JP4423506B2 - Asbestos removal method - Google Patents

Description

  The present invention relates to a method for removing an asbestos layer applied to a ceiling, a wall or the like of a building or other structures. Further, the present invention relates to a method for removing asbestos including a method for reusing asbestos-containing water used in a method for removing asbestos and a method for disposing of generated asbestos-containing materials.

  Conventionally, sprayed asbestos has been used as a heat insulating, fireproof, and sound absorbing material for buildings and other structures. However, it has become clear that dust from the asbestos can cause lung cancer or mesothelioma. Use is subject to strict restrictions.

  However, sprayed asbestos that was constructed before being subject to regulations may deteriorate, causing dust to scatter and cause asbestos pollution. Treatment methods to solve this include “containment treatment” in which asbestos is solidified by impregnating the surface or inside of asbestos with a solidifying agent, “enclosure treatment” in which the surface of the asbestos layer is covered so as to cover it, and the asbestos layer There is a “removal method” in which asbestos is stripped off manually by using a scraper or the like, or by jetting compressed air or high-pressure jet water.

  Among the above methods, “containment treatment” requires that asbestos remain in the building, the maintenance of the solidifying agent over time and damage is necessary, and once the containment treatment is performed, the removal treatment becomes difficult. There is a problem of becoming.

  As a typical example of the removal method, a nonionic surfactant mainly composed of an octylphenol derivative is injected or sprayed onto a sprayed asbestos part to wet the asbestos part, and the asbestos layer is disassembled in a substantially original state. It is a method (refer patent document 1 below). In this method, the penetration state of the surfactant varies depending on whether the asbestos layer is flat or corrugated, and the thickness of the asbestos layer. It becomes difficult to dismantle in the original state.

  When wetting, applying or injecting a wetting agent such as an octylphenol derivative onto an asbestos part and scraping it off using a removal tool such as a scraper, the fine particles of asbestos scattered from the scraped surface of the sprayed asbestos fall onto the floor part. Since the asbestos removal work site is strictly isolated and reduced in pressure to prevent external leakage of floating asbestos, there is still a risk of leakage from the entrance and exit etc. It cannot be fully achieved.

  As a second example of the removal method, it has been proposed to use a styrene acrylic copolymer resin as an asbestos dust scattering inhibitor (see Patent Document 2 below). However, there is a problem that it is difficult to completely penetrate the styrene acrylic copolymer resin into the innermost layer of the sprayed asbestos layer.

  Furthermore, as a method for preventing the scattering of dust generated during the removal of asbestos and the like, there is a method of applying a chemical containing a water retention agent, a thickener, a penetrating agent, a foaming agent and a curing agent, and then peeling and removing the object to be treated. It has been proposed (see Patent Document 3 below). The feature of this method is that the asbestos-containing material is cured by a curing agent, so it is aimed at removing it as a lump without peeling apart with a tool such as keren, but minute asbestos is scattered at the crack of the large lump. Inevitable, there was a problem in curing hard.

  When removing asbestos manually using a scraper or keren or other tool, work with a dust-proof gas mask, protective glasses and complete dust-proof clothing to prevent inhalation of asbestos. It is difficult to continue working. With the manual method of the worker, it is difficult to completely remove asbestos, and there is a possibility that a problem may arise in ensuring the safety of the worker.

As one of the solutions, a construction method using a high-pressure water jet has been proposed (see Non-Patent Document 1 below). After blowing sprayed asbestos unit to asbestos dusting inhibitor, water pressure when the asbestos surface stiff 600~700kg / cm ^2, asbestos layer water jet water pressure when soft surface is 500~600kg / cm ² It is a method of spraying on the asbestos layer and scraping off the asbestos layer. Although there was a result in scraping off asbestos relatively completely, when the asbestos layer was pulverized and cut with high-pressure water as described above, asbestos fine particles were blown into the high-pressure water from the cut surface of asbestos with conventional scattering inhibitors. There is a problem that it cannot be prevented from being scattered around. The asbestos removal work site is isolated by a vinyl sheet and prevents leakage of asbestos scattered under reduced pressure, but strict management is indispensable to prevent leakage of asbestos blown away by high pressure water, and high pressure water jet removal work However, it is necessary to more reliably suppress or prevent asbestos scattering.

  In addition, asbestos removal methods using pressurized water, such as the water jet method described above, require a large amount of water, and draining asbestos-containing water is not permitted for pollution measures, so filter collected asbestos containing a large amount of water. The filtrate must be reused. In addition, when asbestos removal work is completed, for example, when collecting asbestos adhered and collected on the surface of the filter medium, the filter medium is washed by flowing a little water from the opposite side of the filter medium, etc. The question of what to do about a complete detoxification process for the treatment of trace asbestos-containing water remains.

In addition, the above-described pressurized water recycling system for water jets and the high cost for detoxifying water containing trace amounts of asbestos hinder the spread of methods using pressurized water such as water jets.
Japanese Patent Laid-Open No. 62-178659 JP 2004-305904 A Japanese Patent Laid-Open No. 10-323614 Japan Architectural Center / Construction Maintenance Center Technical Examination Certificate 9801 [BCJ-Certification Certificate-32 (2003, 5, 18)]

  The present invention further improves these problems, and even when removing asbestos manually using a jig such as a scraper or keren, or by removing the asbestos by injecting pressurized water such as a water jet. In such a case, an object of the present invention is to provide a method for removing asbestos that is less likely to cause asbestos scattering.

  Furthermore, it aims at providing the asbestos removal method which can peel asbestos from the said iron structure more completely with the said objective, even when asbestos is sprayed on the iron structure.

  Furthermore, it aims at providing the asbestos removal method which enables recycling of pressurized water when performing asbestos removal using pressurized water with the said objective.

  Furthermore, it is another object of the present invention to provide an asbestos removal method that takes into account a detoxification method that can be put into practical use in terms of the cost of water containing a small amount of asbestos when removing asbestos using pressurized water.

To achieve the above object (1) The first asbestos removal method of the present invention is a treatment comprising asbestos in a composition comprising a drug containing a thickener, a soft binder and a wet penetrant and water. It is characterized in that asbestos is peeled off after being applied to an object.

  (2) In the asbestos removal method of the present invention described in the above (1), the drug is preferably a drug further containing a metal chelating agent.

  (3) In the second asbestos removal method of the present invention, asbestos is injected by injecting pressurized water containing a drug containing a thickener, a soft binder and a wet penetrant from a nozzle onto a treatment object containing asbestos. It is characterized by peeling and removing.

  (4) In the asbestos removal method of the present invention described in (3) above, the drug is preferably a drug further containing a metal chelating agent.

  (5) In the third asbestos removal method of the present invention, after applying a composition comprising a drug containing a thickener, a soft binder and a wet penetrant and water to a treatment object containing asbestos. Further, asbestos is peeled and removed by spraying pressurized water containing a drug containing a thickener, a soft binder and a wet penetrant from a nozzle onto a processing object containing the asbestos.

  (6) In the asbestos removal method of the present invention described in the above item (5), it is preferable that the drug constituting the composition is a drug further containing a metal chelating agent.

  (7) In the asbestos removal method of the present invention according to any one of (5) and (6) above, the drug in pressurized water containing the drug is preferably a drug further containing a metal chelating agent.

  (8) The fourth asbestos removal method of the present invention comprises (A) a thickener, a soft binder and a wet penetrant, or (B) a thickener, a soft binder, and wet penetrant. Pressured water containing an agent and an agent containing a metal chelating agent is sprayed from a nozzle onto a processing object containing asbestos to remove and remove asbestos, and the collected asbestos that has fallen and fallen as described in (A) or (B) above. In order to separate the water containing the drug, after filtering through a filter composed of a stainless mesh with a mesh opening of 1 to 100 μm, the filtrate is further refined by a polymer separation membrane having a pore size of 0.01 to 10 μm. It is characterized by filtering and recycling the filtrate as water for pressurization.

  (9) The fifth asbestos removal method of the present invention comprises (A) a thickener, a soft binder and a wet penetrant, or (B) a thickener, a soft binder, and wet penetrant. Pressured water containing an agent and an agent containing a metal chelating agent is sprayed from a nozzle onto a processing object containing asbestos to remove and remove asbestos, and the collected asbestos that has fallen and fallen as described in (A) or (B) above. In order to separate the water containing the drug, it is filtered through a filter composed of a stainless steel mesh with a mesh opening of 1 to 100 μm, and the filtrate is further filtered through a polymer separation membrane having a pore size of 0.01 to 10 μm. The asbestos residue filtered through the stainless steel mesh and the asbestos residue precisely filtered through the polymer separation membrane are collected as collected asbestos or processed as a specially controlled industrial waste, The microfiltered filtrate is circulated and used as pressurized water. Further, asbestos-containing wastewater is absorbed with a water-absorbing agent to form a solid, and then treated as specially controlled industrial waste.

(10) In the asbestos removal method according to any one of (2), (4), (6), and (7) to (9), the metal chelating agent is acrylic as a flexible binder. Acid / methacrylic acid methyl / ethyl ester copolymer concentration 5% by weight (solid content), di-2ethylhexyl sulfosuccinate sodium salt concentration 0.1% by weight as wet penetrant, starch glycolate sodium concentration as thickener Pressurized water (pressure 650 kg / cm ² ) containing 3% by weight and metal chelating agent concentration 3% by weight is injected onto asbestos-containing material at a distance of 20 cm from a nozzle with a diameter of 1 mm at a flow rate of 35 liters / min. After peeling and dropping, it is a compound in which almost no asbestos remains on the surface of the iron plate to which asbestos was adhered,
A metal chelating agent containing at least one selected from the group consisting of a hydroxylaminocarboxylic acid derivative, thiourea, dithiocarbamate, thioglycolic acid or a derivative thereof is preferable.

  (11) In the asbestos removal method of the present invention according to any one of (9) to (10), the water absorbing agent is an acrylic acid polymer partial alkali salt crosslinked product, an acrylic acid / vinyl alcohol copolymer, It is preferably at least one selected from a cross-linked product of starch and alkali polyacrylate and a cross-linked product of carboxyalkyl cellulose alkali salt.

