JPH11323332A - Conditioner for water-containing soil and conditioning process - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conditioner suitable for conditioning and recycling water- containing soil, and a conditioning process. SOLUTION: A conditioner for water-containing soil comprises a water-soluble polymer obtained by polymerizing a monomer component containing at least one monomer chosen from the group consisting of monomers of general formula I (wherein R1 is H or a methyl group; and R2 is H, a methyl group or an ethyl group) and a monomer of general formula II (wherein R3 is H or a methyl group; X is a -COO- group or -CH2 O group; k is 2 or 3; n is an integer of from 0 to 100; and R4 is H, an 1-12C alkyl group, a phenyl group, a phenyl group having an 1-12C alkyl group or a benzyl group). In a conditioning process for water-containing soil, water-containing soil and the conditioner comprising the water-soluble polymer are mixed to condition the water-containing soil into a solid matter having a sufficient strength and a predetermined particle size which is granulated in a particulate form.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an agent for improving water-containing soil and a method for improving water-containing soil, and more particularly, to a method suitable for reusing sand as a substitute. The present invention relates to an improving agent and an improving method for improving a hydrated soil into granules.

[0002]

2. Description of the Related Art Generally, for example, in the treatment of construction waste material resulting from excavation work using a cast-in-place pile method, a mud shield method, or the like, excavated soil generated during excavation is supplied by supplying excavated mud to an excavation hole. Is discharged to the outside together with the drilling mud.

[0003] The above-mentioned generated soil is not classified as industrial waste specified in the Waste Disposal and Waste Management Law, because earth and sand are separated and reused for cutting at construction sites. However, excavated muddy water, which has a muddy state, more specifically, a slurry containing a large amount of water together with clay, and exhibits fluidity, cannot be piled up on a standard specification dump truck, and for example, a person can walk on it. Has no state. Therefore, the above drilling mud is
It cannot be used as backfill material as it is, but must be treated as industrial waste in accordance with the Waste Management Law. For this reason, the above-mentioned excavated mud is subjected to dewatering press or the like to carry out solid-liquid separation so that it can be transported or the like. Coalescence and the like are mixed and solidified (improved). The hydrous soil improved by these improvement methods is discarded at a predetermined disposal site such as a landfill disposal site, or the improved hydrous soil is used in civil engineering work in which excavation holes need to be backfilled. Is injected into a wellbore.

[0004] As such an improved method, for example, Japanese Patent Application Laid-Open No. 1-176499 discloses a method of mixing a water-soluble synthetic polymer substance or the like with water-containing soil.

[0005]

However, since water-containing soil must be treated as industrial waste, it requires a great deal of disposal costs. In addition, the final disposal amount of hydrous soil as construction waste material is enormous, and landfill disposal of hydrous soil is difficult every day due to difficulties in obtaining land for final disposal sites to dispose of hydrous soil and opposition from local residents. Has become. Therefore, when the hydrous soil is treated by the above-mentioned conventional improvement method, there is also a problem that it is difficult to secure land for a final disposal site such as a disposal site. For this reason, there is a long-felt need for an improved method capable of reusing water-containing soil.

[0006] For example, Japanese Patent Application Laid-Open No. 4-34585 discloses a soil-improving agent comprising a water-soluble polymer having a carboxyl group and lime. However, since the water-soluble polymer has a carboxyl group, the performance of the improver is easily affected by ions contained in hydrous soil. Therefore, when a dewatering press is used to obtain a dewatered cake, for example, when a coagulant or the like is used, the performance of the improver is affected by the coagulant, and when sufficient performance cannot be exhibited, It may be necessary to use a large amount of an improving agent for the dewatered cake. Therefore, there is a need for an improver whose performance is hardly affected by ions contained in hydrous soil.

[0007] The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide an improving agent and an improving method suitable for improving and reusing water-containing soil. is there.

[0008]

Means for Solving the Problems The present inventors have diligently studied an improving agent and a method for improving a hydrous soil in order to achieve the above object. As a result, by mixing a modifier containing a water-soluble polymer obtained by polymerizing a monomer component containing a monomer having a specific molecular structure into the hydrous soil, the hydrous soil is solidified, and industrial waste is discharged. They have found that they can be reused without discarding them as objects, and have completed the present invention.

