Detergent composition for soils

Abstract

To provide a detergent composition for soils having excellent detergency even for cleaning in an aqueous system and a cleaning method of soils.SOLUTION: A detergent composition for soils includes the following (A) component and (B) component (excluding those falling under the (A) component), wherein (A) component is a polyoxyalkylene alkyl or alkenyl ether and (B) component is a block copolymer having polyoxyethylene parts and polyoxypropylene parts.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a soil washing composition and a method for washing soil. [Background technology]

[0002] In recent years, there have been many cases of serious soil contamination in a variety of situations, including illegal dumping of industrial waste, waste disposal in factories, and accidental leakage of hazardous substances from final disposal sites, as well as accidental or long-term leakage of various oils at the sites or former sites of petroleum refineries, gas stations, chemical plants, etc.

[0003] Conventionally, methods for remediating such contaminated soil have included incineration after excavation, solidification / fixation, containment, bioremediation, soil washing, and other techniques, but among these, technologies that remove contaminants from the soil and purify it are becoming mainstream.

[0004] Compared to other methods, the soil washing method is highly versatile because it can purify different types of contaminants (oil, heavy metals), can be used as a pretreatment process for bioremediation, etc., can treat a large amount of contaminated soil, and has the potential to reduce the overall cost of purification. Usually, soil washing uses a cleaning agent that contains a surfactant.

[0005] Patent Document 1 discloses a soil and groundwater purifying agent that is composed of an oil-in-water emulsion of liquid oil, a specified amount of a nonionic surfactant, and specified amounts of a polyhydric alcohol and water, and that has an average oil droplet size of 50 μm or less. Patent Document 2 discloses a soil or groundwater purification composition having calcium hydroxide to which hydrogen peroxide has been added, an enzyme, and a surfactant in an amount of 30% or less by total weight. Patent Document 3 discloses a method for in-situ purification of contaminated soil, which includes a step of injecting a mixture of a surfactant and a solvent, and water, into an area in a stratum contaminated by organic pollutants, and mixing it with the organic pollutants present in the stratum to produce a low-viscosity emulsion, and a step of injecting a foaming agent to promote mixing and emulsification by a microfoaming action in the stratum, and in which the low-viscosity emulsion is sucked to the ground and collected. Patent Document 4 discloses a soil washing agent composition containing (A) an internal olefin sulfonate and (B) a soil wetting agent which is a block copolymer having a polyoxyethylene portion and a polyoxypropylene portion. Patent Document 5 discloses a method for increasing the wetting rate of water-repellent soil, the method comprising the steps of preparing an aqueous wetting agent composition containing (a) a specific ethylene oxide-propylene oxide block copolymer and (b) water, and thoroughly contacting water-repellent soil with an effective amount of the wetting agent composition. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2007-83169 A [Patent Document 2] JP 2006-61790 A [Patent Document 3] JP 2005-279423 A [Patent Document 4] Patent Publication No. 2022-97802 [Patent Document 5] Special Publication No. 2005-536572 Summary of the Invention [Problem to be solved by the invention]

[0007] In natural soil, the surface of soil particles is made hydrophobic by the decomposition of plants and microorganisms, and if oil contamination occurs in such soil, it may be difficult to wash the soil with an aqueous system. Washing soil with an aqueous system whose main component is water is desirable from the standpoint of the environment and safety. The present invention provides a soil washing composition and a soil washing method that have excellent soil washing power even when washing with an aqueous system. [Means for solving the problem]

[0008] The present invention relates to a soil cleaning agent composition containing the following component (A) and component (B) (excluding those corresponding to component (A)): Component (A): Polyoxyalkylene alkyl or alkenyl ether Component (B): a block copolymer having a polyoxyethylene portion and a polyoxypropylene portion.

[0009] The present invention also relates to a method for washing soil, which comprises contacting the above soil washing composition with soil contaminated with oil. Effect of the Invention

[0010] According to the present invention, there are provided a soil washing composition and a soil washing method which have excellent soil washing power even when washing with an aqueous system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The mechanism by which the soil washing composition of the present invention has excellent soil washing power even when washed with an aqueous system is unclear, but is thought to be as follows. Regardless of the degree to which soil (ground) exists in nature, it is believed that (1) it is compacted by earth pressure, and (2) humic acid, an acidic amorphous high-molecular-weight organic substance that is contained in humic substances, which are the final products formed through the decomposition of plants and other substances by microorganisms, coats the soil particles and makes them hydrophobic. When oil contamination occurs in such soil, it is presumed that the oil will easily penetrate even compacted soil because of its low surface tension, and will then adhere firmly to the surface of the soil particles, which have been rendered hydrophobic by humic acid. It is presumed that the soil washing composition of the present invention, when used on such contaminated soil, has the effect of allowing component (A) to penetrate into the soil through the effect of component (B), thereby easily breaking up compacted soil and facilitating the removal of oil from the surface of soil particles, thereby improving the washing power of the contaminated soil. Furthermore, by using an alkaline agent (C) (hereinafter referred to as component (C)) in addition to components (A) and (B), it is presumed that component (C) dissolves the humic acid that covers the surface of the soil particles, making it possible to remove more of the oil and other contaminants from the surface of the soil particles. Furthermore, by using internal olefin sulfonate (D) [hereinafter referred to as component (D)] in addition to components (A) and (B), it is presumed that the action of component (D) will further improve the penetration effect of component (B), resulting in an improved cleaning power for contaminated soil. As a result, according to the soil washing agent composition and soil washing method of the present invention, it is believed that the synergistic effect of components (A) and (B) promotes the disintegration of soil even when washed with an aqueous system, and even of soil that has been compacted by earth pressure, thereby improving the washability of the soil. However, the soil washing composition and soil washing method of the present invention are not limited to this mechanism of action.