  (12) In the asbestos removal method of the present invention described in any one of (1) to (11) above, the wet penetrant is used as a wet penetrant in accordance with the water absorption measurement method described in JISP8141. 1% by weight of the added aqueous solution has a water absorption equal to or higher than that of the octylphenol ethylene oxide adduct, and the asbestos fine particles are scattered in the asbestos removal operation with less compound than when the octylphenol ethylene oxide adduct is used. And alkyl naphthalene sulfonate, formalin polycondensate of naphthalene sulfonate, formalin polycondensate of melamine sulfonate, dialkyl sulfosuccinate ester, alkyl disosulfo succinate, alkyl sulfoacetate, higher alcohol sulfate Salt, secondary higher alcohol ethoxy sulfate A wet penetrant containing at least one selected from the group consisting of a salt, a sulfate ester of fatty acid alkylol amide, polyoxyethylene distil phenyl ether, polyoxyethylene tristilphenyl ether is preferable.

    (13) In the asbestos removal method of the present invention according to any one of (1) to (12), an aqueous solution containing 5% by weight of a thickener is measured with a Brookfield digital viscometer. Viscosity is 2000 c. p. s and a water containing 10% by weight of a thickener is a compound having a durometer A hardness of 35 or less after standing in a room temperature for 10 days, comprising an alkali salt of starch glycolate, The thickener is preferably a thickener containing at least one selected from the group consisting of propylene glycol alginate, alkali alginate, and pectin.

(14) In the asbestos removal method according to any one of (1) to (13), the soft binder is di-2 ethylhexyl sulfosuccinate sodium salt concentration of 0.1 wt. Nozzle with a diameter of 1 mm at a flow rate of 35 liters / minute with pressurized water (pressure 650 kg / cm ² ) containing 3% by weight of starch glycolate as a thickener and 5% by weight of a soft binder (in terms of solid content) When sprayed on the asbestos surface of asbestos-containing material located at a distance of 20 cm from the distance, almost no scattering of asbestos fine particles was observed, and water containing 10% by weight of a soft binder was left at room temperature for 10 days. A binder having a durometer A hardness of 35 or less,
Polyvinyl acetate, vinyl acetate / acrylic acid copolymer, vinyl acetate / methacrylic acid copolymer, vinyl acetate / maleic acid ester copolymer, acrylic acid ester copolymer, methacrylic, produced by emulsion polymerization An emulsion selected from a copolymer of acid esters or a copolymer of acrylic acid ester and methacrylic acid ester;
An emulsion in which an aqueous synthetic resin is dispersed in water;
A soft binder containing at least one selected from the group consisting of

  (1) In the first asbestos removal method of the present invention, after applying a composition comprising a drug containing a thickener, a soft binder and a wet penetrant and water to a treatment object containing asbestos. Since asbestos is peeled and removed, when asbestos is removed, asbestos can be peeled and dropped in a relatively large lump so that the fine asbestos does not float in the air. Asbestos lump with a binder is not hardened because it is used (it becomes easy to generate fine asbestos from cracks of asbestos lump etc.), and asbestos is removed in the air when removing asbestos Asbestos removal method that can prevent floating as much as possible can be provided. Therefore, it is possible to provide an asbestos removal method that prevents asbestos inhalation by the asbestos removal worker and environmental pollution caused by minute asbestos in the working environment as much as possible.

  (2) In the method for removing asbestos of the present invention described in (1) above, the metal chelating agent is an asbestos-containing product by making the drug a preferable embodiment of the present invention that further contains a metal chelating agent. Asbestos that adheres and adheres to the iron structure can be removed neatly to such an extent that there is almost no residual amount. Conventionally, with a jig such as a scraper, in reality, asbestos cannot be removed sufficiently, such as parts where it is difficult to scrape asbestos. However, in the present invention, such a portion is also preferable because it can remove asbestos more easily.

  (3) Moreover, the 2nd asbestos removal method of this invention sprays the pressurized water containing the chemical | medical agent containing a thickener, a soft binder, and a wet penetrant from the nozzle to the process target containing asbestos. Asbestos is peeled and removed, so asbestos can be removed more efficiently than when using a jig such as a scraper. Even more, asbestos is likely to float in the air, the method according to the present invention allows the asbestos to peel off in a relatively large lump so as not to float in the air. In addition, since a soft binder is used, the asbestos mass to which the binder is applied does not become hard, and fine asbestos floats in the air when removing asbestos. Asbestos removal method can be provided as much as possible. Further, since the soft binder has a function of reducing the thickening action as much as possible by diluting the thickener with water, the combined effect of both is exhibited.

  (4) Moreover, in the asbestos removal method of the present invention described in the above (3), the drug is preferably a drug further containing a metal chelating agent. In addition to the effects explained, metal chelating agents have the effect of chemically weakening the adhesive bond between the asbestos-containing material and the iron structure, and asbestos applied to the iron structure has almost no residual amount. It is preferable because it can remove asbestos cleanly.

  (5) Moreover, in the 3rd asbestos removal method of this invention, the composition which consists of a chemical | medical agent and water containing a thickener, a soft binder, and a wet penetrant is used as the treatment target containing asbestos. After applying, asbestos is peeled and removed by injecting pressurized water containing a drug containing a thickener, a soft binder and a wet penetrating agent from a nozzle onto the treatment target containing asbestos. In the effect described in (4), it is preferable that fine asbestos can be prevented from floating in the air as much as possible when removing asbestos.

  (6) Moreover, in the asbestos removal method of this invention as described in said (5) item, by making into the preferable aspect of this invention that the chemical | medical agent which comprises the said composition is a chemical | medical agent which contains a metal chelating agent further. In addition to the effect described in the above item (5), the metal chelating agent has an action of chemically weakening the adhesive bonding force between the asbestos-containing material and the iron structure, and asbestos adhered to the iron structure is also effective. Asbestos can be removed cleanly so that the residual amount is almost eliminated.

  (7) Moreover, in the asbestos removal method of the present invention according to any one of (5) and (6), the drug in the pressurized water containing the drug is a drug further containing a metal chelating agent. Since the metal chelating agent is further contained in the pressurized water, the asbestos attached to the iron structure is added to the effect described in the item (5) or (6). It is preferable because it can be removed more cleanly.

  (8) Moreover, the 4th asbestos removal method of this invention is (A) the agent containing a thickener, a soft binder, and a wet penetrant, or (B) a thickener, a soft binder, Pressurized water containing a wet penetrant and a chemical containing a metal chelating agent is sprayed onto a processing object containing asbestos from a nozzle to peel and remove asbestos, and the collected asbestos that has fallen and fallen together with (A) or (B In order to separate the water containing the chemical agent (2), a polymer separation membrane having a pore size of 0.01 to 10 μm is further obtained by filtering through a filter composed of a stainless steel mesh with a mesh opening of 1 to 100 μm. In addition to the effect described in (3) or (4) above, the treatment can be discarded without circulating the pressurized water used for asbestos peeling because the filtrate is recycled as pressurized water. The Compared with the case where it is discarded, the processing cost can be greatly reduced, and the commercial and industrial use of the asbestos removal method using pressurized water such as a water jet can be actually realized.

  (9) Moreover, the 5th asbestos removal method of this invention is (A) the agent containing a thickener, a soft binder, and a wet penetrant, or (B) a thickener, a soft binder, Pressurized water containing a wet penetrant and a chemical containing a metal chelating agent is sprayed onto a processing object containing asbestos from a nozzle to peel and remove asbestos, and the collected asbestos that has fallen and fallen together with (A) or (B In order to separate the water containing), it is filtered through a filter composed of a stainless steel mesh with a mesh opening of 1 to 100 μm, and the filtrate is further filtered through a polymer separation membrane having a pore size of 0.01 to 10 μm. The asbestos residue filtered through the stainless steel mesh and the asbestos residue finely filtered through the polymer separation membrane are collected as asbestos and treated as a melt or specially controlled industrial waste. The filtrate that has been tightly filtered is circulated and used as pressurized water, and further, asbestos-containing wastewater is absorbed by a water-absorbing agent to form a solid and then treated as specially controlled industrial waste. (3), (4) or (8) In addition to the effects described above, it is processed as a collected asbestos or as a specially controlled industrial waste, and asbestos-containing wastewater is solidified and processed as a specially controlled industrial waste. The chance of fine asbestos floating in the air can be sufficiently prevented.

(10) Moreover, in the asbestos removal method of this invention in any one of said (2), (4), (6), (7)-(9) term | claim, a metal chelating agent is used as a flexible binder. Methyl ethyl ester copolymer concentration of acrylic acid and methacrylic acid 5% by weight (solid content conversion), di-2 ethylhexyl sulfosuccinate sodium salt concentration 0.1% by weight as wet penetrant, sodium starch glycolate as thickener Pressurized water (pressure 650 kg / cm ² ) containing 3% by weight of a metal chelating agent and 3% by weight of a metal chelating agent is sprayed onto an asbestos-containing material at a distance of 20 cm from a nozzle having a diameter of 1 mm at a flow rate of 35 liters / minute. Is a compound in which almost no asbestos remains on the surface of the iron plate to which the asbestos is adhered. By making it a preferred embodiment of the present invention that is a metal chelating agent containing at least one selected from the group consisting of a nocarboxylic acid derivative, thiourea, dithiocarbamate, thioglycolic acid or a derivative thereof, these metal chelating agents are The effect of weakening the adhesive bonding force of asbestos attached to the iron structure with the iron structure is excellent, and in the removal of asbestos, the amount of residual asbestos on the iron structure can be further reduced, which is preferable.

  (11) Moreover, in the asbestos removal method of this invention in any one of said (9)-(10) term, a water absorbing agent is acrylic acid polymer partial alkali salt crosslinked material, acrylic acid-vinyl alcohol copolymer. By adopting a preferred embodiment of the present invention, which is at least one selected from a cross-linked product of starch and alkali salt of polyacrylic acid and a cross-linked product of carboxyalkyl cellulose alkali salt, these water-absorbing agents can easily discharge asbestos-containing wastewater. It is preferable that it can be solidified into a solid form.