That is, the improver for hydrous soil according to the first aspect of the present invention has the general formula (1)

[0010]

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Wherein R ₁ represents a hydrogen atom or a methyl group, and R ₂ represents a hydrogen atom, a methyl group or an ethyl group, and a monomer represented by the general formula (2):

[0012]

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(Wherein, R ₃ represents a hydrogen atom or a methyl group, X represents a —COO— group or a —CH ₂ O— group,
k is 2 or 3; n is an integer from 0 to 100;
₄ represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a phenyl group, a phenyl group having an alkyl group having 1 to 12 carbon atoms, or a benzyl group) at least selected from the group consisting of It is characterized by containing a water-soluble polymer obtained by polymerizing a monomer component containing one kind of monomer.

According to a second aspect of the present invention, there is provided a water-containing soil improver according to the first aspect of the present invention, wherein the monomer component comprises N-vinylacetamide and And / or methoxypolyethylene glycol (meth) acrylate.

According to a third aspect of the present invention, there is provided a method for improving a hydrated soil, wherein the above-mentioned object is attained by mixing the hydrated soil improver according to any one of the first to second aspects with the hydrated soil. It is characterized by:

According to a fourth aspect of the present invention, there is provided a method for improving a hydrated soil, wherein the hydrated soil is improved to a granular form. I have.

According to each of the above-described structures, it is possible to transport the hydrous soil, which is usually discarded as sludge, by truck, for example, a solidified material improved to a state where a person can walk on it, more preferably It can be improved to a solidified product having sufficient strength and a predetermined particle size and finely divided into particles. As a result, the improved hydrous soil can be effectively used for backfilling, agricultural and horticultural purposes, and the like, for example, as a substitute for sand, and can be reused as resources. Also,
If the hydrous soil after improvement is made into a granular solidified product, water permeability when backfilled on the ground can be improved, and the hydrous soil can be reused in a wider range. As a result, environmental conservation, resource saving, and the life of the disposal site can be prolonged, and the disposal cost of hydrous soil can be reduced.

According to the first and second aspects of the present invention, the improver contains a water-soluble polymer obtained by polymerizing a monomer component containing a monomer having a specific molecular structure. I have. The above-mentioned water-soluble polymer does not have a functional group affected by ions contained in hydrous soil in the monomer unit having the specific molecular structure constituting the polymer. Therefore, it is possible to provide an improver whose performance and use amount are hardly affected by ions contained in the hydrous soil.

Hereinafter, the present invention will be described in detail. The hydrated soil solidified (improved) by the improver and the improvement method according to the present invention may be of any kind, and even clay or silt which has been conventionally difficult to reuse can be used as an improved soil.
For example, "Manual for Construction Site Use Technology" (1994)
Year, issued by the Japan Civil Engineering Research Center), solidified material that does not correspond to construction sludge, that is, it can be transported by truck, for example, solidified material that allows humans to walk on it, more preferably It is possible to obtain a solidified product having sufficient strength and a fine particle size having a predetermined particle size.

As the above-mentioned wet soil, specifically, for example, the soil generated during excavation in excavation work employing the underground continuous wall method, the mud shield method or the like is separated into earth and sand and mud, Sludge obtained as a dewatered cake, etc. after dewatering press by dewatering press etc .; muddy water generated during construction work is left in a sedimentation tank, sludge obtained as sediment; excavated soil, soft soil Sludge such as hydrated stone powder generated in quarries and quarries.

The hydrated soil is JIS A 1203
(Water content (g))
/ Solid content (g)) x 100 "is 20% to 2
Those within the range of 00% are preferable, and those within the range of 50% to 150% are more preferable. A water-containing soil having a water content of more than 200% has a large water content (hereinafter referred to as "moisture content"), so that a large amount of the improver must be used, and the cost of the improver increases, which is not preferable.

The source of the hydrated soil is not particularly limited, and the hydrated soil may contain bentonite in addition to clay and silt.

The improving agent and the improving method according to the present invention include:
As described above, the present invention can be applied irrespective of the source of the hydrated soil. Among them, it is particularly suitable for the hydrated soil generated in the Kanto region. According to the survey of construction by-products, the amount of construction waste generated by the Kanto Regional Construction Bureau is highest in Japan. However, construction-generated soil generated in the Kanto region generally contains a large amount of Kanto loam (volcanic ash clay), silt, clay, and the like, and is difficult to solidify into granules. Therefore, while the reuse of hydrous soil containing generated soil generated in the Kanto region is considered desperate, according to the present invention, conventionally, it is difficult to solidify into granular form, the hydrous soil generated in the Kanto region, It can be a solidified product which is finely divided into particles having high strength and a predetermined particle diameter.