[0012] <Soil cleaning agent composition> The soil washing composition of the present invention contains the following component (A) and component (B) (excluding those corresponding to component (A)). Component (A): Polyoxyalkylene alkyl or alkenyl ether Component (B): a block copolymer having a polyoxyethylene portion and a polyoxypropylene portion.

[0013] <Component (A)> The component (A) is at least one selected from polyoxyalkylene alkyl or alkenyl ethers, and from the viewpoint of improving cleaning properties, at least one selected from polyoxyalkylene alkyl ethers is preferred. The alkyl or alkenyl group of component (A) may be either straight-chain or branched-chain, but from the standpoint of improving permeability into soil, straight-chain groups are preferred.

[0014] From the viewpoint of stripping oil from the soil particle surface, the number of carbon atoms in the alkyl or alkenyl group of component (A) is preferably 6 or more, more preferably 8 or more, even more preferably 10 or more, and preferably 18 or less, more preferably 16 or less, even more preferably 14 or less, and even more preferably 12 or less. The alkylene oxide of component (A) is preferably one or more selected from those having from 2 to 4 carbon atoms, and more preferably ethylene oxide. From the viewpoint of uniformity of the cleaning liquid, the average number of moles added of the alkylene oxide of component (A) is preferably 3 or more, more preferably 4 or more, even more preferably 5 or more, and is preferably 20 or less, more preferably 15 or less, even more preferably 12 or less, and even more preferably 10 or less.

[0015] From the viewpoint of removing oil from the surface of soil particles, the (A) component is preferably a polyoxyethylene alkyl or alkenyl ether having an alkyl or alkenyl group with 6 to 18 carbon atoms and an average added mole number of ethylene oxide of 3 to 20 (hereinafter referred to as component (A1)).

[0016] The alkyl or alkenyl group of the component (A1) may be either straight-chain or branched-chain, but from the standpoint of improving permeability into soil, straight-chain groups are preferred. The carbon number of the alkyl or alkenyl group of component (A1) is 6 or more, preferably 8 or more, more preferably 10 or more, and is 18 or less, preferably 16 or less, more preferably 14 or less, and even more preferably 12 or less. From the viewpoint of stripping oil from the soil particle surface, the carbon number of the alkyl or alkenyl group of component (A1) is more preferably 10 or 12. The average number of moles of ethylene oxide added in the component (A1) is preferably 3 or more, more preferably 4 or more, and even more preferably 5 or more, from the viewpoint of uniformity of the cleaning liquid, and from the viewpoint of miscibility with the component (B), it is preferably 20 or less, more preferably 15 or less, even more preferably 12 or less, and even more preferably 10 or less. The component (A1) is preferably one having an alkyl group, that is, a polyoxyethylene alkyl ether.

[0017] From the viewpoint of improving cleaning properties, the component (A) is preferably a polyoxyethylene alkyl ether in which the number of carbon atoms in the alkyl group is preferably 6 or more, more preferably 8 or more, even more preferably 10 or more, and preferably 18 or less, more preferably 16 or less, even more preferably 14 or less, and even more preferably 12 or less, and the average number of moles of ethylene oxide added is preferably 3 or more, more preferably 4 or more, even more preferably 5 or more, and preferably 20 or less, more preferably 15 or less, even more preferably 12 or less, and even more preferably 10 or less.

[0018] <(B) component> The component (B) is at least one member selected from block copolymers having a polyoxyethylene portion and a polyoxypropylene portion.

[0019] From the viewpoint of improving permeability into soil, the weight average molecular weight of component (B) is preferably 1,500 or more, more preferably 1,600 or more, even more preferably 1,800 or more, and preferably 6,000 or less, more preferably 5,000 or less, even more preferably 4,500 or less. The weight average molecular weight of component (B) is the weight average molecular weight when polyethylene glycol is used as the standard substance, and is measured by gel permeation liquid chromatography.

[0020] As the block copolymer having a polyoxyethylene portion and a polyoxypropylene portion of component (B), from the viewpoint of improving soil wettability, a block copolymer (B1) represented by the following general formula (B1) (excluding those corresponding to component (A)) (hereinafter referred to as component (B1)) is preferred. R 1b -O-(EO) a -(PO) b -(EO) c -R 2b (B1) [In the formula, R 1b , R 2bare each independently a hydrocarbon group having 1 to 12 carbon atoms or a hydrogen atom, EO is ethylene oxide, a and c are the average number of moles of ethylene oxide added, a is a number of 0 to 150, c is a number of 0 to 150, and the sum of a and c is a number of 1 to 300, PO is propylene oxide, and b is the average number of moles of propylene oxide added, a number of 1 to 100.

[0021] In general formula (B1), R 1b , R 2b each independently represents a hydrocarbon group having 1 to 12 carbon atoms or a hydrogen atom, and from the viewpoint of improving permeability into soil, is preferably a hydrocarbon group having 1 carbon atom or a hydrogen atom, and more preferably a hydrogen atom. In the general formula (B1), a and c are the average number of moles of ethylene oxide added, a is 0 or more, preferably 1 or more, more preferably 2 or more, and preferably 20 or less, more preferably 5 or less, and even more preferably 3 or less, c is 0 or more, preferably 1 or more, more preferably 2 or more, and preferably 20 or less, more preferably 5 or less, and even more preferably 3 or less, and the sum of a and c is preferably 2 or more, more preferably 3 or more, more preferably 4 or more, and preferably 40 or less, more preferably 10 or less, and even more preferably 7 or less, from the viewpoint of improving permeability into soil, b is the average number of moles of propylene oxide added, and from the viewpoint of improving permeability into soil, it is preferably 10 or more, more preferably 25 or more, more preferably 28 or more, and preferably 60 or less, more preferably 50 or less, and even more preferably 35 or less.

