Standards and Consumers Cooperatives A7 _B7__ 5. Description of the invention (7) Can be measured to disappear 90%. It is conceivable that this is due to the strong oxidation of chlorine dioxide, which decomposes chlorine trioxide. (Example 2) 40 liters of an aqueous chlorine dioxide solution having a concentration of 60,000 ppm was diluted with approximately 3200 liters of water to prepare an aqueous solution of chlorine dioxide having a concentration of 750 ppm. 'The diluted solution was coated with 2,3,7,8- The soil contaminated with tetrachlorobiphenyl dioxine was spread at a rate of 1 square meter and 3 liters. It was placed about 30 days after the spread, and it was left until chlorine dioxide almost disappeared. After analyzing the amount of 2,3,7, S-tetrachlorobiphenyldioxine in the soil, it can be measured that about 80% disappeared. It is conceivable that this is due to the strong oxidation of chlorine dioxide, which oxidized and decomposed 2,3,7,8-tetrachlorobiphenyl dioxine. In addition, with the rise of the oxidation-reduction potential in the soil, aerobic microorganisms, insects, small animals, etc. multiply, and harmful substances are decomposed due to the oxidation reaction or hydrolytic reaction of these microorganisms. (Example 3) The same diluted solution of the chlorine dioxide aqueous solution as in the above Example 2 was spread on the soil contaminated with polychlorinated biphenyls used as the insulating oil for utility pole transformers at a rate of 1 square meter 3 liters. Of it. Approximately 30 days after spreading, it was allowed to stand until chlorine dioxide almost disappeared. After analyzing the amount of PCBs in the soil, it was found that about 90% disappeared. It is conceivable that this is because the same effect as in Example 2 was used to oxidize harmful substances. [Effects of the invention] The present invention is as described above, and can be harmful to organic solvents such as trichloroethylene (please read the note on the back before filling this page)

The scale of the paper is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm > 83.3.10,000 436340 A7 _B7 _ V. Description of the invention (8) The harmful substances, dioxins and / or polychlorinated biphenyls, etc. Substance, effective action and treatment, so simple and low-cost purification of contaminated soil and groundwater purification. ^^^ 1 i-f ^ (Please read the precautions on the back first (Fill in this page again)

ΪΤ k ♦ Printing policy of Shellfish Consumer Cooperatives, Central Bureau of Standards, Ministry of Economic Affairs This paper size applies to China National Standards (CNS) A4 Washing (210X297 mm) 83. 3.10,000

Claims (1)

436340 a8 Β8 C8 m 6. Scope of patent application 1. A method of purifying soil, etc. It is characterized by treating harmful organic substances such as vinyl chloride and other organic solvents in the soil with chlorine dioxide in water. 2. A method for purifying soil and the like, which is to disperse an aqueous chlorine dioxide solution with a concentration of 300 to 1400 PPm in the soil at a rate of 200 to 250 liters per acre, and treat other organic substances such as trichloroethylene existing in the soil. Solvent-based hazardous substances are characteristic. 3. A method for purifying soil and the like, which is characterized by treating dioxins and / or polychlorinated biphenyls present in the soil with an aqueous solution of chlorine dioxide. 4. A method for purifying soil and the like, which is to disperse an aqueous solution of chlorine dioxide having a concentration of 200 to 1400 ppm in the soil at a rate of 2 to 15 liters per square meter to treat dioxins and / or existing in the soil. Polychlorinated biphenyls are characteristic. (Please read the precautions on the back before filling out this page) Printed by the Consumer Cooperatives of the Central Bureau of Standards of the Ministry of Economic Affairs This paper is in Chinese Standard (CNS) A4 (2 丨 0X297 mm)