The water-soluble polymer (hereinafter, simply referred to as a polymer) used as an agent for improving the hydrous soil of the present invention includes a monomer represented by the general formula (1) and a monomer represented by the general formula (2) ) Is a polymer obtained by polymerizing a monomer component containing at least one monomer selected from the group consisting of the monomers represented by the formula (1), and has water solubility.

The polymer is at least one monomer selected from the group consisting of a monomer represented by the general formula (1) and a monomer represented by the general formula (2) Can be easily obtained by (co) polymerizing or by copolymerizing with another monomer copolymerizable with the monomer (hereinafter simply referred to as other monomer). it can. That is, the monomer component is represented by the general formula (1)
Or contains only at least one monomer selected from the group consisting of monomers represented by the general formula (2), or Contains monomers.

Specific examples of the monomer represented by the above general formula (1) include nonionic monomers such as N-vinylformamide and N-vinylacetamide.
Among the above exemplified monomers, N-vinylacetamide is more preferred.

The monomer represented by the general formula (2) is a divalent group formed by polymerizing 0 to 100 ethylene oxides and / or propylene oxides in the molecule (in the case of ethylene oxide, k in the formula is Is 2, that is, -C ₂ H ₄ O
And in the case of propylene oxide, k in the formula is 3,
That is, a -C ₃ H ₆ O- and is). Also,
The substituent represented by R ₄ in the general formula (2) has 1 carbon atom.
In the case of a phenyl group having an alkyl group of 1 to 12 or an alkyl group of 1 to 12 carbon atoms, the alkyl group may be linear or branched.
It may be annular.

Specific examples of the monomer represented by the general formula (2) include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, polyethylene glycol (meth) acrylate, and methoxypolyethylene glycol. (Meth) acrylate,
Phenoxy polyethylene glycol (meth) acrylate, (meth) allyl alcohol, ethylene oxide adduct of (meth) allyl alcohol, propylene oxide adduct of (meth) allyl alcohol, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) ) Acrylate, isobutyl (meth) acrylate,
And other nonionic monomers. Among the above exemplified monomers, a monomer having a divalent group formed by polymerization of ethylene oxide in the molecule is more preferable, and hydroxyethyl (meth) acrylate and methoxypolyethylene glycol (meth) acrylate Is more preferred.

As the monomer represented by the general formula (1) or (2), only one type may be used, or two or more types may be used in combination. And among the monomers exemplified above, N-vinylacetamide and methoxypolyethylene glycol (meth) acrylate are particularly preferred. That is, it is particularly preferable that the monomer component contains N-vinylacetamide and / or methoxypolyethylene glycol (meth) acrylate.

The other monomer is not particularly limited as long as it is a monomer copolymerizable with the monomer represented by the general formula (1) or (2). is not. That is, structural units other than the monomer units represented by the general formula (1) or the general formula (2), which constitute the polymer according to the present invention, are not particularly limited. As other monomers, specifically, for example, 2-acrylamido-2-methylpropanesulfonic acid, (meth) allylsulfonic acid, allyloxybenzenesulfonic acid, 2-humanperoxy-
3- (2-propenyloxy) propanesulfonic acid, isopropenylsulfonic acid, styrenesulfonic acid, vinylsulfonic acid, allylphosphonic acid, isopropenylphosphonic acid, vinylphosphonic acid, sulfoethyl (meth) acrylate, sulfonated isoprene, phosphonate Monoethylenically unsaturated acids such as ethyl methacrylate and alkali metal salts and ammonium salts of these monomers; vinyl esters such as vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate and vinyl cinnamate; methyl Alkyl vinyl ethers such as vinyl ether and ethyl vinyl ether; 3-methyl-3-buten-1-ol, 3-methyl-2
-Unsaturated alcohols such as buten-1-ol and 2-methyl-3-buten-2-ol; aldehyde group-containing vinyl monomers such as acrolein; and nitrile group-containing vinyl monomers such as (meth) acrylonitrile; (Meth) acrylamide, Nt-
And monomers containing a functional group other than those described above, such as butylacrylamide, styrene, and N-vinyl-2-pyrrolidone. One of these other monomers may be used alone, or two or more thereof may be used in combination. Among the other monomers exemplified above, 2-acrylamido-2-methylpropanesulfonic acid, sulfoethyl (meth) acrylate, and N-vinyl-2-pyrrolidone are particularly preferred.

