A method of the decontamination of dangerous substances from wood and / or wooden materials

Abstract

A method of the decontamination of dangerous substances from wood and / or wooden materials, characterized by the fact that the contaminated wood and / or wooden material is shredded to a maximum size of 1,000 cm3. It is then rinsed with a solution of water containing potassium or sodium soap, and / or a surfactant, and / or sodium hydroxide, and / or potassium hydroxide, and / or calcium hydroxide in a concentration of 0.1 to 15% by weight and at a minimum temperature of 15°C. The cellulose and lignin contained in the wood or wooden material absorb the mixture of water with potassium or sodium soap, and / or a surfactant, and / or sodium hydroxide, and / or potassium hydroxide, and / or calcium hydroxide, leading to the softening of cellulose and lignin fibers. At the same time, this process releases toxic organic substances or volatile inorganic substances, particularly from the group of polychlorinated biphenyls, polycyclic aromatic hydrocarbons, arenes, and aliphatic compounds.

Description

[0001] Title: A method of the decontamination of dangerous substances from wood and / or wooden materials

[0002] Technical Field

[0003] The technical solution of the invention pertains to a method for removing toxic organic substances or voiatile inorganic substances, particularly from the group of polychlorinated biphenyls, polycyclic aromatic hydrocarbons, arenes, and aliphatic compounds, from wood and / or wooden materials.

[0004] State of the Art

[0005] Several methods for removing dangerous substances from solid materials are known in the prior art. One method involves burning waste material at high temperatures; however, this method is highly energy-intensive and releases harmful substances into the atmosphere during combustion. When burning waste containing organochiorine carbons, highly toxic substances, such as dioxins, can form.

[0006] A disadvantage of this technical solution is that contaminated carriers of dangerous substances, such as wood, are also destroyed if they are organic in origin.

[0007] For inorganic substances, the residue after incineration is generally thermally transformed to such an extent that it cannot be reused. Another method involves heating the contaminated material to a temperature at which the contaminants evaporate; the vapors are then directed to a condenser where they are liquefied. This method is described, for example, in technical solutions US 5,230,167, US 5,514,286, PV 1996-3781 , UV 1996-5721 , PV 2003-2717, and PV 2004-609.

[0008] The disadvantage of these methods is the decontamination at temperatures where, due to the presence of oxygen or air, materials oxidize, or bound oxygen is released into the atmosphere of the decontamination apparatus. When decontaminating organic solid substances, particularly wood, the material often becomes carbonized or ignites.

[0009] Another disadvantage is the need for gradual cooling of the decontaminated material to prevent ignition in the case of organic materials, as well as the requirement to remove all gaseous components from the decontamination apparatus to prevent condensation of gases back onto the decontaminated material during cooling. Essence of the invention

[0010] The aforementioned disadvantages are eliminated by a method for decontaminating dangerous substances from wood and / or wooden materiais according to this invention. The method involves shredding the contaminated wood and / or wooden material to a maximum size of 1,000 cm3, followed by rinsing with a solution of water containing potassium or sodium soap, and / or a surfactant, and / or sodium hydroxide, and / or potassium hydroxide, and / or calcium hydroxide at a minimum concentration of 0.5% by weight and a temperature of at least 15°C.

[0011] The cellulose and lignin in the wood or wooden material absorb the water mixture, leading to the softening of cellulose and lignin fibers. Simultaneously, toxic organic substances or volatile inorganic substances, particularly from the group of polychlorinated biphenyls, polycyclic aromatic hydrocarbons, arenes, and aliphatic compounds, are released.

[0012] It is advantageous to further rinse the wood and / or wooden materials with water vapor at a temperature of at least 100°C, washing dangerous substances out of the opened structure of the contaminated wood or wooden material.

[0013] Dangerous substances are then removed along with the water vapor or its condensate for further purification.

[0014] Contaminants can be removed using filtration, ultrafiltration, reverse osmosis, or demulsification.

[0015] Furthermore, saturated and / or superheated steam can be used for decontamination.

[0016] This method of the decontamination of dangerous substances from wood and / or wooden materiais preserves the material's mass and structure while achieving low energy consumption throughout the process.

[0017] Examples of Implementing the Invention

[0018] Example 1

[0019] A method for decontaminating dangerous substances from wood and / or wooden materials according to the presented invention consists in that the contaminated wood and / or wooden materia! is crushed to a maximum size of 1,000 cm3. The contaminated materia! prepared in this way is piaced in a vertically oriented container, preferably a cylindrical container equipped with an upper openable lid and inlets for liquid and water vapor, arid a lower openable lid with closable openings for the outlet of liquid and water vapor.

[0020] The contaminated material is rinsed with a solution of water with potassium soap, where the concentration of the soap in the water is 0.5% by weight. The temperature of the aqueous mixture is preferably 22°C.

