KR-102961326-B1 - Method for decontaminating gaseous media contaminated with suspended pollutants

KR102961326B1KR 102961326 B1KR102961326 B1KR 102961326B1KR-102961326-B1

Abstract

The present invention relates to a method for decontaminating a volume of a gaseous medium contaminated with suspended contaminant species, wherein the volume of the gaseous medium is in contact with at least one surface of a solid substrate, and the method comprises the following successive steps: a) forming a mist by spraying a microdroplet of an inorganic gel into the volume of the gaseous medium, wherein the gel is a colloidal solution comprising an inorganic viscosity enhancer and a solvent; b) capturing the suspended contaminant species by the droplet of the inorganic gel; c) depositing the droplet of the inorganic gel containing the captured suspended contaminant species onto the surface of the solid substrate; d) maintaining the gel on the surface of the solid substrate for at least a time sufficient for the gel to dry and form a dry solid residue containing the captured suspended contaminant species; and e) recovering the dry solid residue containing the captured contaminant species.

Inventors

고사드, 알반
튀르크, 위베르 알렉상드르
벤디티, 피에르
그랑장, 아그네스

Assignees

꼼미사리아 아 레네르지 아토미끄 에뜨 옥스 에너지스 앨터네이티브즈

Dates

Publication Date: 20260508
Application Date: 20190710
Priority Date: 20180711

Claims (20)

A method for decontaminating a volume of a gaseous medium contaminated with suspended contaminant species, wherein the volume of the gaseous medium is in contact with at least one surface of a solid substrate, and the method comprises the following successive steps: a) a step of spraying microdroplets into the volume of the gaseous medium to form a mist of an inorganic gel consisting of a colloidal solution comprising an inorganic viscosifying agent and a solvent; b) a step of capturing and absorbing the above-mentioned floating pollutant species by the above-mentioned inorganic gel droplets; c) a step of depositing the inorganic gel droplet containing the captured suspended contaminant species deposits onto the surface of the solid substrate; d) maintaining the inorganic gel on the surface of the solid substrate for at least a time sufficient for the inorganic gel to dry and form a dry solid residue containing the captured suspended contaminant species; e) A step of recovering the dry solid residue containing the captured floating pollutant species. A method including
A method according to claim 1, wherein the gaseous medium is air.
A method according to claim 1, wherein the volume of the gaseous medium is a sealed volume defined by an inner wall (paroi) including a floor, ceiling and walls forming the surface, the mist of the microdroplets fills the entire sealed volume, and the microdroplets of the inorganic gel containing the captured suspended contaminant species deposits settle on at least one of the inner walls.
In claim 1, the method wherein the microdroplets have a diameter size of 10 to 1000 μm.
A method according to claim 1, wherein the suspended pollutant species is in the form of solid particles, liquid particles, or molecular species.
A method according to claim 1, wherein the contaminant species is selected from chemical contaminant species, biological contaminant species, nuclear contaminant species or radioactive contaminant species.
A method according to claim 1, wherein the contaminant species is radioactive, and/or chemically toxic, and/or toxic due to its form, shape, and/or size.
In claim 7, the toxic contaminant species due to its form, shape, and/or size is a contaminant species in the form of solid particles including solid microparticles and solid nanoparticles, fibers including microfibers and nanofibers, nanotubes, or nanocrystalline forms.
In paragraph 6, the contaminant species is selected from metals, metalloids or metalloids in ionic form, and toxic metals and metalloids in metals, metalloids or ionic form; compounds of said metals and metalloids; ceramics; wood; grains; flour; and glass.
In paragraph 9, the above-mentioned contaminant is asbestos, method.
In paragraph 1, the colloidal solution comprises the following components: - Surfactant; - Active decontamination agent; - A trapping agent (" getter" ) that captures toxic or explosive gaseous contaminants; - Contamination species extractor; - Contamination fixative; - Coloring agent A method comprising additionally one or more components selected from
In paragraph 1, the colloidal solution is: - At least one inorganic thickener in an amount of 1 mass% to 30 mass% with respect to the mass of the gel; and one or more component(s) selected from the following components in the following proportions: - At least one surfactant in an amount of 0.1 mass% to 2 mass% with respect to the mass of the gel; - At least one active decontaminating agent of 0.1 to 10 mol/gel L; - At least one capturer ("getter") in an amount of 0.1 mass% to 5 mass% with respect to the mass of the gel, which captures toxic or explosive gaseous contaminant species; - At least one contaminant species extractant in an amount of 0.1 mass% to 5 mass% with respect to the mass of the gel; - At least one contaminant species fixative in an amount of 0.1 mass% to 5 mass% with respect to the mass of the gel; - At least one coloring agent in an amount of 0.01 mass% to 10 mass% with respect to the mass of the gel; and - Remaining amount of solvent A method including
In paragraph 1, the colloidal solution is: - At least one inorganic thickener in an amount of 1 mass% to 30 mass% with respect to the mass of the gel; and - Remaining amount of solvent A method including
The method according to claim 1, wherein the inorganic thickener is selected from metal oxides, metalloid oxides, metal hydroxides, metalloid hydroxides, metal oxyhydroxides, metalloid oxyhydroxides, aluminosilicates, clays, and mixtures thereof.
In paragraph 14, the method wherein the inorganic thickener comprises one or more alumina(s).
In paragraph 15, the alumina(s) represent 5 mass% to 30 mass% of the total mass of the gel.
In paragraph 15, the alumina(s) are selected from exothermic aluminas.
In claim 11, the active decontamination agent is selected from bases; acids, hydrogen oxalates; oxidizing agents, chlorates, cerium IV salts; quaternary ammonium salts; reducing agents; and mixtures thereof.
In claim 11, the surfactant is selected from nonionic surfactants.
In claim 11, the capture agent (" getter" ) is selected from a solid with a very high specific surface area containing an active surface site; cage material particles; and mineral oxide particles capable of reacting with the contaminant species to be captured.