In the present invention, the proportion of the monomer represented by the general formula (1) or the general formula (2) in the monomer component, that is, all the monomer units constituting the polymer The ratio of the monomer unit to the total is preferably 85 mol% or more, more preferably 90 mol% or more, and most preferably 100 mol%. When the proportion of the monomer is less than 85 mol%, the performance of the obtained improver is easily affected by the ions contained in the hydrous soil, and in some cases, the hydrous soil cannot be granulated. It is not preferable.

The method for producing the polymer, that is, the method for polymerizing the monomer component is not particularly limited. For example, a polymerization method using a polymerization initiator such as a radical polymerization initiator; ionizing radiation; Conventionally known various methods such as a polymerization method of irradiating radiation such as rays or ultraviolet rays; a polymerization method of heating; and the like can be employed.

As the radical polymerization initiator, peroxide-based, redox-based, or azo-based initiators can be used. Specifically, for example, ammonium persulfate, potassium persulfate, hydrogen peroxide, peroxides Peroxides, such as benzoyl and t-butyl peroxide, which are suitably used in peroxides and redox systems; sodium bisulfite, sodium metabisulfite, ammonium ferrous sulfate, L-ascorbic acid, triethanolamine, etc. 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2-aminopropane)
Dihydrochloride, 2,2'-azobisisobutylamide dihydrate,
Azo initiators such as 2,2′-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride; and the like, but are not particularly limited. The amount of the polymerization initiator used and the reaction conditions for the polymerization reaction are not particularly limited.

In the present invention, the weight average molecular weight of the obtained polymer is not particularly limited, but may be 100,000
More preferably greater than 1,000,000, and even more preferably greater than 1,000,000.

When the weight average molecular weight of the above polymer is less than 100,000, there is a possibility that the improved hydrous soil cannot be granulated. As a result of the study by the present inventors, the hydrous soil generated in the Kanto region may not be granulated when the weight average molecular weight of the polymer is small, specifically, when it is less than 100,000, It has been found that the larger the weight average molecular weight, the smaller the amount of the polymer required for granulation. Further, as a result of further study by the present inventors, if the amount of the polymer used is equal, the larger the weight-average molecular weight of the polymer is, the more improved the hydrous soil, that is, the solidified product of the hydrous soil is industrial waste. It was found that the particles could be made finer (the particle size could be reduced) within a range that did not conform to the provisions of the product.

In the present invention, the weight average molecular weight of the above polymer is not particularly limited as long as it is larger than 100,000, but if it exceeds 20,000,000, it increases when the above polymer is mixed with hydrous soil. A viscous effect may be caused to make it impossible to mix the two uniformly, and it is difficult to produce the polymer. For this reason, the upper limit of the weight average molecular weight of the polymer is not particularly limited, but is preferably substantially 20,000,000 or less.

The above-mentioned polymer may be used as an aqueous solution or an emulsion. However, from the viewpoint of handleability and mixing properties, the above-mentioned polymer is preferably dried and pulverized as necessary to be used as a powder. More preferred. In addition, the drying method and the pulverizing method of the polymer are not particularly limited.

When the above polymer is used as a powder (particle), the particle diameter of the polymer is preferably in the range of 0.01 mm to 2 mm, more preferably in the range of 0.02 mm to 1 mm.
If the particle size of the polymer exceeds 2 mm, the amount of the polymer required to make the solidified product finer must be increased, which increases the cost, which is not preferable. On the other hand, when the particle size of the polymer is less than 0.01 mm, dust is easily generated when the polymer is handled, and the polymer is easily absorbed by moisture. Accordingly, workability is reduced, and when added to hydrous soil, flour is generated. For this reason, in order to finely solidify the solid obtained by improving the hydrous soil, the amount of use must be increased, which increases the cost, which is not preferable.