[0021] Rinsing with the soap solution takes place for 2 to 50 minutes.

[0022] During the rinsing of the contaminated material, the mixture of water with potassium soap is absorbed by the cellulose and lignin contained in the wood or wooden material, thereby softening the fibers of cellulose and lignin. At the same time, toxic organic substances or volatile inorganic substances, particularly from the group of polychlorinated biphenyls, polycyclic aromatic hydrocarbons, arenes, and aliphatic compounds, are released.

[0023] The wood or wooden material prepared in this way is then rinsed with water vapor at a temperature of 110°C, wherein the contaminated wood and / or wooden material is exposed to water vapor, which washes dangerous substances out of the thus-opened structure, and these substances are, along with the water vapor or its condensate, carried away for further purification.

[0024] For example, it is possible to use a mixture of water with sodium soap at a concentration of at least 0.5% by weight, preferably a concentration of 2% by weight.

[0025] Example 2

[0026] A method for decontaminating dangerous substances from wood and / or wooden materials according to the presented invention consists in that the contaminated wood and / or wooden material is crushed to a maximum size of 1,000 cm3. The contaminated material prepared in this way is placed in a horizontal rotating container with openable lids equipped with openings far the inlet and outlet of liquid.

[0027] The contaminated material is rinsed with a solution of water with an anionic surfactant based on alkylbenzene sulfonate, where the concentration of the surfactant in the water is 3% by weight, and sodium hydroxide, where the concentration of sodium hydroxide is 1% by weight. The temperature of the aqueous mixture is preferably 35°C.

[0028] Rinsing of the contaminated material in the aqueous solution of the surfactant and sodium hydroxide takes place for 2 to 50 minutes, preferably 30 minutes.

[0029] During the rinsing of the contaminated material, the mixture of water with the surfactant is absorbed by the cellulose and lignin contained in the wood or wooden material, thereby softening the fibers of cellulose and lignin. At the same time, toxic organic substances or volatile inorganic substances, particularly from the group of polychlorinated biphenyls, polycyclic aromatic hydrocarbons, arenes, and aliphatic compounds, are released.

[0030] After the washing process is completed, the contaminated material is transferred to a cylindrical vertically oriented container equipped with an upper openable lid and an inlet for water vapor, as well as a lower openable lid with closable openings for the outlet of liquid and condensate. The wood or wooden material is then rinsed with water vapor at a temperature of 150°C, wherein the contaminated wood and / or wooden material is exposed to water vapor, which washes dangerous substances out of the thus-opened structure, and these substances are, along with the water vapor or its condensate, carried away for further purification.

[0031] For example, it is possible to use a mixture of water with sodium soap at a concentration of at least 0.25% by weight, preferably a concentration of 2% by weight.

[0032] For example, it is possible to use a mixture of water with sodium hydroxide at a concentration of 2% by weight, or potassium hydroxide at a concentration of 4% by weight, or calcium hydroxide at a concentration of 3% by weight. Industrial Applicability

[0033] A method of the decontamination of dangerous substances from wood and / or wooden materials according to this invention can be effectively, economically, and ecologically applied across ail industrial sectors where recycling of industrial materials is required for disposal and / or further use.

Claims

CLAIMS1. A method for decontaminating dangerous substances from wood and / or wooden materials, characterized in that the contaminated wood and / or wooden material is crushed to a maximum size of 1 ,000 cm3, which is then rinsed with a solution of water with potassium or sodium soap, and / or a surfactant, and / or sodium hydroxide, and / or potassium hydroxide, and / or calcium hydroxide in a concentration of 0.1 to 15% by weight and at a temperature of at least 15°C, wherein the cellulose and lignin contained in the wood or wooden material absorb the mixture of water with potassium or sodium soap, and / or a surfactant, and / or sodium hydroxide, and / or potassium hydroxide, and / or calcium hydroxide, and the fibers of cellulose and lignin are softened while toxic organic substances or volatile inorganic substances, particularly from the group of polychlorinated biphenyls, polycyclic aromatic hydrocarbons, arenes, and aliphatic compounds, are released.

2. A method for decontaminating dangerous substances from wood and / or wooden materials according to claim 1 , characterized in that the contaminated wood and / or wooden material is rinsed with water vapor at a temperature of at least 100*C, wherein the contaminated wood and / or wooden material is exposed to water vapor, which washes dangerous substances out of the thus-opened structure, and these substances are, along with the water vapor or its condensate, carried away for further purification.

3. A method for decontaminating dangerous substances from solid materials according to claim 2, characterized in that the contaminants are removed by filtration, and / or ultrafiltration, and / or reverse osmosis, and / or demulsification.

4. A method for decontaminating dangerous substances from solid materials according to claim 2, characterized in that saturated and / or superheated water vapor is used for the decontamination.