(12) Further, in the asbestos removal method of the present invention according to any one of (1) to (11) above, the wet penetrant is a wet penetrant according to the water absorption measurement method described in JISP8141. The water absorption of the 0.1% by weight aqueous solution is equal to or higher than that of the octylphenol ethylene oxide adduct, and the asbestos fine particles are less scattered in the asbestos removal operation than when the octylphenol ethylene oxide adduct is used. A compound comprising:
Alkyl naphthalene sulfonate, formalin polycondensate of naphthalene sulfonate, formalin polycondensate of melamine sulfonate, dialkyl sulfosuccinate ester, sulfosuccinate alkyl di-salt, alkyl sulfoacetate, higher alcohol sulfate ester, A book which is a wet penetrant containing at least one selected from the group consisting of secondary higher alcohol ethoxy sulfates, fatty acid alkylol amide sulfates, polyoxyethylene distil phenyl ether, polyoxyethylene tristil phenyl ether According to a preferred embodiment of the invention, these wet penetrants have a large ability to penetrate moisture, thickener, soft binder, or metal chelating agent into the asbestos layer, and fine asbestos floats in the air. To prevent further The preferred can.

(13) Further, in the asbestos removal method of the present invention according to any one of the above items (1) to (12), an aqueous solution containing 5% by weight of the thickener is measured with a Brookfield digital viscometer. Viscosity of 2000 c. p. a compound having a hardness of not less than s and containing 10% by weight of a thickener after standing in a room temperature for 10 days at a durometer A hardness of 35 or less,
By making the preferred embodiment of the present invention a thickener containing at least one selected from the group consisting of alkali starch starch glycolate, propylene glycol alginate, alkali alginate, and pectin, these thickeners are Asbestos surface layer not only has a large thickening effect, but even if the removal work is temporarily interrupted due to a worker's holiday or some accident, etc. If the solidification of the part proceeds, it is preferable that the problem of difficult asbestos removal work can be solved when the work is resumed.

(14) Moreover, in the asbestos removal method of this invention in any one of said (1)-(13) item, a soft binder is di-2 ethylhexyl sulfosuccinate sodium salt concentration 0. Pressurized water (pressure 650 kg / cm ² ) containing 1% by weight, 3% by weight of starch glycolate as a thickener and 5% by weight of soft binder (in terms of solid content) at a flow rate of 35 liters / minute and a diameter of 1 mm When sprayed on the asbestos-containing asbestos surface at a distance of 20 cm away from the nozzle, water containing as much as 10% by weight of asbestos fine particles and 10% by weight of a soft binder was used at room temperature for 10 days. A binder having a durometer A hardness of 35 or less after standing
Polyvinyl acetate, vinyl acetate / acrylic acid copolymer, vinyl acetate / methacrylic acid copolymer, vinyl acetate / maleic acid ester copolymer, acrylic acid ester copolymer, methacrylic, produced by emulsion polymerization An emulsion selected from a copolymer of acid esters or a copolymer of acrylic acid ester and methacrylic acid ester;
An emulsion in which an aqueous synthetic resin is dispersed in water;
By adopting a preferred embodiment of the present invention that is a soft binder containing at least one selected from the group consisting of these, the soft binder is hard to solidify, and when applied, the surface layer portion is It is soft and preferable because it can further prevent fine asbestos from floating in the air during the asbestos removal operation.

  When asbestos-containing material is manually scraped off using a jig such as a scraper or keren, or peeled and removed by spraying with pressurized water or the like, or when removing, a large lump falls but minute asbestos fibers float. There is a possibility of leakage from the cover such as a synthetic resin film surrounding the work site to the outside. In order to suppress or prevent this asbestos scattering, a scattering inhibitor is applied to the asbestos-containing material (dispersion, injection, or spraying is also included in the concept of application in the present invention).

  The functions necessary for the scattering inhibitor are to wet the hard asbestos layer with moisture, the penetration of the agent constituting the scattering inhibitor applied to the surface of the asbestos into the innermost layer, and the scattering inhibitor applied to the surface. Increase the viscosity of the scattering inhibitor so that the constituent chemicals do not fall, and so that the micro asbestos does not float in the air and become a relatively large lump, and the asbestos layer is powdery or Since minute asbestos is generated when it becomes a small lump, it is to give a binding force between asbestos so as to drop into a large lump. However, when the chemical | medical agent which provides binding force solidifies and it will be in a hard state, it will be inevitable that a fine asbestos will generate | occur | produce in the crack part of the lump of a big lump at the time of asbestos removal operation | work. In order to solve this problem, the scattering inhibitor needs to have a flexible and sticky flexible caking property.

  Also, compared to removal work that uses a jig such as a scraper to scrape with human power or a machine, in the removal work that injects pressurized water to impact and peel off the asbestos, there is a tendency for fine asbestos to be scattered more easily. In such asbestos removal by injection of pressurized water, a high-performance fine asbestos scattering inhibitor that suppresses the scattering of fine asbestos is necessary.

  When the asbestos-containing material is scraped off manually using a jig such as a scraper, a certain degree of scattering suppression effect is recognized only by moistening with water containing a wet penetrant. However, the shape is not a flat structure. For example, scattering is unavoidable in removing asbestos layers with a corrugated shape such as folded metal roofing material (square corrugated plate) and an asbestos layer thickness of 20 mm or more. By using it together with the agent, the scattering suppression effect becomes remarkable.

  When the pressurized water is sprayed from the nozzle and impact is applied to the asbestos-containing material, particularly a shock wave (usually, a strong impact and a weaker impact are alternately applied, the peeling effect is improved, but in this way, periodically and alternately In the case of applying a strong and weak impact is referred to as a shock wave here) and removing it by peeling off, it is difficult to suppress scattering of fine asbestos with only a wet penetrant. When a thickener and a wet penetrant are used in combination as an anti-scattering agent, the fine asbestos scattering is improved, but it is difficult to completely suppress it. Since the thickener is usually a water-soluble or water-dispersed substance, the thickening effect is diminished by the penetration of pressurized water.

  However, although the soft binder is water-soluble or water-dispersed, the reduction of the caking effect due to the ingress of water is small, so that the asbestos scattering is suppressed or prevented even when subjected to a water jet shock wave using pressurized water. Great effect. Furthermore, even when using a jig such as a scraper to scrape asbestos-containing materials manually, the scattering of fine asbestos can be suppressed or prevented by an excellent caking effect. Further, in order to promote the penetration of the soft binder into the innermost layer, it is necessary to use a wet penetrating agent together. Furthermore, since the combined use with the thickener has the effect of improving the flexibility of the soft binder and reducing the addition rate of the soft binder, in the present invention, it is necessary to use both of these drug components.

(Method of measuring water absorption of wet penetrant)
According to “Paper and paperboard water absorption test method (Klem method)” described in JIS P8141, the lower end of paper with relatively high water absorption is immersed vertically in water, and the water rises by capillary action after a certain time. The measured height is measured in mm with a scale plate, and the water absorption is obtained.

  In this measurement, the water absorption was measured using a Krem water absorption tester (product number 310, manufactured by Yasuda Seiki Seisakusho) in accordance with JIS P8141.

  NBS Ricoh Co., Ltd. Copier high-quality copy paper type “6200”, standard AOY eyes taped, width 15 ± 1mm, upper and lower ends when gripped with clips equipped with water absorption tester Tape-shaped high-quality copy paper cut into a dimension such that the length of the tape is 200 mm and cut into the predetermined dimension in an aqueous solution at a temperature of 23 ± 1 ° C. with 0.1% by weight of a wet penetrant to be measured. The bottom surface of the aqueous solution is fixed with a clip provided with a water absorption tester so that it is immersed 15 mm deep from the water surface of the aqueous solution, and the upper end is also stopped with the upper clip and left for 10 minutes ± 10 seconds. The height at which the aqueous solution rose was taken as the water absorption of the wet penetrant. In other words, the water absorption measurement method follows the measurement method specified in JISP8141, except that water to which a wet penetrant is added is used.

(Spatter test when removing asbestos)
Folded plate roofing material having a length of 100 mm, a width of 100 mm, and a bottom made of iron. Therefore, asbestos is sprayed 4 to 5 cm in thickness to a steel container with a depth of 50 mm at a shallow bottom and 61 mm at a deep depth], and the height on which the asbestos is sprayed is 2 m when the asbestos is sprayed for more than 10 days. Apply the wet penetrant aqueous solution by spraying at a rate of approximately 2 kg per 1 m ² of asbestos exposed surface by spraying, and let stand for 3 hours at room temperature (all the following drugs are at room temperature) The asbestos particles were removed by spraying with a scraper having a blade portion made of stainless steel and a blade having a lateral length of 36 mm.

(Evaluation method of wet penetrant)
In the above method for measuring the water absorption, a wet penetrant exhibiting a water absorption equivalent to or higher than the octylphenol ethylene oxide adduct described in JP-A-62-178659 as a standard, wherein the asbestos fine particles are scattered. As a result, it was determined that the amount of scattering was less than that in the case where the same amount of the octylphenol ethylene oxide adduct was used at the same concentration. In the present invention, it is preferable to use an acceptable product.

  Wet penetrants suitable for the evaluation method described above include alkyl naphthalene sulfonate, formalin polycondensate of naphthalene sulfonate, formalin polycondensate of melamine sulfonate, dialkyl sulfosuccinate ester salt, alkyl disulfo succinate. Salt, alkyl sulfoacetate, higher alcohol sulfate, secondary higher alcohol ethoxy sulfate, fatty acid alkylol amide sulfate, polyoxyethylene distyryl phenyl ether, polyoxyethylene tristyryl phenyl ether Surfactant is mentioned.