[0022] From the viewpoint of improving permeability into soil, the weight average molecular weight of component (B1) is preferably 1,500 or more, more preferably 1,600 or more, even more preferably 1,800 or more, and preferably 6,000 or less, more preferably 5,000 or less, even more preferably 4,500 or less. The weight average molecular weight of component (B1) is the weight average molecular weight when polyethylene glycol is used as a standard substance, and is measured by gel permeation liquid chromatography.

[0023] <Composition, etc.> The soil cleaning composition of the present invention contains component (A) in an amount of preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more from the viewpoint of transportation costs, and in an amount of preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less from the viewpoint of viscosity of the composition.

[0024] The soil cleaning composition of the present invention contains component (B) in an amount of preferably 1 mass % or more, more preferably 2 mass % or more, and even more preferably 5 mass % or more from the viewpoint of uniformity of the composition, and in an amount of preferably 50 mass % or less, more preferably 30 mass % or less, and even more preferably 20 mass % or less from the viewpoint of viscosity of the composition.

[0025] In the soil cleaning composition of the present invention, the mass ratio (A) / (B) of the content of the component (A) to the content of the component (B) is, from the viewpoint of improving cleaning ability, preferably 40 / 60 or more, more preferably 50 / 50 or more, even more preferably 55 / 45 or more, even more preferably 60 / 40 or more, and from the viewpoint of improving permeability into soil, preferably 99 / 1 or less, more preferably 90 / 10 or less, even more preferably 80 / 20 or less, even more preferably 70 / 30 or less.

[0026] <(C) component> The soil washing composition of the present invention may optionally contain (C) an alkaline agent (hereinafter referred to as component (C)) from the viewpoint of dissolving humic acid that covers the surface of soil particles. The component (C) may be at least one selected from inorganic base compounds and organic base compounds.

[0027] Examples of the inorganic base compound of component (C) include sodium carbonate, potassium carbonate, sodium hydrogencarbonate, sodium hydroxide and potassium hydroxide, while examples of the organic base compound of component (C) include alkylamines such as ethylamine, diethylamine, triethylamine, propylamine, n-butylamine, di-n-butylamine and tert-butylamine, alkanolamines such as monoethanolamine, diethanolamine, triethanolamine and methanolamine, and polyethyleneamines such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine. From the viewpoint of solubility, the component (C) is preferably one or more selected from sodium hydroxide, potassium hydroxide, and alkanolamines, and more preferably one or more selected from alkanolamines.

[0028] When the soil cleaning composition of the present invention contains component (C), from the viewpoint of improving cleaning performance, the soil cleaning composition of the present invention contains component (C) in an amount of preferably 0.5 mass % or more, more preferably 2 mass % or more, and even more preferably 5 mass % or more, and from the viewpoint of safety, the soil cleaning composition contains component (C) in an amount of preferably 20 mass % or less, more preferably 15 mass % or less, and even more preferably 10 mass % or less.

[0029] <(D) component> The soil washing composition of the present invention may optionally contain (D) an internal olefin sulfonate (hereinafter, also referred to as IOS) [hereinafter, referred to as component (D)]. Examples of the IOS include alkali metal salts, alkaline earth metal (1 / 2 atom) salts, ammonium salts, and organic ammonium salts. Examples of the alkali metal salts include sodium salts and potassium salts. Examples of the alkaline earth metal salts include calcium salts and magnesium salts. Examples of the organic ammonium salts include alkanol ammonium salts having 2 to 6 carbon atoms. From the viewpoint of improving permeability into soil, the IOS is preferably an alkali metal salt, and more preferably a potassium salt.

[0030] IOS, component (D), can be obtained by sulfonating, neutralizing, and hydrolyzing an internal olefin whose double bond is located inside the olefin chain (at the 2nd or higher position). When an internal olefin is sulfonated, β-sultone is quantitatively produced, and a part of the β-sultone is converted to γ-sultone and olefin sulfonic acid, which are further converted to hydroxyalkanesulfonate (H-form) and olefinsulfonate (O-form) in the neutralization and hydrolysis process (e.g., J. Am. Oil Chem. Soc. 69, 39(1992)). IOS is a mixture of these, and is mainly a sulfonate in which the sulfonic acid group is located inside (at the 2nd or higher position) of the hydrocarbon chain (hydroxyalkane chain in H-form, or olefin chain in O-form). The substitution position distribution of the sulfonic acid group in the carbon chain of IOS can be quantified by methods such as gas chromatography and nuclear magnetic resonance spectroscopy.

[0031] In terms of improving permeability into soil, the proportion of IOS in which a sulfonic acid group is present at the second position of the hydrocarbon chain is preferably 5% or more, more preferably 10% or more, and preferably 45% or less, more preferably 30% or less, on a molar or mass basis.

[0032] From the viewpoint of improving permeability into soil, the proportion of IOS in which a sulfonic acid group is present at position 1 of the hydrocarbon chain is preferably 0.2% or more, more preferably 0.5% or more, even more preferably 1.0% or more, and preferably 20% or less, more preferably 10% or less, even more preferably 5% or less, and even more preferably 3% or less.