Description

Method for decontaminating gaseous media contaminated with suspended pollutants The present invention relates to a method for decontaminating a gaseous medium contaminated with suspended pollutant species. The above gaseous medium may be air, and therefore the method according to the present invention is referred to as an air pollution removal method. Suspended pollutant species or suspended pollutants may be in the form of solid particles, liquid particles, or otherwise molecular species. More specifically, the decontamination method according to the present invention enables the capture, trapping, drawdown, and fixation of such suspended contaminants on a solid surface, and optionally the decontamination of the surface. The applications of the method according to the present invention are numerous and diverse, and are related to many fields of industrial and household activities. The removal of contaminants, such as fine particles, nanoparticles, dust, or fibers—e.g., asbestos fibers—or toxic molecules suspended in the atmosphere, or more generally in gaseous media, is a problem that arises in numerous fields, such as the reconstruction of nuclear facilities, the decommissioning of workplaces, or the removal of asbestos from workplaces, as well as in the purification of air filled with fine particles from heating appliances, particularly firewood. This problem can also occur particularly after so-called NRBC (nuclear, radiological, biological, chemical) events or natural disasters, and/or in post-treatment scenarios at sites contaminated with toxic chemical molecules or harmful biological microorganisms present in an airborne state. The removal of such airborne contaminants involves very complex treatment operations and requires the implementation of specific protocols, such as the wearing of specific equipment (work clothes, respiratory protection, etc.) or the installation of isolation airlocks and specific ventilation devices. In addition, since restrictive clothing must be used, the worker's intervention period is shortened. Finally, to remove these airborne pollutants, work sites in operation must be closed for most of the period. The risks associated with the presence of airborne pollutants are essentially risks to the health of workers or the general public, but they are also safety and environmental risks. The removal of airborne pollutants has a significant impact on various projects where this issue occurs, in terms of cost, safety, security, deadlines, or efficiency. Methods for removing pollutants, such as (nano)particles, dust, or fibers, e.g. asbestos fibers, or otherwise airborne toxic molecules in the atmosphere or, more generally, in gaseous media, can be classified into various types depending on the technology used. The first type of method is the method by which air filtration is performed. Accordingly, document US-A1-2006/0248866[1] relates to an air decontamination device for moving filtered air into a sealed space. The device comprises an enclosure having an air filtration compartment having an inlet and an outlet; at least a first air decontamination filter disposed in the air filtration compartment between the inlet and the outlet; and a device for moving air (" air mover" ) communicating with the air filter compartment to move air through the air decontamination filter. According to paragraph [0013], the air decontamination device may include a first air decontamination filter selected from the group consisting of a HEPA filter, an activated carbon filter, a biological agent filter, a chemical agent filter, and a radioactive agent filter. This device is a conventional device that filters contaminated air using a fixed filter that operates without spraying liquid in a dry state. There is no mention or suggestion in this literature of spraying, in particular vacuum minerals, inorganic gels, or even smaller gels, in the specific form of fine droplets into this gaseous medium, such as air, to capture, drop, or fix contaminants found in the gaseous medium. This type of method in which filtration is performed can also be combined with a photocatalytic method by including a lamp that emits UV light. Accordingly, the document WO-A3-2004/011041[2] relates to an air pollution removal device according to claim 1, comprising: an enclosure having an air inlet, an air outlet, and a passage through which air flows from the inlet to the outlet; a fixed filter disposed in the enclosure along the passage, the filter comprising an upstream side for receiving air flowing along the passage and a downstream side for discharging from the filter to the passage; at least a first fixed UV lamp disposed to directly illuminate the upstream side of the filter; and an ozone generator located near the filter. This device is a conventional device for filtering contaminated air using a fixed filter that operates without spraying liquid in a dry state, and also uses a UV lamp and an ozone generator. There is no m