  In the wet penetrant shown in the previous section, the alkyl group R constituting the skeleton is

Where n represents a positive integer. The alkyl group may be linear or branched. When the wet penetrant is a salt, an alkali metal salt or an alkaline earth metal salt is used, and specific examples include sodium, potassium, lithium, calcium, and magnesium salts.

  More preferable specific examples include the following.

  (1) In the alkyl naphthalene sulfonate, the alkyl group preferably has 2 to 5 carbon atoms, particularly preferably an isopropyl group, a butyl group, or an isobutyl group. Those having one or two alkyl groups are preferred. When the alkyl group has 1 carbon atom and 6 or more carbon atoms, the wettability tends to decrease. Accordingly, in the alkyl naphthalene sulfonate, the alkyl group preferably has 2 to 5 carbon atoms. As the salt, sodium salt and potassium salt are preferable.

  (2) The salt in the formalin polycondensate of naphthalene sulfonate is preferably a sodium, potassium, lithium, calcium, or magnesium salt.

  (3) Examples of the salt in the formalin polycondensate of melamine sulfonate include sodium, potassium, calcium, or magnesium salt, and lithium salt.

  (4) The alkyl group of the dialkylsulfosuccinic acid ester salt preferably has 4 to 12 carbon atoms because of good wettability. If the carbon number is less than 4 or 13 or more, the wettability tends to decrease. As the salt, sodium salt and potassium salt are preferable.

  (5) It is preferable that the alkyl group of the sulfosuccinic acid alkyl disalt has 4 to 12 carbon atoms because of good wettability. If the carbon number is less than 4 or 13 or more, the wettability tends to decrease. As the salt, sodium salt and potassium salt are preferable.

  (6) The carbon number of the alkyl group of the alkyl sulfoacetate is preferably in the range of 12 to 18 because of good wettability. If the carbon number is less than 12 or greater than 18, the wettability tends to decrease. As the salt, sodium salt and potassium salt are preferable.

  (7) In the higher alcohol sulfate ester salt, the alkyl group of the higher alcohol segment preferably has 12 to 18 carbon atoms because of good wettability. If the carbon number is less than 12 or greater than 18, the wettability tends to decrease. As the salt, sodium salt and potassium salt are preferable.

  (8) Among the secondary higher alcohol ethoxy sulfates, those represented by the following chemical formula are preferred.

Here, R ₁ and R ₂ represent an alkyl group, n represents an integer of 1 to 12, and M represents an alkali metal.

The total carbon number of R ₁ and R ₂ is preferably in the range of 11 to 17 because of good wettability. If the carbon number is less than 11 or greater than 17, the wettability tends to decrease. Further, n is preferably in the range of 1 to 12 because the foamability is not increased. As an alkali metal of M, sodium or potassium is preferable.

  (9) In the sulfate ester salt of fatty acid alkylol amide, the number of carbon atoms in the fatty acid segment is preferably 12 to 18 because of good wettability. When the number of carbon atoms is 11 or less and 19 or more, the wettability tends to decrease. As the salt, sodium salt and potassium salt are preferable.

  (10) Polyoxyethyne distyryl phenyl ether and polyoxyethylene tristyryl phenyl ether preferably have 4 to 12 moles of addition of ethylene oxide because the wettability is good and the foamability is not too high. When the number of added moles is 3 or less, the wettability tends to decrease, and when the number of added moles is 13 or more, the foamability tends to be too large.

(Method for measuring viscosity of thickener)
In order to investigate the thickening effect of the thickener, the viscosity was measured in an aqueous solution containing 5% by weight of the thickener using a Brookfield digital viscometer “HV-50” manufactured by Techjam Corporation. An aqueous solution containing 5 wt. p. It is preferable to use a thickener that is greater than or equal to s.

  The higher the thickening effect of the liquid as the thickener, the better. However, it is not preferable to solidify the asbestos surface layer. When the work is temporarily suspended for several days to 10 days due to a holiday or other accident while the work is continuing, it is difficult to remove asbestos once the thickener has solidified. For example, thickeners such as polyvinyl alcohol, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, polyurethane and the like are not preferred because they tend to solidify.

(Thickener solidification test method and evaluation method)
As a thickening agent solidification test method, water containing 10% by weight of a thickening agent is filled in an iron container 5 cm long, 10 cm wide and 7 cm deep and left at room temperature for 10 days, and then JIS 6050 In accordance with the hardness test method in (6.2), the hardness is measured using a rubber / plastic hardness meter “SGS 701N” manufactured by Shiro Co., Ltd., the durometer D has a hardness of 10 or less, and the durometer A In the present invention, it is preferable to use those having a hardness of 35 or less. Normally, the measurement accuracy of 10 or less in terms of the durometer D hardness is better when measured with the durometer A hardness. Therefore, if the durometer D has a hardness of 10 or less before being measured and then measured with the durometer A, the evaluation can be performed quickly. Therefore, measurement with the durometer D is not always necessary.

  From the above, in the present invention, as the thickener, the viscosity of an aqueous solution containing 5% by weight of the thickener measured with a Brookfield digital viscometer is 2000 c. p. When the hardness of the water containing 10% by weight or more of the thickener after standing at room temperature for 10 days was 35 or less in terms of durometer A hardness, it was determined to be acceptable. In the present invention, this acceptable product is preferably used.

  Examples of suitable thickeners that have passed the evaluation method described above include starch glycolic acid alkali salts, alginic acid propylene glycol esters, alginic acid alkali salts, and pectin. These are preferable because the asbestos surface layer portion is hardly solidified.

  Examples of the alkali of the alkali salt of the thickener include sodium, potassium, or lithium. Examples of the ester of propylene glycol alginate include methyl, ethyl, propyl, butyl, isopropyl, or isobutyl ester.

The evaluation method for the flexible binder is a folded corrugated sheet roof material having a length of 100 mm, a width of 100 mm, and a bottom made of iron (a square wave plate having a substantially trapezoidal shape (there is no bottom of a trapezoid) whose cross-sections are opposite to each other). Therefore, place the asbestos sprayed 4 to 5 cm thick into a steel container with a bottom depth of 50 mm at a shallow depth of 61 mm, and place it at a height of 2 m, and di-2 ethylhexyl as a wet penetrant. Pressurized water (pressure 650 kg / cm ² ) containing 0.1% by weight of sodium sulfosuccinate salt, 3% by weight of starch glycolate as a thickener, and 5% by weight of a soft binder to be measured (in terms of solid content) ) From the asbestos-containing material 20 cm away from the asbestos surface from the nozzle described below, it is visually determined whether or not asbestos fine particles are scattered when a water stream collides with the asbestos-containing material, and most of the fine particles are scattered If it was not found or not found, it was determined to pass.

FIG. 3 shows a schematic cross-sectional view of a nozzle used for evaluation of the soft binder. In FIG. 3, the left side is the tip (exit) of the nozzle hole, and the hole 2 at the tip of the nozzle 1 has a thin cylindrical shape, and the nozzle hole 3 on the inner side (right side in FIG. 3). Gradually increases in the shape of a truncated cone. 4 is an arrow which shows the introduction direction of pressurized water. The nozzle diameter D of the thin cylindrical hole 2 at the tip of the nozzle hole is 1.0 mm, the length L of the part is 3.5 mm, the total length of the nozzle is 37.5 mm, and the truncated cone part of the nozzle hole 3 The angle α is 13 degrees. The distance between the nozzle and its asbestos-containing material is 20 cm, the drive pump for high-pressure water is a triple plunger type, the motor is 60 Hp (45 kW) three-layer AC 200 V, and the pressure of high-pressure water is 650 kg / cm ² Under the conditions of a flowing water amount of 35 liters / minute, pressurized water was jetted from the lower side 20 cm away from the asbestos surface of the asbestos-containing material, and the soft binder was evaluated.

  As described above, as the binder, those that are easily solidified are unsuitable as the flexible binder. Further, even if it does not solidify, it is not preferable that the surface layer is hard. In other words, in the case of standing drying, the hardened and hardened coating surface layer is a soft binder, and as a softening binder solidification test method, the thickener solidification test method Using a method similar to that described above, water containing 10% by weight of a soft binder is filled in an iron container 5 cm long, 10 cm wide and 7 cm deep, and the hardness of the durometer A after standing at room temperature for 10 days is 35 or less. Was accepted.

  As described above, in the present invention, as the soft binder, almost no scattering of asbestos fine particles is observed in the pressurized water jet test, and in the solidification test method, the hardness of the durometer A is 35 or less. did. In the present invention, it is preferable to use such an acceptable product as the soft binder.

  Examples of the soft binder suitable for the evaluation described above include polyvinyl acetate, vinyl acetate / acrylic acid copolymer, vinyl acetate / methacrylic acid copolymer, vinyl acetate / maleic acid ester copolymer, acrylic An emulsion obtained by emulsion polymerization such as a copolymer of acid esters, a copolymer of methacrylic acid esters, a copolymer of acrylic acid ester and methacrylic acid ester, and an emulsion in which an aqueous synthetic resin is dispersed in water Is mentioned.

  Examples of the acrylic ester, methacrylic ester or maleic ester include methyl, ethyl, propyl or butyl esters.

In the above, the copolymer of acrylates includes at least two or more kinds of copolymers selected from methyl acrylate, ethyl, propyl or butyl ester. , At least two kinds of copolymers selected from methyl methacrylate, ethyl, propyl or butyl ester. Examples of the copolymer of acrylic acid ester and methacrylic acid ester include methyl acrylate, ethyl, propyl or And at least one copolymer selected from butyl ester and at least one copolymer selected from methyl methacrylate, ethyl, propyl or butyl ester. Also, an emulsion in which the above-mentioned aqueous synthetic resin is dispersed in water As an aqueous synthetic resin used for water, an aqueous alkyd resin, Examples include aqueous melamine resins and aqueous acrylic resins.