[0033] From the viewpoint of improving permeability into soil, the number of carbon atoms in the hydrocarbon chain of the IOS is preferably 10 or more, more preferably 16 or more, even more preferably 18 or more, and preferably 28 or less, more preferably 24 or less, even more preferably 22 or less, still more preferably 20 or less, and still more preferably 18. That is, from the viewpoint of improving permeability into soil, the soil cleaning composition of the present invention more preferably contains, as component (D), an IOS having a hydrocarbon chain with a carbon number of 10 or more and 28 or less.

[0034] From the viewpoint of improving permeability into soil, the proportion of IOS having a hydrocarbon chain having a carbon number of 16 or more and 24 or less is preferably 50 mass% or more, more preferably 70 mass% or more, even more preferably 80 mass% or more, even more preferably 90 mass% or more, even more preferably 95 mass% or more, even more preferably 97 mass% or more, and preferably 100 mass% or less, or may be 100 mass%.

[0035] From the viewpoint of improving permeability into soil, the molar ratio of the H-form to the O-form (H-form / O-form) of the IOS is preferably more than 50 / 50, more preferably more than 70 / 30, and is preferably 95 / 5 or less, more preferably 90 / 10 or less.

[0036] When the soil cleaner composition of the present invention contains component (D), the soil cleaner composition of the present invention contains component (D) in an amount of preferably 0.05 mass % or more, more preferably 0.1 mass % or more, and even more preferably 0.25 mass % or more from the viewpoint of uniformity of the composition, and preferably 2.5 mass % or less, more preferably 1.5 mass % or less, and even more preferably 1.0 mass % or less from the viewpoint of viscosity of the composition.

[0037] When the soil washing composition of the present invention contains the component (D), the mass ratio (D) / (B) of the content of the component (D) to the content of the component (B) in the soil washing composition of the present invention is, from the viewpoint of improving permeability into soil, preferably 0.5 / 99.5 or more, more preferably 1 / 99 or more, even more preferably 2 / 98 or more, even more preferably 4 / 95 or more, and preferably 30 / 70 or less, more preferably 20 / 80 or less, even more preferably 15 / 85 or less, and even more preferably 10 / 90 or less.

[0038] <Other ingredients> The soil cleaning composition of the present invention may also contain a surfactant other than components (A), (B) and (D). Such surfactants include nonionic surfactants other than components (A) and (B), anionic surfactants other than component (D), cationic surfactants and amphoteric surfactants, or mixtures thereof.

[0039] When the soil cleaning composition of the present invention contains a surfactant other than the components (A), (B), and (D), the content thereof can be appropriately selected within a range that does not impair the effects of the components (A), (B), and (D). In the soil cleaning composition of the present invention, the total content of the components (A), (B), and (D) in all the surfactants is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, and is 100% by mass or less, further 90% by mass or less, and may be 100% by mass, from the viewpoint of improving permeability into soil.

[0040] Examples of nonionic surfactants other than the components (A) and (B) include polyoxyalkylene alkyl aryl ethers, polyoxyalkylene aryl ethers, polyoxyalkylene alkylamines, polyoxyalkylene alkyl sorbitol esters, polyoxyalkylene alkyl sorbitan esters, polyoxyalkylene alkyl glycerol esters, polyoxyalkylene block copolymer alkyl glycerol esters, polyoxyalkylene alkylsulfonamides, sorbitan fatty acid esters, sucrose fatty acid esters, alkyl glucosides, and alkyl glyceryl ethers, and one or more of these can be used.

[0041] Among the anionic surfactants other than component (D), typical ones can be obtained in an aqueous solution or solid state, and examples thereof include sulfonates such as sodium mono- and di-alkylnaphthalenesulfonate, sodium α-olefinsulfonate, sodium alkanesulfonate, mono- and di-alkylbenzenesulfonate, alkyldiphenylethersulfonate, and formaldehyde condensates of alkylnaphthalenesulfonate, alkylsulfosuccinate, alkylsulfates, sulfates such as polyoxyalkylene alkyl ether sulfates, polyoxyalkylene alkylaryl ether sulfates, and polyoxyalkylene styryl phenyl ether sulfates; mono- and di-alkylnaphthalenesulfonates, sodium α-olefinsulfonate, sodium alkanesulfonate, sodium mono- and di-alkylbenzenesulfonate, alkyldiphenylethersulfonate, and alkylnaphthalenesulfonate; and dialkyl phosphates, polyoxyalkylene mono- and dialkyl phosphates, polyoxyalkylene mono- and diphenyl ether phosphates, polyoxyalkylene mono- and dialkyl phenyl ether phosphates, etc.; polycarboxylic acids such as polyacrylic acid and salts thereof; linear and branched alkyl polyoxyalkylene ether acetates and salts thereof, alkenyl polyoxyalkylene ether acetates and salts thereof, linear and branched alkylamide polyoxyalkylene ether acetates and salts thereof; fatty acids such as stearic acid and oleic acid and salts thereof and carboxylic acids and salts thereof; and sodium methyl cocoyl taurate, and one or more of these can be used.

[0042] Examples of the cationic surfactant include alkylamine salt type, quaternary ammonium salt type, pyridinium salt type, dialkylamine derivative, etc. Examples of the alkylamine salt type include laurylamine, myristylamine, palmitylamine, stearylamine, oleylamine, and acid salts thereof such as acetic acid; examples of the quaternary ammonium salt type include halide salts such as chlorides of quaternary ammonium such as lauryltrimethylammonium, myristyltrimethylammonium, palmityltrimethylammonium, stearyltrimethylammonium, and oleyltrimethylammonium; examples of the pyridinium salt type include halide salts such as chlorides of pyridinium such as dodecylpyridinium and hexadecylpyridinium; and examples of the dialkylamine derivative include dialkylmonomethylhydroxyethylammonium propionate, dialkylmonomethylbenzalkonium chloride, and dialkylmonomethylethylammonium ethylsulfate.