The amount of the polymer used is preferably in the range of 0.01 to 5 parts by weight based on 100 parts by weight of the hydrated soil,
The content is more preferably in the range of 0.02 parts by weight to 1 part by weight. If the amount of the polymer is less than 0.01 part by weight, it is not preferable because the solidified product of the hydrous soil cannot be finely divided. Further, even when the amount of the polymer used is more than 5 parts by weight, the effect is almost the same as when the polymer is used within the above range. Accordingly, an excessively used polymer is wasted, which is not preferable. When the polymer is used in the form of an aqueous solution, the amount of the polymer used indicates the amount (pure content) of the polymer in the aqueous solution.

As described above, the improver for hydrous soil according to the present invention is a polymer having predetermined properties and the like, that is, a monomer represented by the general formula (1), It is composed of a polymer obtained by polymerizing a monomer component containing at least one monomer selected from the group consisting of the monomers represented by (2). Next, an improvement method for improving water-containing soil using the improver having the above-described configuration will be described below.

In the improvement method according to the present invention, by mixing the above-mentioned improving agent (that is, the above-mentioned polymer) with the hydrated soil, the soil can be transported as an improved soil by truck. It is possible to obtain a solidified material that can be walked on by a person, and more preferably a solidified material having sufficient strength and a predetermined particle diameter, which is finely divided into particles. As a mixer used when mixing the hydrous soil and the above-mentioned improver, a device capable of stirring and mixing without kneading the mixture of both is preferable, and imparts a shearing force to the mixture of both. A device in which the shape of the stirring blade is formed in a rod shape, a fishing hook shape, or the like is preferable so that stirring can be performed. In other words, the shape of the stirring blade, which expands in the direction perpendicular to the moving direction of the mixture that is moved by stirring and mixing as much as possible, can suppress coarsening of the particle diameter due to kneading, and can be applied to the stirring blade and the inner wall of the device. Is preferable because the adhesion of the mixture can be prevented.

Examples of such a device include a horizontal axis type mixer and a vertical axis type mixer. As the horizontal shaft type mixer, for example, a single-shaft and multi-shaft paddle-type mixer is preferable. As the vertical axis type mixer, for example, a pan mixer type mixer is preferable, a planetary type mixer is more preferable, and among these planetary type mixers, a soil mixer, a mortar mixer, and an Eirich mixer are further preferable. While mixing the hydrated soil and the improver using the above mixer, and using the shearing force generated by the stirring blade, the mixture has a particle size in the range of 0.1 mm to 50 mm, preferably in the range of 0.3 mm to 10 mm. It can be refined (granularly solidified) into particles inside. The method of mixing the hydrated soil with the improver is not particularly limited.

Next, if necessary, a hydraulic substance is added to the obtained improved soil (granulated solidified material) and mixed. In addition, if the hydraulic substance is mixed before mixing the improver with the hydrous soil,
The hydrated soil cannot be solidified granularly.

The hydraulic substance is not particularly limited as long as it hardens in water, and specific examples thereof include cement, quicklime, slaked lime, and the like.
Gypsum, and mixtures thereof. Among the hydraulic materials exemplified above, cement and quicklime are more preferred.

As the above cement, various known cements can be used. Specific examples of the cement include Portland cement such as ordinary Portland cement, early-strength Portland cement, and ultra-high-strength Portland cement; blast furnace cement; alumina cement; calcium cement; fly ash cement; There is no particular limitation.

The amount of the hydraulic substance to be used per 100 parts by weight of the hydrated soil is preferably in the range of 1 part by weight to 20 parts by weight, and more preferably in the range of 1 part by weight to 10 parts by weight. If the amount of the hydraulic substance used is less than 1 part by weight, the strength (described later) of the improved soil (granulated solidified material) may be insufficient. Further, even when the amount of the hydraulic substance used is more than 20 parts by weight, the effect is almost the same as when the hydraulic substance is used within the above range. Therefore, an excessively used hydraulic substance is wasted, which is not preferable.

The mixer used for mixing the hydraulic material with the improved soil (granulated solidified material) is not particularly limited, but an apparatus capable of stirring and mixing the two without kneading the mixture. Is preferred. In addition, when mixing using such a mixer, the shearing force is not applied as much as when mixing the above-mentioned hydrated soil and the improver, and a hydraulic substance is attached to the surface of the improved soil (granulated solidified material). It is preferable to stir so as to glaze. As a result, an improved soil (granulated solid) in which the hydraulic substance adheres almost uniformly to the surface of the improved soil (granulated solid) is obtained. In addition, the hydraulic substance may partially enter the inside of the improved soil (granular solidified material). Further, the method of mixing the improved soil (granular solidified material) and the hydraulic substance is not particularly limited.