  The alkyd resin described in the preceding paragraph is composed of a polycondensate of a polyhydric alcohol and a polybasic acid. Examples of the polybasic acid include phthalic anhydride, isophthalic acid, trimellitic acid, adipic acid, azelaic acid, tetrachlorophthalic acid, hexahydrophthalic acid and the like. Examples of the polyhydric alcohol include glycerin, pentaerythritol, ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, and polyethylene glycol. In addition to these, usually a saturated fatty acid having 12 to 18 carbon atoms or an unsaturated fatty acid such as lauric acid, oleic acid, stearic acid, linoleic acid, ricinoleic acid, or a mixture of two or more thereof is used as a modifier. It has been.

  Specific examples of aqueous alkyd resins include polycondensates of fatty acids as modifiers, phthalic anhydride, and pentaerythritol as polyhydric alcohols, and polycondensates of trimellitic anhydride, adipic acid, and ethylene glycol. A suitable example is given.

  The aqueous acrylic resin is a resin obtained by copolymerizing acrylic acid ester, acrylic acid, maleic acid, methacrylic acid, etc., and water-solubilizing a hydroxyl group as a salt with ammonia or amine.

  The aqueous melamine resin is obtained by reacting trimethylolmelamine and methanol with oxalic acid by heating, concentrating and removing methanol after cooling, and then neutralizing with amine.

  Moreover, the metal chelating agent mentioned above chemically weakens the adhesive bonding force between the asbestos and the iron structure sprayed with the asbestos, and promotes peeling between the iron structure and asbestos. Therefore, there is little asbestos remaining in the iron structure, and asbestos can be removed cleanly. Since asbestos that is difficult to scrape with a jig such as a scraper can be chemically removed, it is preferable to use a metal chelating agent when removing asbestos adhering to the iron structure.

The evaluation method of the metal chelating agent is a folded corrugated plate roof material having a length of 100 mm, a width of 100 mm, and a bottom made of iron (a square corrugated plate having a substantially trapezoidal shape (there is no bottom of a trapezoid) whose cross sections are opposite to each other). Therefore, asbestos is blown to an iron container of 50 mm at a shallow bottom and 61 mm deep at a depth of 4 to 5 cm, and the asbestos is sprayed on the side where the asbestos is blown for 10 days or more. Placed in position, the soft-binding agent described in Comparative Example 3 as a soft binder, a methyl ethyl ester copolymer concentration of acrylic acid and methacrylic acid of 5% by weight (in terms of solid content), di-2ethylhexyl as a wet penetrant Pressurized water (pressure 650 kg / cm ² ) containing a sodium sulfosuccinate salt concentration of 0.1% by weight, a sodium glycol glycolate concentration of 3% by weight as a thickener and a metal chelating agent concentration of 3% by weight to be measured at a flow rate of 35 l / 2 minutes from the asbestos surface of the asbestos-containing material under the same conditions using the same nozzle as the evaluation method of the soft binder. Injected from below the cm, asbestos is peeled and dropped, the amount of asbestos remaining on the surface of the iron container is visually determined, and there is almost no remaining asbestos and the surface of the iron container is in a clean state is passed . In the present invention, it is preferable to use an acceptable product.

  Examples of the metal chelating agent suitable for the evaluation in the preceding paragraph include a hydroxylaminocarboxylic acid derivative, thiourea, dithiocarbamate, thioglycolic acid or a derivative thereof.

  The general formula for hydroxylamine derivatives is

Indicated by Here, R ₁ and R ₂ represent an alkyl group having 2 to 12 carbon atoms, and A is a phenyl group.

  The structural formula of thiourea is

Indicated by

Dithiocarbamate includes diethylamine and piperazine.
Examples of the diethylamine dithiocarbamate include diethylamine-N-carbothioate salts represented by the following chemical formula.

Here, M represents an alkali metal.
Examples of the alkali metal include sodium, potassium, and lithium.

  Examples of the piperazine-based dithiocarbamate include piperazine-1.4-dicarbodithioate disalts represented by the following chemical formula.

Here, M represents an alkali metal.
Examples of the alkali metal include sodium, potassium, and lithium.

  In thioglycolic acid or its derivatives, thioglycolic acid is also called mercaptoacetic acid and is represented by the following chemical formula.

  Examples of the thioglycolic acid derivative include ammonium thioglycolate, 2-ethylhexyl thioglycolate, methoxybutyl thioglycolate and the like.

  As already described, the necessary functions of the asbestos scattering inhibitor to be contained in the pressurized water for water jets require wet permeability, thickening, and flexible caking properties, which are necessary characteristics of the scattering inhibitor. However, the importance of each component to be used is slightly different from the asbestos removal method that does not apply pressurized water injection using a jig such as a scraper. Therefore, in the present invention, a chemical composition for preventing asbestos scattering used for removal work that is scraped off by human power or machine using a jig such as a scraper (however, the metal chelating agent is not directly related to the scattering preventing action. The drug composition consisting of a wet penetrant, thickener, and soft binder, excluding) is referred to as a “scattering inhibitor” when it is necessary to distinguish between the explanations. In the following, the same chemical composition for preventing asbestos scattering used for removing work to give off will be described as “scattering preventing agent” when it is necessary to distinguish between the explanations. It is a name (name) that is used in distinction in order to omit deciding whether the drug composition is used, and does not mean that the drug composition is necessarily different.

  In the anti-scattering agent, the flexible caking property is the most important, followed by the thickening, and the wet permeability is a complementary function that demonstrates the former two capabilities. That is, combined use with a wet penetrant is more effective than using a soft binder alone, and combined use with a wet penetrant is more effective than using a thickener alone. Further, it is preferable to use a soft binder and a thickener in combination because the usage rate of the soft binder can be reduced.

  Therefore, the types and contents of wet penetrants, thickeners and soft binders used as scattering inhibitors applied to asbestos-containing materials before asbestos removal work and metal chelating agents used as needed, and for water jets The type and content of wet penetrants, thickeners and soft binders used as anti-scattering agents to be contained in pressurized water or metal chelating agents used as required are the shape and hardness of asbestos-containing materials, and when pressurized water is used. It may be determined appropriately depending on conditions such as the degree of pressurization of the pressurized water and the flow rate, and is not necessarily the same.

  When removing asbestos with water jet pressurized water, a large amount of water is used. As described above, recovery and reuse of pressurized water for water jet is extremely important for profit. Furthermore, it would be advantageous in profitability to be able to recycle chemicals added to water simultaneously with water recycling. Therefore, it is preferable to select an agent that can be the same type of the asbestos scattering inhibitor and the scattering inhibitor as described above, and that the content can be approximated as much as possible. It has been found that the specifically described compounds of the wet penetrant, thickener and soft binder described above are extremely useful as satisfying this condition.

  Wet penetrant, thickener and soft binder, metal chelating agent used as necessary, and water use ratio, the wet penetrant is preferably 0.05 to 5% by weight based on the total weight of these, More preferably 0.1 to 1.5 wt%, thickener is preferably 0.5 to 10 wt%, more preferably 1 to 5 wt%, and soft binder is preferably 0.5 to 10 wt%. % By weight, more preferably 1 to 5% by weight. Moreover, when using a metal chelating agent, the usage-amount of a metal chelating agent becomes like this. Preferably it is 0.5-8 weight%, More preferably, it is 1-4 weight%.

  When adopting a method that removes asbestos by jetting pressurized water, the asbestos that has been peeled off by jetting pressurized water, including water containing the above-mentioned chemicals that have been used with the removed asbestos, is sucked under reduced pressure and collected asbestos tank Then, the mesh opening is filtered through a filter made of a stainless net having a mesh size of 1 to 100 μm. Filtration is not limited to one time. The first stage is filtered with a filter having a mesh opening of 80 to 100 μm (for example, 88 μm in a commercial product), and the second stage is having a mesh opening of 51 to 70 μm (commercially available). For example, the filter has a mesh opening of 41 to 50 μm (for example, 44 μm in a commercial product), and the fourth stage has a mesh opening of 30 to 40 μm (for example, 37 μm in a commercial product). It is also preferable to perform filtration using a filter having a fine mesh opening sequentially.

  The stainless steel filter on which the collected sbestos adhere as a filtration residue can be completely regenerated by backflow cleaning in which compressed air and water are caused to flow backward in the direction opposite to the direction of filtrate passage.

  According to the method of the present invention, collected asbestos peeled off in a lump form from a building or the like is filtered with the above stainless steel filter. However, a single asbestos fiber is usually, for example, 0.02 μm in diameter and 0.3 μm in length. Because it is an ultrafine particle, it cannot be completely captured by a stainless steel filter. In order to capture this, it is preferable that ultra-fine filtration is performed with a polymer separation membrane having a pore diameter of 0.01 to 10 μm, preferably 0.05 to 5 μm, so that fine asbestos is reliably collected. The pore size of the polymer separation membrane is usually not uniform and has a distribution from small to large pores. These polymer separation membranes can be appropriately selected and used according to the purpose.

  As the polymer separation membrane, a microfiltration membrane capable of separating fine particles and microorganisms in the range of 0.01 to 10 μm, preferably 0.05 to 5 μm, and a material in the range of 2 nm to 0.1 μm can be separated. Examples include ultrafiltration membranes and reverse osmosis membranes that can separate materials smaller than 2 nm.

  In the method of the present invention, the fine asbestos can be almost collected by the precision separation membrane of the polymer separation membrane. Further, the ultrafiltration membrane can be completely collected. Membranes having a filtration function of 0.02 to 0.2 μm aiming at an intermediate region between microfiltration and ultrafiltration are also commercially available, and even this can completely collect minute asbestos.

  These polymer separation membranes may be appropriately selected and used according to the necessity of separation.

  These polymer separation membranes can also be regenerated without clogging by backwashing.

  As the polymer constituting the microfiltration membrane, polyvinyl alcohol, cellulose acetate, polyethylene, polypropylene, polytetrafluoroethylene and the like are used. Polyvinyl alcohol is used for the polymer separation membrane for the intermediate region between the ultrafiltration membrane and the microfiltration membrane. Polysulfone is used for the ultrafiltration membrane. Examples of the reverse osmosis membrane include cellulose acetate, polyacrylonitrile, polyvinyl chloride, polysphon, aromatic polyamide, ceramics and the like. These separation membranes include not only single component membranes but also composite membranes. For example, many composite membranes obtained by interfacially polymerizing aromatic polyamide on the surface of a polysulfone porous membrane are preferably used.