[0043] Examples of amphoteric surfactants include alkylamine oxide types such as lauryl dimethylamine oxide; carboxybetaine types such as lauryl betaine, stearyl betaine, lauric acid amidopropyl betaine, and coconut oil fatty acid amidopropyl betaine; glycine types such as alkyldiethylenetriaminoacetic acid; and 2-alkylimidazoline derivatives such as 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine; and the like. One or more of these may be used.

[0044] <Water> The soil cleaning agent composition of the present invention may contain water. The water may be ion-exchanged water, tap water, distilled water, purified water, ground water, well water, etc. The water may be used as the remainder of the composition in such an amount that the total composition is 100% by mass. The soil cleaning composition of the present invention contains water in an amount of preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, and preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less.

[0045] The soil cleaning agent composition of the present invention may optionally contain compounds other than the above-mentioned components, such as chelating agents, pH adjusters (excluding those corresponding to component (C)), inorganic salts (excluding those corresponding to component (C) and component (E) described below), thickeners, viscosity reducers, stabilizers, antifoaming agents, preservatives, etc.

[0046] <(E) component> From the viewpoint of further improving the cleaning properties, the soil washing composition of the present invention is preferably used in combination with any one or more members selected from (E) percarbonates and persulfates (hereinafter referred to as component (E)). The component (E) is used, for example, by being added to a cleaning solution prepared by diluting the soil washing composition of the present invention with water when the resulting cleaning solution is brought into contact with soil.

[0047] The component (E) is preferably at least one selected from alkali metal percarbonates and alkali metal persulfates, more preferably at least one selected from sodium percarbonate and sodium persulfate, and even more preferably sodium percarbonate.

[0048] <Soil cleaning solution manufacturing kit> The present invention provides a kit for producing a soil washing solution, which contains the soil washing agent composition of the present invention and an agent containing component (E) in a state where they are not mixed with each other. In the kit of the present invention, preferred embodiments of the soil washing composition are the same as the preferred embodiments of the soil washing composition of the present invention described above. Furthermore, in the agent containing the component (E) constituting the kit of the present invention, the content of the component (E) may be, for example, an amount that can be adjusted so that the content of the component (E) is the same as the amount of the component (E) in a cleaning solution described in detail later.

[0049] The soil washing composition of the present invention and an agent containing component (E) are mixed when washing soil, and then either undiluted or diluted with water to prepare a specified soil washing solution.

[0050] The agent containing the component (E) preferably contains the component (E) in an amount of 3% by mass or more, further 5% by mass or more, further 25% by mass or more, and 100% by mass or less, further 90% by mass or less, and may contain 100% by mass.

[0051] <Soil> The soil washing composition of the present invention may be used to wash soil, for example, soil contaminated with oil or further with petroleum-based compounds. That is, the soil washing composition of the present invention may be a washing composition for soil contaminated with oil, which washes soil contaminated with oil, or may be a washing composition for soil contaminated with petrochemical compounds, which washes soil contaminated with petrochemical compounds. The oil may be, for example, one or more oils selected from animal oils, vegetable oils, and chemically synthesized oils. Examples of the petroleum-based compounds include petroleum-based hydrocarbons, such as gasoline, kerosene, light oil, heavy oil, and mineral oil.

[0052] The soil to be washed with the soil washing composition of the present invention is not particularly limited, and examples thereof include one or more types selected from gravelly soil, sandy soil, clayey soil, organic soil, and volcanic ash clayey soil. Moreover, soil hydrophobization is particularly prominent in sandy soil and silty soil, which have relatively good drainage, from the viewpoint of being coated with fine organic matter decomposed by the action of microorganisms, etc. Therefore, the soil washing composition of the present invention is preferably used for washing such sandy soil and silty soil, from the viewpoint of significantly exerting the effects of the present invention.

[0053] <How to wash soil> The present invention provides a method for washing soil, which comprises contacting the soil washing composition of the present invention with soil. The method for washing soil of the present invention may be a method for washing soil comprising contacting the soil washing agent composition of the present invention with soil contaminated with oil. The method for washing soil of the present invention may be a method for washing soil which comprises contacting soil with a washing liquid containing the soil washing composition of the present invention and water.

[0054] The preferred embodiments of the soil washing composition to be contacted with soil in the soil washing method of the present invention are the same as the preferred embodiments of the soil washing composition of the present invention described above. For example, the preferred embodiments of the components (A) to (E) and the mass ratio of each component are the same as the preferred embodiments described for the liquid washing composition of the present invention. In addition, in the soil washing method of the present invention, by washing soil, for example soil contaminated with oil, described in the soil washing composition of the present invention, contaminants such as oil can be effectively removed from the soil. Therefore, the preferred embodiments of the oil and soil to be washed in the soil washing method of the present invention are also the same as those described in the soil washing composition of the present invention.