The obtained improved soil (granulated solidified material) may be immediately backfilled, but if left at room temperature for about 3 days to about 7 days, the hydraulic substance is cured, so that a predetermined strength is obtained. Can be prepared.

The improved soil obtained as described above can be transported by truck, and is, for example, a solidified material improved so that a person can walk on it, more preferably a granular solidified material. Therefore, the improved soil does not correspond to industrial waste and can be reused. In particular, granular solids
Since it has a predetermined particle size and strength, it can be reused as a resource such as a substitute for sand without performing operations such as crushing and sieving. That is, in civil engineering work in which excavation holes need to be backfilled, backfill can be performed using the granular solidified material without separately preparing sand or the like. In addition, since the granular solidified material can improve water permeability when backfilled on the ground, it is possible to reuse the hydrous soil in a wider range. The particulate solidified material is, for example, a backfill material for backfilling a buried pipe or a structure, a barrier layer material as artificial sand, a vegetation base material for spraying a slope to process the slope, a soil improvement material , A water retaining material, a water permeable material, a water quality improving material, and the like. As described above, the use of the improving agent and the improving method of the present invention makes it possible to reuse hydrated soil that is usually discarded as sludge, so that environmental conservation, resource saving, and life extension of disposal sites can be achieved. At the same time, the disposal cost of hydrous soil can be reduced.

Further, according to the above constitution, the improving agent is a monomer having a specific molecular structure, that is, a monomer represented by the general formula (1) and a monomer represented by the general formula (1) It includes a polymer obtained by polymerizing a monomer component containing at least one monomer selected from the group consisting of the monomers represented by 2). In the above polymer, the monomer unit having the specific molecular structure constituting the polymer does not have a functional group affected by ions contained in hydrous soil. Therefore, it is possible to provide an improver whose performance and use amount are hardly affected by ions contained in the hydrous soil.

[0051]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited thereto. The weight average molecular weight (Mw) of the polymer as an improving agent was measured by gel permeation chromatography (GPC).

Example 1 Water containing soil was obtained by dewatering and pressing mud generated by excavation work employing the mud shield construction method in the Kanto region. The water content of the water-containing soil was 62% by weight.

Next, a predetermined amount of the above-mentioned hydrated soil was charged into a planetary mixer (planetary mixer) equipped with a hook-type hook-type stirring blade. Subsequently, the poly (N-vinylacetamide) (A) in the form of powder as an improver according to the present invention was added to the hydrous soil while stirring the hydrous soil at 160 rpm.
Was added and mixed little by little so that the ratio to the above-mentioned hydrated soil was 0.1% by weight. The poly (N-vinylacetamide) (A) had a weight average molecular weight (Mw) of 1,600,000 and a particle size of 0.05 mm to 0.25 mm.

As a result, a finely divided product having a particle diameter in the range of 0.3 mm to 5 mm and an average particle diameter of 1 mm was obtained. afterwards,
The finely divided product was left at room temperature for 7 days to obtain a granular solidified product. Table 1 shows the main solidification conditions and the particle size of the finely divided material.
Shown in

[Example 2] The muddy water of Example 1 was dewatered and pressed in the same mixer as in Example 1 to obtain a water content of 1
A predetermined amount of 05% hydrous soil was charged. Subsequently, while stirring the hydrous soil at 160 rpm, the powdery poly (N-vinylacetamide) (A) was gradually added to the hydrous soil so that the ratio to the hydrous soil was 0.3% by weight. The mixture was added and mixed to obtain a granular material. Next, the obtained granules are
While stirring at 60 rpm, quick lime as a hydraulic substance was added to the granules little by little so that the ratio to the above-mentioned hydrous soil was 3% by weight.