  When filtered through an ultrafiltration membrane, the wetting penetrant, thickener, soft binder and metal chelating agent used for the scattering inhibitor or anti-scattering agent can be almost completely removed.

  If you want to reuse the wet penetrant, thickener, soft binder, and metal chelating agent, which are the components in the high-pressure water sprayed to the asbestos-containing material, when you want to reuse the filtered recovered water, the first method In the asbestos peeling operation, there is a method in which the filtrate filtered through a filter composed of a stainless steel mesh having a mesh opening of 1 to 100 μm is circulated and used as pressurized water as it is in a closed system. In this case, the chemical is not removed by filtration, and pressurized water containing fine asbestos is circulated and used.

  In the second method, most of the fine asbestos can be removed by filtration using a microfiltration membrane without using an ultrafiltration membrane after filtration with the above stainless steel mesh filter. Most of the binder and metal chelating agent can be recovered and reused.

  We want to completely remove the water wet penetrant, thickener, soft binder and metal chelating agent used as needed in the second method above, If it is necessary to remove it, it may be filtered using an ultrafiltration membrane.

  FIG. 1 shows the asbestos removal process. FIG. 1 is a process explanatory flowchart of one embodiment of the asbestos removal method of the present invention. In FIG. 1, in step 1, an asbestos scattering inhibitor is applied to a treatment object containing asbestos, if necessary, a composition comprising a drug containing a metal chelating agent and water. In step 2, asbestos scattering inhibitor As required, pressurized water containing a chemical containing a metal chelating agent is sprayed from the nozzle onto the treatment object containing asbestos to peel off asbestos, falling asbestos and the used pressurized water Aspirate the vacuum. In step 3, the pressurized water (drainage) containing asbestos and the like sucked under reduced pressure in the step 2 is filtered through a filter composed of a stainless mesh with a mesh opening of 1 to 100 μm, and at least one part or all of the filtrate is further reduced to 0. Fine filtration is performed with a polymer separation membrane having a pore size of 0.01 to 10 μm, and the asbestos of the filtration residue is disposed of as indicated by reference numeral (A) (melting treatment or processing as specially controlled industrial waste). In step 4, the water containing the drug filtered in step 3 is recovered and returned to step 2 to be reused as pressurized water. When the filtrate filtered only with the stainless steel mesh is recovered and returned to step 2 to be reused as pressurized water, the recovered pressurized water contains fine asbestos that could not be captured by the stainless steel filter in addition to the drug. .

  FIG. 2 is a detailed explanatory diagram of step 3 showing the part of step 3 in more detail.

  In FIG. 2, the first stage is filtration through a stainless mesh filter having an opening of 1 to 100 μm. As shown in the block on the right side of the first stage in FIG. 2, the filtrate is composed of a wet penetrant, a thickener, a soft binder, and a metal chelator and fine asbestos fibers used as necessary. It becomes the aqueous solution containing. By strictly controlling this filtrate so that minute asbestos does not leak, it can be reused as pressurized water containing an asbestos scattering inhibitor and a metal chelating agent used as necessary, as shown in FIG.

  In the second stage, a part or all of the filtrate obtained in the first stage is subjected to microfiltration with a polymer separation membrane capable of capturing fine particles in the range of 0.01 to 10 μm, preferably 0.05 to 5 μm. In the filtrate, an aqueous solution containing a wet penetrant, a thickener, a soft binder, and a metal chelate used as necessary and not containing fine asbestos fibers is obtained.

  Drainage after asbestos removal work was completed and the workplace was cleaned, drainage that was backwashed to regenerate the filter composed of stainless steel, drainage that was backwashed to regenerate the polymer separation membrane, and sealed pipes and tanks Washed wastewater and other water that may contain asbestos are collected in a disposal container (not shown), and solidified by adding a superabsorbent water absorbent as shown in step 5 of FIG. This completely prevents the leakage of minute asbestos. The fine asbestos-containing waste solidified with the water-absorbing agent is displayed at a position indicated by a symbol (B) in FIG. This is treated as specially controlled industrial waste.

  In the above, the melting treatment for detoxifying the recovered asbestos is usually carried out as it is or after asbestos is melted and solidified with an additive which becomes an appropriate melting point depressant (flux). This is a treatment in which the crystal structure is changed and rendered harmless. When an additive such as a melting point depressant is not used, it is usually melted at 1500 or more in an electric furnace or the like. When an additive such as a melting point depressant is used, it can be melted at a lower temperature, which is advantageous in terms of cost.

  For example, as described in JP-A-9-206726, asbestos-containing materials are rendered harmless by mixing incineration ash of municipal waste with asbestos, heating at 600-1700 ° C., and reaction sintering. Can be used. While the main components of asbestos are Si and Mg, the main components of incineration ash of municipal waste contain a large amount of Ca, Na, K and Si, which are components that easily generate a glass phase (liquid phase). It is out. Therefore, a method of detoxifying asbestos by heat-treating the mixture of both at a low temperature of 600 to 1700 ° C. can be employed.

  As a method that seems to be similar to this, industrial waste such as sludge, mineral rhinoceros, burning husks, printed circuit boards, pad scraps, exhaust catalysts, and metal scraps is melted in a horizontal furnace as described in JP-A-2005-181212. And while forming a slag bath in a hot water pool part, the method of throwing in asbestos into a slag bath and dissolving in a slag bath and making it harmless is also employable.

Japanese Patent No. 3120308 discloses a method of adding CaF ₂ to asbestos and melting it to make it glassy. Furthermore, calcium fluoride can also be used as a melting agent.

  In addition, as shown in Japanese Patent Application Laid-Open No. 2005-168632, when disposing of chlorofluorocarbon, asbestos is mixed with chlorofluorocarbon decomposition products generated by a method of detoxifying chlorofluorocarbon by thermally decomposing chlorofluorocarbon by plasma treatment. Moreover, a method of detoxifying asbestos by low-temperature heat treatment at about 600 ° C. can also be employed.

  In addition, “specially controlled industrial waste” when treated as specially controlled industrial waste mentioned above is the law on waste disposal and cleaning in Japan (Law No. 137, December 25, 1970). : Article 18, Paragraph 5 of May 18, 2005, Law No. 42). Therefore, it will be processed in accordance with this law and related government ordinances.

  As related government ordinances, Article 10-17 of the Law Enforcement Ordinance on Waste Disposal and Cleaning (Ministry of Health and Welfare Ordinance No. 35, September 23, 1971, Final Revision: Ministry of Environment Ordinance No. 11 of April 19, 2005) There is a provision in (6) of (i) about melting facilities and other processing facilities suitable for disposal of asbestos. Article 10-17-2 (1) (1) shows the provisions for specially controlled industrial wastes for landfill disposal.

  Regarding the standards for the collection, transportation, and disposal of specially managed industrial waste, the Law Enforcement Ordinance on Waste Disposal and Cleaning (September 23, 1971, Decree No. 300, final revision: August 15, 2005) Article 6-5-3 of Decree No. 277) stipulates the prevention of scattering, double packing with water-resistant materials, solidification processing, etc. when landfilling waste asbestos and the like.

  As described above, in the case of disposal as specially controlled industrial waste, the specially controlled industrial waste that has been treated in accordance with the provisions of these laws and ordinances is landfilled according to the methods specified above. Will be disposed of. Usually, it is outsourced to a contractor who treats this specially managed industrial waste. In the present invention, processing as specially controlled industrial waste includes entrusting to a contractor that processes specially controlled industrial waste.

  Moreover, as an evaluation method of the water-absorbing agent (also referred to as a water-absorbing resin) used for solidifying the waste water, water that is 5 times or more the weight of the water-absorbing agent can be absorbed, and a solid-state one is accepted. In the present invention, it is preferable to use an acceptable product.

  Examples of water-absorbing agents that meet the above evaluation include acrylic acid polymer partial alkali salt cross-linked products, acrylic acid-vinyl alcohol copolymer, starch and polyacrylic acid alkali salt cross-linked products, and carboxyalkyl cellulose alkali salt cross-linked products. Can be mentioned.

  A crosslinked product of a partial alkali salt of an acrylic acid polymer is a method of polymerizing polyacrylic acid or an alkali salt thereof to form a linear polymer and then crosslinking with a crosslinking agent, and an acrylic acid or alkali salt of acrylic acid. And a crosslinking agent monomer are simultaneously copolymerized to obtain a cross-linked product of a partial alkali salt of polyacrylic acid, and those produced by any method can be suitably used. The partial alkali salt is a product obtained by partially converting the hydrogen of the carboxyl group (—COOH) of acrylic acid into an alkali metal salt. Examples of the alkali metal of the alkali metal salt include sodium, potassium, and lithium. A bifunctional monomer is used as the crosslinking agent. For example, maleic acid, fumaric acid, itaconic acid, citraconic acid and anhydrides of these acids, ethylene glycol dimethacrylate, ethylene bisacrylamide and the like can be used.

  The acrylic acid-vinyl alcohol copolymer can be obtained by copolymerizing vinyl acetate and methyl acrylate and saponifying with an alkali.

  The cross-linked product of starch and polyacrylic acid alkali salt is obtained by graft polymerization of alkali acrylate salt such as sodium salt or potassium salt to starch and copolymerizing a bifunctional monomer that becomes a cross-linking agent at the time of polymerization. Obtained by crosslinking. As the crosslinking agent or bifunctional monomer, those described above can be used.

  Examples of the alkyl group of the cross-linked carboxyalkyl cellulose salt include a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, and an isobutyl group. For example, carboxymethyl cellulose can be obtained by reacting cellulose and monochloroacetic acid. When this is crosslinked with a crosslinking agent, a crosslinked carboxymethyl cellulose is obtained. As the crosslinking agent, those described above can be used. Examples of the alkali salt include sodium salt and potassium salt.