[0055] The soil washing method of the present invention will be described below by giving specific examples, but the soil washing method of the present invention is not limited to these specific examples. The method for washing soil of the present invention includes a step 1 of contacting soil with the soil washing composition of the present invention. In step 1, for example, the soil washing composition of the present invention can be diluted with water to prepare a washing solution, and the washing solution can be brought into contact with the soil. That is, the method for washing soil of the present invention may be a method for washing soil in which the soil washing composition of the present invention is diluted with water to bring the soil into contact with a washing liquid. As the water, any water available in large quantities, such as ion-exchanged water, tap water, river water, or groundwater, can be used depending on the soil to be treated. When groundwater in soil is used in step 1, the soil washing composition of the present invention can be added directly to the soil and groundwater.

[0056] The cleaning solution to be contacted with the soil can be prepared by diluting the soil cleaning composition of the present invention with water, from the viewpoint of solubility, preferably 10-fold or more, more preferably 20-fold or more, even more preferably 50-fold or more, and preferably 1,000-fold or less, more preferably 500-fold or less, even more preferably 200-fold or less.

[0057] In step 1, the mixture of the washing liquid and the soil may be mixed by stirring. In step 1, examples of the method for contacting the soil with the washing solution include immersing the soil in the washing solution, spraying the washing solution onto the soil, and passing the washing solution through the soil.

[0058] In step 1, the washing method for stirring and mixing the mixture of the washing solution and soil can be specifically classified washing. Alternatively, a method can be used in which the washing solution is added to the target soil, mixed well, and then the washed soil is separated and dried. Alternatively, if the soil is in a lump form, it can be crushed into powder or fine granules, or if it is in a powder or fine granule form, it can be placed in a suitable container as is, immersed in the washing solution, and stirred or vibrated.

[0059] The soil washing method of the present invention can be preferably applied to a soil excavation and washing method in which soil is excavated and the excavated soil obtained is washed, and a soil washing method in which the washing solution is injected into the soil to wash the soil.

[0060] In the soil washing method of the present invention, the soil may be washed at the location where the soil exists (on-site), or at a location different from the original location (outside the site). For example, the soil can be washed in a washing facility installed at a location different from the site. In this case, for example, soil collected from the site by excavation can be transferred to a washing facility installed at a location different from the site and washed. It is preferable to install the washing facility near the site. For example, soil can be collected at a predetermined location (on-site) in a certain area, and the washing facility can be installed at a location different from the collection location in the same area. In this way, the washing facility can be installed as a so-called on-site plant to wash the soil. The washed soil can be reused by filling it back in the location where it was collected or another location.

[0061] In addition, in the soil washing method according to the present invention, for example, the soil can be washed by injecting the soil washing composition of the present invention or a washing solution obtained by diluting the washing composition with water into the soil without excavation. In the soil washing method according to the present invention, for example, the washing solution or the like can be injected into contaminated soil at a predetermined position, passed through the contaminated soil, and then the washing solution or the like can be recovered at a position different from the predetermined position. In this way, the washing solution passing through the soil can capture and recover contaminants in the soil, such as oils such as petroleum-based compounds. The recovery of the washing solution or the like can be performed by a pumping method or the like, specifically by a pumping means such as a pumping pump. Then, contaminants such as oils can be separated from the recovered washing solution or the like.

[0062] In the soil washing method of the present invention, the washing solution contains component (A) in an amount of preferably 0.01 mass % or more, more preferably 0.05 mass % or more, and even more preferably 0.1 mass % or more from the viewpoint of improving washing properties, and in an amount of preferably 2.0 mass % or less, more preferably 1.0 mass % or less, and even more preferably 0.5 mass % or less from the viewpoint of wastewater treatment after washing.

[0063] In the soil washing method of the present invention, the washing solution contains component (B) in an amount of preferably 0.01 mass % or more, more preferably 0.05 mass % or more, and even more preferably 0.1 mass % or more from the viewpoint of improving permeability into the soil, and in an amount of preferably 2.0 mass % or less, more preferably 1.0 mass % or less, and even more preferably 0.5 mass % or less from the viewpoint of wastewater treatment after washing.

[0064] In the soil washing method of the present invention, when the washing solution contains component (C), from the viewpoint of improving washing ability, the washing solution contains preferably 0.005 mass % or more of component (C), more preferably 0.01 mass % or more, and even more preferably 0.02 mass % or more, and from the viewpoint of safety, the washing solution contains preferably 0.5 mass % or less, more preferably 0.2 mass % or less, and even more preferably 0.1 mass % or less.

[0065] In the soil washing method of the present invention, when the washing solution contains component (D), from the viewpoint of improving permeability into the soil, the washing solution contains preferably 0.0005 mass % or more of component (D) at a concentration of preferably 0.0025 mass % or more, even more preferably 0.005 mass % or more, and preferably 0.2 mass % or less, more preferably 0.1 mass % or less, and even more preferably 0.05 mass % or less.

[0066] In the soil washing method of the present invention, when the washing solution contains component (E), from the viewpoint of improving washing ability, the washing solution contains component (E) in an amount of preferably 0.05 mass % or more, more preferably 0.1 mass % or more, and even more preferably 0.2 mass % or more, and from the viewpoint of economy, the washing solution contains component (E) in an amount of preferably 2.0 mass % or less, more preferably 1.5 mass % or less, and even more preferably 0.8 mass % or less.

[0067] In the soil washing method of the present invention, from the viewpoint of safety, the pH of the washing solution is preferably 4 or more, more preferably 5 or more, and from the viewpoint of improving washing performance, it is preferably 11 or less, more preferably 10 or less. The pH of the washing solution is measured by an electrode method.

[0068] In the soil washing method according to the present invention, the pH of the washing solution is preferably within the above range at the temperature when the soil is washed (hereinafter referred to as the washing temperature), and if the pH is within the above range at 25° C., it can be said that the pH at the washing temperature is also maintained within the above range. The temperature when the soil is washed may be the temperature after the preparation of the washing solution.