As a result, a finely divided product having a particle diameter in the range of 0.5 mm to 10 mm and an average particle diameter of 2 mm was obtained. afterwards,
The finely divided product was left at room temperature for 7 days to obtain a granular solidified product. Table 1 shows the main solidification conditions and the particle size of the finely divided material.
Shown in

Example 3 The same water content as that of Example 1 was obtained by subjecting the muddy water of Example 1 to dehydration pressing.
A predetermined amount of 05% hydrous soil was charged. Subsequently, while stirring the hydrous soil at 160 rpm, powdery N-vinylacetamide / powder as an improver according to the present invention was added to the hydrous soil.
The hydroxyethyl acrylate copolymer (B) was added and mixed little by little so that the ratio to the hydrous soil was 0.3% by weight.

In the above N-vinylacetamide / hydroxyethyl acrylate copolymer (B), the molar ratio of N-vinylacetamide to hydroxyethyl acrylate is
The weight average molecular weight (Mw) of the N-vinylacetamide / hydroxyethyl acrylate copolymer (B) is 80/20.
The particle size was in the range of 0.05 mm to 0.25 mm.

As a result, a finely divided product having a particle diameter in the range of 1 mm to 10 mm and an average particle diameter of 3 mm was obtained. Thereafter, the finely divided product was left at room temperature for 7 days to obtain a granular solidified product.
Table 1 shows the main solidification conditions, the particle size of the finely divided material, and the like.

[Example 4] A water content ratio of 62 obtained by dewatering and pressing the muddy water of Example 1 in the same mixer as in Example 1.
% Of hydrous soil was charged in a predetermined amount. Subsequently, the hydrous soil is
While stirring at 160 rpm, the powdered
The N-vinylacetamide / hydroxyethyl acrylate copolymer (B) was added little by little so that the ratio to the above-mentioned hydrous soil was 0.1% by weight, and mixed to obtain a granular material. Next, while stirring the obtained granules at 160 rpm,
Fly ash as a hydraulic substance was added to the granules little by little so that the ratio to the above-mentioned hydrous soil was 5% by weight.

As a result, a finely divided product having a particle diameter in the range of 2 mm to 20 mm and an average particle diameter of 4 mm was obtained. Thereafter, the finely divided product was left at room temperature for 7 days to obtain a granular solidified product.
Table 1 shows the main solidification conditions, the particle size of the finely divided material, and the like.

[0062]

[Table 1]

Example 5 The same mixer as in Example 1 was prepared by dewatering and pressing the muddy water of Example 1 to a water content of 62.
% Of hydrous soil was charged in a predetermined amount. Subsequently, the hydrous soil is
While stirring at 160 rpm, a powdery polymer (C) of methoxypolyethylene glycol methacrylate as an improver according to the present invention was slightly added to the hydrous soil so that the ratio to the hydrous soil was 0.3% by weight. Each time,
Mixed.

The average degree of polymerization of ethylene glycol in methoxy polyethylene glycol methacrylate was 10 mol. The weight average molecular weight (Mw) of the polymer (C) of the methoxypolyethylene glycol methacrylate
Was 800,000 and the particle size was in the range of 0.02 mm to 1 mm.

As a result, a finely divided product having a particle diameter in the range of 1 mm to 20 mm and an average particle diameter of 4 mm was obtained. Thereafter, the finely divided product was left at room temperature for 7 days to obtain a granular solidified product.
Table 2 shows the main solidification conditions, the particle size of the finely divided material, and the like.

Example 6 The same mixer as in Example 1 was subjected to dewatering press of the muddy water of Example 1 to obtain a water content ratio of 1
A predetermined amount of 05% hydrous soil was charged. Subsequently, while stirring the water-containing soil at 160 rpm, the powdery methoxypolyethylene glycol methacrylate / hydroxyethyl acrylate copolymer (D) as an improver according to the present invention was added to the water-containing soil while stirring the water-containing soil. Ratio to 0.3
The mixture was added little by little so as to obtain a weight percentage, and a granular material was obtained.

The average degree of polymerization of ethylene glycol in methoxy polyethylene glycol methacrylate was 10 mol. The molar ratio of methoxypolyethylene glycol methacrylate / hydroxyethyl acrylate in the methoxypolyethylene glycol methacrylate / hydroxyethyl acrylate copolymer (D) is 90/10, and the methoxypolyethylene glycol methacrylate / hydroxyethyl acrylate copolymer (D ) Has a weight average molecular weight (Mw) of 2,000,000 and a particle size of 0.
It was in the range of 05mm to 0.25mm.

While stirring the obtained granules at 160 rpm, blast furnace cement as a hydraulic substance was added to the granules.
It was added and mixed little by little so that the ratio to the above-mentioned hydrous soil became 10% by weight.