  By treating the asbestos-containing water solidified with the water-absorbing agent as described above as a specially controlled industrial waste as described above at a specially managed industrial waste disposal site, the asbestos-containing water can be safely treated without leakage.

  In the examples and comparative examples described below, first, the periphery of the asbestos removal site is completely surrounded by a synthetic resin film such as a polyvinyl chloride film, and an openable / closable partition door is attached to the entrance to the outside. The vacuum at the work site is reduced by the vacuum pump, and the dust removal device is operated to ensure that even if floating asbestos is generated by the asbestos removal work, it will not leak to the outside.

  Asbestos removal workers should work in a completely dust-proof position to prevent asbestos from entering the body, such as protective clothing, respiratory protective equipment including gas and dust masks, helmets, and gloves.

  Since the above matters are common to the following examples and comparative examples, the description is omitted in each of the examples and comparative examples.

[Comparative Example 1]
A case where the wet penetrant alone is used as one component of the scattering inhibitor will be described. As the wet penetrant, the water absorption is measured by the wet penetrant measurement method described above, and di-2ethylhexylsulfosuccinate sodium salt made by Takemoto Yushi is used among the surfactants passed by the wet penetrant evaluation method, Asbestos sprayed iron folded plate roofing material composed of this and water [substantially trapezoidal shape with cross-sections facing each other upside down (there is no trapezoidal base: the distance corresponding to the height between the top and bottom of the trapezoid is 11 mm) Asbestos on the inner side of the corrugated plate consisting of a repetition of 4 to 5 cm in thickness is placed at a height of 2 m with the asbestos sprayed side down and sprayed from below. Apply at a rate of approximately 2 kg per 1 m ² , leave at room temperature (all the following drugs are at room temperature) for 3 hours, and then spray manually with a scraper Asbestos removal was performed. The wetting effect of water was observed at a concentration of 0.05% by weight of the wet penetrant, and the wetting effect was not changed at a concentration of 0.5% by weight or more. Therefore, the wet penetrant with a concentration of 0.1% by weight was applied under the above conditions, and after 3 hours, the asbestos was removed with a scraper having a blade portion made of stainless steel and a blade having a lateral length of 36 mm. Small asbestos was scattered with the fall of large and small chunks.

[Comparative Example 2]
Of those that have passed the thickener evaluation method described above, sodium starch glycolate made by Nissho Chemical is selected and mixed with water. At a concentration of 5% by weight, the thickening effect is sufficient, but at a concentration of 0.5% by weight. It was insufficient, and a thickening effect was observed at 1% by weight. Therefore, the asbestos sprayed iron folded plate roofing material used in Comparative Example 1 is an asbestos scattering inhibitor composed of a mixture of 3% by weight of the above thickener and water containing 0.1% by weight of the wet penetrant described in the preceding paragraph. The same amount was applied under the above conditions, and after leaving at room temperature for 3 hours, asbestos removal work was performed with a scraper similar to the scraper used in Comparative Example 1. As a result, small lumps were reduced and large lumps dropped, resulting in small asbestos. Although the scattering was clearly reduced, there was still a slight scattering of asbestos. The thickener alone was poorly penetrated into the interior, and the amount of fine asbestos was scattered. Therefore, the combined effect of the thickener and the wet penetrant was recognized.

[Comparative Example 3]
Among those that have passed the above-described evaluation method for soft binder, Dai Nippon Paint's methyl acrylate, ethyl acrylate, methyl methacrylate and ethyl methacrylate copolymer (hereinafter referred to as acrylic acid and methacrylic acid). A dispersion inhibitor comprising a mixture of 5% by weight of a soft binder and 0.1% by weight of a wet penetrant is selected as a comparative example. As a result of applying the same amount to the asbestos sprayed iron folded roof material used in 1 under the same conditions, leaving it at room temperature for 3 hours, and then removing the asbestos with the scraper similar to the scraper used in Comparative Example 1. The number of small asbestos splattered decreased, and the scattering of fine asbestos was clearly reduced, but a slight splattering of asbestos was still observed. Residual asbestos was observed on the surface of the iron folded plate roof material, which is an iron structure.

[Example 1]
3% by weight of a soft binder acrylic acid and methacrylic acid methyl ethyl ester copolymer emulsion described in Comparative Example 3, 2% by weight of thickener sodium starch glycolate of Comparative Example 2, and a wet penetrant Di-2 The same amount of asbestos scattering inhibitor composed of a mixture with water containing 0.1% by weight of ethylhexylsulfosuccinate sodium salt was applied to the asbestos-sprayed iron folded-plate roofing material used in Comparative Example 1 under the same conditions, and 3% at room temperature. After being left for a period of time, the removal work was performed using the same scraper as the scraper used in Comparative Example 1. As a result, there were few small lumps, and most of the large lumps dropped and almost no scattering of fine asbestos was observed.

  The combined effect of the soft binder, thickener and wet penetrant was clearly recognized. Moreover, in this case, the addition rate of a soft binder and a thickener can be reduced. Residual asbestos was observed on the surface of the iron folded plate roof material, which is an iron structure.

[Example 2]
The ammonium thioglycolate manufactured by Sasaki Chemical Co., Ltd. was selected from those that passed the evaluation method for the metal chelating agent described above, and 3% by weight of the soft binder described in Example 1, 2% by weight of the thickener, and 0% of the wet penetrant. .1 wt%, metal chelate agent 2 wt%, and water containing composition, mixed solution of scattering inhibitor and metal chelate used in Comparative Example 1 asbestos sprayed iron folded plate roofing material under the same conditions After applying and leaving at room temperature for 3 hours, the removal work was done with a scraper similar to the scraper used in Comparative Example 1. As a result, most of the large lumps dropped and almost no scattering of fine asbestos was observed. Asbestos was clean with no asbestos remaining on the surface of the steel folded-plate roof material, which is an iron structure.

[Comparative Example 4]
The same as the asbestos-sprayed iron folded plate roofing material used in Comparative Example 1 as the asbestos scattering inhibitor, the scattering inhibitor composed of 0.1% by weight of the wet penetrant di-2ethylhexylsulfosuccinate sodium salt and water. Apply the same amount under the conditions, leave it at room temperature for 3 hours, and then add 0.1% by weight of the wet penetrant as an anti-scattering agent to be added to the pressurized water, and the pressurized water at a pressure of 650 kg / cm ² and a flow rate of 30 liters / minute As a result of the removal work by spraying the asbestos-sprayed iron folded roofing material from the lower side where the nozzle diameter D shown in FIG. 3 is 20 cm away from the nozzle having a diameter of 1 mm as shown in FIG. Dropped and a large amount of fine asbestos was scattered.

[Comparative Example 5]
Asbestos sprayed iron folded board using Comparative Example 1 as a mixed aqueous solution containing 3% by weight of the thickener sodium starch glycolate and 0.1% by weight of the wet penetrant sodium di-2ethylhexylsulfosuccinate as an asbestos scattering inhibitor The same amount is applied to the roofing material under the same conditions, and after standing at room temperature for 3 hours, it contains 3% by weight of the same thickener and 0.1% by weight of the same wet penetrant as an anti-scattering agent added to the pressurized water. The pressure is 650 kg / cm ² and the flow rate is 30 liters / minute. The nozzle diameter D shown in FIG. 3 is sprayed from the nozzle 20 cm away from the nozzle having a diameter of 1 mm to the asbestos-attached side of the asbestos-sprayed iron folded roofing material. As a result of the removal work of adhering asbestos, large and medium lumps dropped, but a small amount of fine asbestos was also observed. The surface of the iron folded-plate roof material, which is an iron structure, is cleaner than the manual work of scraping with a scraper, but asbestos residue still exists.

[Comparative Example 6]
As an asbestos scattering inhibitor, 5% by weight of a soft binder acrylic acid / methacrylic acid methyl ethyl ester emulsion, 0.1% by weight of a wet penetrant di-2-ethylhexyl sulfosuccinate sodium salt and water As an anti-scattering agent to be added to pressurized water after applying the same amount to the asbestos-sprayed iron folded plate roofing material used in Comparative Example 1 under the same conditions and leaving it at room temperature for 3 hours, 3 containing 5% by weight of the same soft binder and 0.1% by weight of wet penetrant, the pressure of 650 kg / cm ² and the flow rate of 30 liters / minute, the nozzle diameter D shown in FIG. As a result of spraying on the asbestos adhesion side of the asbestos-sprayed iron folded plate roofing material from the lower side 20 cm away from the 1 mm nozzle, and removing the adhered asbestos, large and medium lump fell. Scattering of asbestos was also observed a little. The surface of the iron folded-plate roof material, which is an iron structure, is cleaner than the manual work of scraping with a scraper, but asbestos residue still exists.

[Example 3]
3% by weight of a soft binder acrylic acid and methacrylic acid methyl ethyl ester as an asbestos scattering inhibitor, 2% by weight of thickener sodium starch glycolate, wetting penetrant di-2ethylhexyl sulfosuccinate sodium salt Is applied to the asbestos-sprayed iron folded plate roofing material used in Comparative Example 1 in the same amount under the same conditions, and left at room temperature for 3 hours, and then pressurized water. As an anti-scattering agent to be added, 3% by weight of the same soft binder as described above, 2% by weight of the same thickener as described above, and 0.1% by weight of the same wet penetrating agent as described above, pressurized water at a rate of flow 30 l / min at a pressure 650 kg / cm ² and a nozzle diameter D is from below away 20cm from the nozzle with a diameter of 1mm as shown in FIG. 3, the sprayed asbestos iron folding plate roofing asbestos The terminating result of removal work of adhesion asbestos by injecting a large mass was excellent without scattering of fine asbestos mainly. The combined effect of three types of drugs, a soft binder, a thickener, and a wet penetrant, is observed. Moreover, since a thickener and a soft binder are used together, a soft binder can be reduced. The surface of the iron folded-plate roof material, which is an iron structure, is cleaner than the manual work of scraping with a scraper, but asbestos residue still exists.