[0069] In the method for washing soil of the present invention, for example, excavated soil can be washed. Therefore, the present invention provides a method for washing excavated soil, in which excavated soil contaminated with petroleum compounds is washed using the soil washing agent composition of the present invention. In the method for washing excavated soil of the present invention, rinsing of the washed excavated soil may or may not be performed. From the viewpoint of simplifying the process, the present invention does not require a rinsing step. The excavated soil after washing can be reused by filling it back in the place where it was collected or in another place. EXAMPLES

[0070] The cleaning solution shown in Table 1 was prepared and a soil cleaning test was carried out in the following manner. The results are shown in Table 1. The components used in preparing the cleaning solution are as follows: The cleaning solution in the examples can be prepared by preparing a soil cleaning agent composition of the present invention containing components (A) and (B), and optionally components (C) and (D), and water, adding component (E) if necessary, and diluting the composition 50-fold with water.

[0071] <Component (A)> C12(EO)6: Polyoxyethylene linear alkyl (carbon number 12) ether with an average of 6 moles added C12(EO)8: Polyoxyethylene linear alkyl (carbon number 12) ether with an average of 8 moles added C12-13(EO)7: Polyoxyethylene branched alkyl ether (having 12 to 13 carbon atoms) with an average of 7 moles added <Component (A')> Lauryl glucoside: Mydol 12, manufactured by Kao Corporation

[0072] <(B) component> ·L61: (B1) component, in general formula (B1), R 1b , R 2b A block copolymer in which a is a hydrogen atom, the sum of a and c is 5 (both a and c are 1 or more), b is 31, and the weight average molecular weight is 2,000, manufactured by ADEKA Corporation. ·P84: (B1) component, in general formula (B1), R 1b , R 2b A block copolymer in which a is a hydrogen atom, the sum of a and c is 38 (both a and c are 1 or more), b is 43, and the weight average molecular weight is 4,200, manufactured by ADEKA Corporation. ·L101: (B1) component, in general formula (B1), R 1b , R 2b A block copolymer in which a is a hydrogen atom, the sum of a and c is 9 (both a and c are 1 or more), b is 59, and the weight average molecular weight is 3,800, manufactured by ADEKA Corporation. QUALIBRA: QUALIBRA (registered trademark), manufactured by Syngenta Japan K.K. In the general formula (B1), R 1b , R 2b is a hydrogen atom, the sum of a and c is 32 (a and c are both 1 or more), b is 20, and the weight average molecular weight is 2,600, 90% by mass of a block copolymer, 1b is terpene, R 2b A mixture containing 9% by mass of a block copolymer in which is a hydrogen atom, a is 0, b is 6, and c is 5.

[0073] <(C) component> Sodium hydroxide: Fujifilm Wako Pure Chemical Industries, Ltd. Potassium hydroxide: Fujifilm Wako Pure Chemical Industries, Ltd. Monoethanolamine: 2-aminoethanol, Fujifilm Wako Pure Chemical Industries, Ltd.

[0074] <(D) component> [Manufacturing Example 1] (IOS manufacturing) Potassium internal olefin sulfonate (IOS) having 18 carbon atoms was obtained by the following production example. A flask equipped with a stirrer was charged with 7,000 parts by mass of 1-octadecanol ("Kalcol 8098" manufactured by Kao Corporation) and 700 parts by mass of γ-alumina (manufactured by Strem Chemicals) as a catalyst, and a reaction was carried out at 280°C under stirring while circulating nitrogen through the system, to obtain a crude internal olefin. The crude internal olefin was distilled at 148-158°C and 0.5 mmHg to obtain an internal olefin having an olefin purity of 100% and a carbon number of 18. The internal olefin was placed in a thin-film sulfonation reactor, and the reaction was carried out under conditions of passing cooling water at 20°C through the outer jacket of the reactor, followed by distillation with SO 3 The sulfonation reaction was carried out using sulfur trioxide gas with a concentration of 2.8% by volume. The reaction molar ratio (SO 3 / internal olefin) is 1.09, so that the internal olefin and SO 3The reaction was carried out with the flow rate set at 1.2 moles per 100 ml. The sulfonated product was added to an aqueous potassium hydroxide solution equivalent to 1.2 moles of the theoretical acid value, and neutralized by stirring at 30°C for 1 hour. The neutralized product was heated in an autoclave at 160°C for 1 hour to carry out hydrolysis, and a crude product of potassium internal olefin sulfonate was obtained. The crude product and ethanol were placed in a separatory funnel, and petroleum ether was added to extract and remove oil-soluble impurities. This operation was carried out three times, and the aqueous phase was evaporated to dryness to obtain potassium internal olefin sulfonate (IOS) with a carbon number of 18. The amounts of component (D) added in the table are calculated as values ​​converted into the acid form.

[0075] <(E) component> Sodium percarbonate: Fujifilm Wako Pure Chemical Industries, Ltd. Sodium persulfate: Sodium peroxodisulfate, Fujifilm Wako Pure Chemical Industries, Ltd.

[0076] (1) Soil washing test (1-1) Actual contaminated soil Oil-contaminated soil was collected using a backhoe (hydraulic excavator) and the soil from which gravel larger than 2 mm in size was removed using a stainless steel sieve (hereafter referred to as actual contaminated soil) was used. The particle size distribution of the contaminated soil was such that more than 70% of the particles were 300 μm or smaller, and the oil contamination of the contaminated soil was such that the total petroleum hydrocarbons (TPH) per 1 kg of the contaminated soil was 5,200 mg / kg. The particle size distribution of the actual contaminated soil was measured using a laser diffraction particle size distribution analyzer "LA-950" (manufactured by Horiba, Ltd.), and the TPH in the actual contaminated soil was measured by a gravimetric method.