[Example 4]
In addition to the scattering inhibitor and scattering inhibitor used in Example 3, as a metal chelating agent, an aqueous solution containing 2% by weight of ammonium thioglycolate in the scattering inhibitor and the scattering inhibitor, respectively, and similar pressurized water As a result of removing the asbestos adhering to the asbestos-sprayed iron folded plate roofing material in the same manner as in Example 3, it was found that a large lump was mainly dropped and no fine asbestos was scattered. Moreover, the surface of the iron folded-plate roof material which is an iron structure was clean, and the asbestos residue was not recognized.

[Example 5]
In Example 4, the water containing the asbestos and chemicals that were peeled off by the injection of pressurized water was sucked under reduced pressure with a vacuum pump and stored in a collection asbestos tank. In the “MS filter”, the first stage is an 88 μm aperture filter, the second stage is a 63 μm aperture filter, the third stage is a 44 μm aperture filter, and the fourth stage is a filter. Filtration was performed using a filter having an opening of 37 μm. The filtered asbestos residue is sent to a melting treatment plant to be melted or processed as specially controlled waste as described in Step 3 in FIG. 1 as asbestos disposal. As a result of analyzing the chemical content of the filtered filtrate, such as a wet penetrant, a thickener, a soft binder, and a metal chelating agent, the filtrate was contained with almost no difference from the initial addition rate. In addition, it contained a small amount of small asbestos fibers. By strictly controlling the recovered water so as not to leak small asbestos fibers in a closed system, the recovered water could be reused as pressurized water containing an asbestos scattering inhibitor and a metal chelating agent as shown in FIG.

[Example 6]
The filtrate filtered through the “MS filter” described in Example 5 contains a small amount of small asbestos fibers. By continuing to recycle the filtrate as pressurized water, the content of small asbestos fibers accumulates in the recycled pressurized water. come. Therefore, the small asbestos fibers can be completely removed by further finely filtering the filtrate filtered through the stainless steel “MS filter” of Example 5 using a polymer separation membrane.

  That is, the filtrate filtered through the stainless steel “MS filter” of Example 5 was further filtered using a “SF filter” made of polyvinyl alcohol manufactured by Kuraray Co., Ltd., and adhered asbestos in the same manner as in Example 5. Was removed. The “SF filter” corresponds to the intermediate region between microfiltration and ultrafiltration, and can separate fine particles of 0.02 to 0.2 μm, so the small asbestos fibers contained in the filtrate filtered with the “MS filter” are completely In addition, water containing chemicals such as a wet penetrating agent, a thickener, a soft binder, and a metal chelating agent was recovered and recycled as pressurized water.

[Example 7]
In Example 6, at the stage where the removal work of adhering asbestos was completed, the wastewater that was cleaned in the workplace, the wastewater that was backwashed to regenerate the stainless steel “MS filter”, and the polymer separation membrane microfiltration “SF filter” In order to regenerate, wastewater that was washed back-flow, wastewater that was washing closed pipes and tanks, and other water that could contain asbestos were collected in waste containers. Using the acrylic acid polymer partial sodium salt cross-linked product “Aquakeep” (trade name) manufactured by Sumitomo Seika as a water-absorbing agent, as a result of adding the water-absorbing agent with a weight of 1/10 of the water weight in the container, Water was completely absorbed and solidified. This was treated as special management waste.

  INDUSTRIAL APPLICABILITY The present invention can provide an asbestos removal method in which asbestos scattering is less likely to occur, and therefore can be effectively used as a method for removing asbestos from buildings and structures in which asbestos is used.

The process explanatory flowchart of one Embodiment of the asbestos removal method of this invention. FIG. 3 is a detailed explanatory diagram of step 3 in FIG. Sectional drawing of the nozzle for injecting pressurized water on the asbestos surface of an asbestos containing material used in the case of evaluation of a soft binder and a metal chelating agent.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nozzle 2 Hole at the front-end | tip part of the hole of Nozzle 1 Nozzle hole inside 2 (right direction of FIG. 3)

Claims (6)

An asbestos removal method in which asbestos is peeled and removed after a composition comprising a thickener, a soft binder, a wet penetrant , and a drug containing a metal chelating agent and water is applied to a treatment target containing asbestos. Because
The viscosity of the aqueous solution containing 5% by weight of the thickener as measured by a Brookfield digital viscometer is 2000 c. p. a compound having a hardness of not less than s and containing 10% by weight of a thickener after standing in a room temperature for 10 days at a durometer A hardness of 35 or less,
It is a thickener containing at least one selected from the group consisting of alkali starch starch glycolate, propylene glycol alginate, alginic acid alkali salt, pectin,
The soft binder has a di-2-ethylhexyl sulfosuccinate sodium salt concentration of 0.1% by weight as a wet penetrant, a starch glycolate soda concentration of 3% by weight and a soft binder concentration of 5% by weight (solid content). When the pressurized water containing (converted) (pressure 650 kg / cm ² ) is sprayed to the asbestos-containing asbestos surface at a distance of 20 cm from a nozzle with a diameter of 1 mm at a flow rate of 35 liters / minute, most of the asbestos particles are scattered. A binder having a durometer A hardness of 35 or less after standing at room temperature for 10 days, water that is not seen and contains 10% by weight of a soft binder,
Polyvinyl acetate, vinyl acetate / acrylic acid copolymer, vinyl acetate / methacrylic acid copolymer, vinyl acetate / maleic acid ester copolymer, acrylic acid ester copolymer, methacrylic, produced by emulsion polymerization An emulsion selected from a copolymer of acid esters or a copolymer of acrylic acid ester and methacrylic acid ester;
An emulsion in which an aqueous synthetic resin is dispersed in water;
A soft binder containing at least one selected from the group consisting of:
The wet penetrant has a water absorbency of an aqueous solution to which 0.1 wt% of the wet penetrant is added according to the method for measuring water absorbency described in JIS P8141, and is asbestos as octylphenol ethylene oxide adduct. Scattering of asbestos fine particles in the removal operation is a compound that is less than when using the octylphenol ethylene oxide adduct,
Alkyl naphthalene sulfonate, formalin polycondensate of naphthalene sulfonate, formalin polycondensate of melamine sulfonate, dialkyl sulfosuccinate ester, sulfosuccinate alkyl di-salt, alkyl sulfoacetate, higher alcohol sulfate ester, A wet penetrant containing at least one selected from the group consisting of secondary higher alcohol ethoxy sulfate, fatty acid alkylol amide sulfate ester, polyoxyethylene distil phenyl ether, polyoxyethylene tristil phenyl ether,
The metal chelating agent contains 5% by weight (as solid content) of a methyl ethyl ester copolymer of acrylic acid and methacrylic acid as a soft binder, and di-2ethylhexyl sulfosuccinate sodium salt concentration of 0.1 as a wet penetrant. Pressurized water (pressure 650 kg / cm ² ) containing 5% by weight, sodium starch glycolate concentration 3% by weight and metal chelating agent concentration 3% by weight as a thickener was separated from a nozzle having a diameter of 1 mm by a distance of 20 cm at a flow rate of 35 liter / min After spraying on the asbestos-containing material at the position and peeling off the asbestos, the asbestos remains on the surface of the iron plate to which the asbestos was adhered, and a compound in which almost no asbestos can be seen,
A method for removing asbestos, which is a metal chelating agent containing at least one selected from the group consisting of a hydroxylaminocarboxylic acid derivative, thiourea, dithiocarbamate, thioglycolic acid or a derivative thereof . Pressurized water containing an agent containing the thickener according to claim 1, the soft binder according to claim 1, the wet penetrant according to claim 1, and the metal chelating agent according to claim 1 is supplied from a nozzle to asbestos. Asbestos removal method characterized by exfoliating and removing asbestos by injecting onto a processing object containing bismuth. A composition comprising a thickener according to claim 1, a soft binder according to claim 1, a wet penetrant according to claim 1, and a drug containing water and a metal chelating agent according to claim 1. After being applied to a processing object containing asbestos, the thickener according to claim 1, the soft binder according to claim 1, the wet penetrant according to claim 1, and the metal chelate according to claim 1. A method for removing asbestos, which comprises spraying pressurized water containing a chemical containing a chemical agent from a nozzle onto a processing object containing the asbestos to peel and remove asbestos. Thickener of claim 1 wherein a flexible binder of claim 1, wherein, wetting penetrant according to claim 1, and a pressurized water comprising a drug containing a metal chelating agent according to claim 1, wherein, the nozzle by jetting the processing target containing asbestos peeled off asbestos, to separate the water containing the collected asbestos was peeled dropped before Symbol pharmacists, mesh meshes than 1~100μm of stainless steel net A method for removing asbestos, comprising: filtering through a configured filter, then further filtering the filtrate through a polymer separation membrane having a pore size of 0.01 to 10 μm, and recycling the filtrate as water for pressurization. Thickener of claim 1 wherein a flexible binder of claim 1, wherein, wetting penetrant according to claim 1, and a pressurized water comprising a drug containing a metal chelating agent according to claim 1, wherein, the nozzle by jetting the processing target containing asbestos peeled off asbestos, to separate the water containing the collected asbestos was peeled dropped before Symbol pharmacists, mesh meshes than 1~100μm of stainless steel net Filtration through a configured filter, the filtrate is further filtered through a polymer separation membrane having a pore size of 0.01 to 10 μm, and filtered through the stainless steel mesh and asbestos residue filtered through the polymer separation membrane. The collected asbestos is melted or treated as specially controlled industrial waste, and the filtered microfiltrate is circulated and used as pressurized water. Asbestos removal method characterized in that it is treated as specially controlled industrial waste after having been absorbed into water and made solid. The water-absorbing agent is at least one selected from acrylic acid polymer partial alkali salt cross-linked products, acrylic acid / vinyl alcohol copolymer, starch and polyacrylic acid alkali salt cross-linked products, and carboxyalkyl cellulose alkali salt cross-linked products. The asbestos removal method of Claim 5 .

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