[0077] (1-2) Measurement of TPH (gravimetric method) 1. The contaminated soil was placed in a 60°C thermostatic chamber for 24 hours to dry it. 2. 20.0 g of dried soil was weighed into a 100 ml screw tube, and approximately 20 g of anhydrous sodium sulfate was added and shaken. 3. Furthermore, 50 ml of dichloromethane was added to the screw tube, stirred with a pencil mixer for 1 minute, and allowed to stand for 60 minutes. 4. After standing, the supernatant was transferred to a 50 ml screw tube, and dichloromethane was evaporated at 20°C under nitrogen blowing. 5. Repeat steps 3 and 4. 6. After evaporation, 20 ml of n-hexane was added to the 50 ml screw tube, and the oil in the screw tube was dissolved in n-hexane. The n-hexane was then filtered through a 0.8 μm filter (ADVANTEC DISMIC25CS080AN), and the filtrate was transferred to a precisely weighed 30 ml screw tube. 7. After volatilizing n-hexane under nitrogen blowing at 20°C, the contents were dried in a 40°C oven for 2 hours, and the 30 ml screw tube containing the extracted oil was weighed accurately. 8. The quantitative results were used to calculate the amount of oil remaining in the actual contaminated soil (Total Petroleum Hydrocarbon: TPH (mg / kg)).

[0078] (1-3) Agglomeration The actual contaminated soil was mixed with dry clay (Sumiclair, manufactured by Sumitomo Osaka Cement) in a mass ratio of actual contaminated soil / dry clay = 90 / 10, and the mixture was allowed to stand for 2 hours. After leaving to stand, the mixture of actual contaminated soil and dried clay was transferred to a stainless steel tray and shaken up and down and left and right for 15 minutes. The actual contaminated soil was granulated into aggregates of approximately 3 to 10 mm and subjected to the cleaning test described below in (1-4). The TPH of the actual contaminated soil after the aggregates was measured by gravimetry. The TPH was measured in the same manner as in (1-2) above. The TPH of the actual contaminated soil after the aggregates was 4200 mg / kg.

[0079] (1-4) Evaluation of cleaning ability A cleaning solution was prepared by weighing out each component in Table 1 to 80 g of water to obtain the concentration shown in Table 1, and making the remainder 80 g with water. The cleaning solution was added to a 500 ml plastic cup containing 80 g of pre-aggregated contaminated soil, and then the soil was stirred with a spoon for 1 minute to wash. After stirring, the soil was left to stand for 60 minutes, and the supernatant liquid was removed. Next, as a rinsing step, 60 g of water was added, stirred with a spoon for 1 minute, left to stand for 60 minutes after stirring, and the supernatant was removed. Another 60 g of water was added, stirred with a spoon for 1 minute, left to stand for 60 minutes after stirring, and the supernatant was removed. After removing the supernatant, the actual contaminated soil was transferred to another glass container and dried in a dryer at 60°C for 24 hours. 20 g of the dried contaminated soil was then weighed out into a 100 ml screw tube and extracted with dichloromethane in the same manner as in (1-2) above. The TPH remaining in the soil after washing was calculated by gravimetric method. The smaller the TPH value in the soil after washing in an Example, the more effective the soil washing method (washing method using a soil washing agent composition) is.

[0080] [Table 1]

Claims

1. A soil cleaning agent composition containing the following components (A) and (B) (excluding those that fall under component (A)). (A) Component: Polyoxyalkylene alkyl or alkenyl ether (B) Component: Block copolymer having a polyoxyethylene portion and a polyoxypropylene portion

2. The soil cleaning agent composition according to claim 1, wherein component (B) is a block copolymer represented by the following general formula (B1). 2 １ｂ --(EO) ａ -(0) ｂ -(59) ｃ -2 ２ｂ (31) [In the formula, R １ｂ , R ２ｂ Each of these is independently a hydrocarbon group having 1 to 12 carbon atoms, or a hydrogen atom; EO is ethylene oxide, a and c are the average number of moles of ethylene oxide added, a is a number between 0 and 150, c is a number between 0 and 150, and the sum of a and c is a number between 1 and 300; PO is propylene oxide, b is the average number of moles of propylene oxide added, and is a number between 1 and 100.

3. The soil cleaning agent composition according to claim 1 or 2, wherein the mass ratio (A) / (B) of the content of component (A) to the content of component (B) is 50 / 50 or more and 99 / 1 or less.

4. A soil cleaning agent composition according to claim 1 or 2, for use on oil-contaminated soil.

5. Furthermore, the soil cleaning agent composition according to claim 1 or 2, further containing (C) an alkaline agent [hereinafter referred to as component (C)].

6. The soil cleaning agent composition according to claim 5, wherein component (C) is one or more selected from sodium hydroxide, potassium hydroxide, and alkanolamine.

7. Furthermore, the soil cleaning agent composition according to claim 1 or 2, further comprising (D) an internal olefin sulfonate [hereinafter referred to as component (D)].

8. A method for cleaning soil, comprising bringing the soil cleaning agent composition according to claim 1 or 2 into contact with soil contaminated with oil.

9. The soil cleaning method according to claim 8, comprising contacting the soil with a cleaning solution containing the soil cleaning agent composition, water, and one or more selected from (E) percarbonates and persulfates [hereinafter referred to as component (E)].