As a result, a finely divided product having a particle diameter in the range of 0.3 mm to 10 mm and an average particle diameter of 2 mm was obtained. afterwards,
The finely divided product was left at room temperature for 7 days to obtain a granular solidified product. Table 2 shows the main solidification conditions and the particle size of the finely divided material.
Shown in

[0070]

[Table 2]

[Comparative Example 1] The same mixer as that of Example 1 was used to dewater and press the muddy water of Example 1 to obtain a water content of 62.
% Of hydrous soil was charged in a predetermined amount. Subsequently, the hydrous soil is
While stirring at 160 rpm, Portland cement as a hydraulic substance was added little by little to the hydrous soil so that the ratio to the hydrous soil was 5% by weight. However, the hydrated soil solidifies in blocks,
No granules could be obtained. Table 3 shows the main solidification conditions.
Shown in

[Comparative Example 2] A water content ratio of 62 obtained by dewatering and pressing the muddy water of Example 1 in the same mixer as in Example 1.
% Of hydrous soil was charged in a predetermined amount. Subsequently, the hydrous soil is
While stirring at 160 rpm, a powdery sodium polyacrylate (E) as a modifier for comparison was added to the hydrous soil.
Was added little by little so that the ratio to the above-mentioned hydrated soil was 0.2% by weight, and mixed to obtain a granular material.

The sodium polyacrylate (E) had a neutralization ratio of 100 mol%, a weight average molecular weight (Mw) of 1,100,000,
Particle size was in the range of 0.05 mm to 1 mm.

However, no granular material could be obtained. Table 3 shows the main solidification conditions.

[Comparative Example 3] The muddy water of Example 1 was dewatered and pressed in the same mixer as in Example 1 to obtain a water content of 1
A predetermined amount of 05% hydrous soil was charged. Subsequently, while stirring the hydrated soil at 160 rpm, a powdery sodium acrylate / acrylamide copolymer (F) as a modifier for comparison was added to the hydrated soil at a ratio to the hydrated soil.
It was added and mixed little by little so as to become 0.5% by weight.

The molar ratio between sodium acrylate and acrylamide in the sodium acrylate / acrylamide copolymer (F) is 50/50, and the weight average molecular weight (Mw) of the sodium acrylate / acrylamide copolymer (F) is Was 1,000,000, and the particle size was in the range of 0.05 mm to 0.15 mm.

While the obtained granules were stirred at 160 rpm, quick lime as a hydraulic substance was added to the granules little by little so that the ratio to the hydrous soil became 10% by weight. However, no granular material could be obtained. Table 3 shows the main solidification conditions.

[0078]

[Table 3]

From the results shown in Tables 1 and 2, it is understood that the use of the improver according to the present invention can make the above-mentioned hydrous soil finer. From the results shown in Table 3, when no improver was contained, or when the above-mentioned general formula (1)
Alternatively, it can be seen that the comparative improver containing a polymer obtained by polymerizing a monomer component not containing the monomer represented by the general formula (2) cannot granulate the above-mentioned hydrous soil. .

[0080]

As described above, the improving agent for hydrous soil according to claim 1 of the present invention has the general formula (1)

[0081]

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(Wherein R ₁ represents a hydrogen atom or a methyl group, and R ₂ represents a hydrogen atom, a methyl group or an ethyl group) and a monomer represented by the general formula (2):

[0083]

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(Wherein, R ₃ represents a hydrogen atom or a methyl group, X represents a —COO— group or a —CH ₂ O— group,
k is 2 or 3; n is an integer from 0 to 100;
₄ represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a phenyl group, a phenyl group having an alkyl group having 1 to 12 carbon atoms, or a benzyl group) at least selected from the group consisting of The composition includes a water-soluble polymer obtained by polymerizing a monomer component containing one kind of monomer. As described above, the improver for hydrous soil according to claim 2 of the present invention is configured such that the monomer component contains N-vinylacetamide and / or methoxypolyethylene glycol (meth) acrylate.

According to the above configuration, the improved hydrous soil can be transported by truck, for example, a solidified product improved to a state where a person can walk on it, more preferably, a solid product having sufficient strength and Since it can be solidified into a fine particle having a predetermined particle size, the water-containing soil normally discarded as sludge can be effectively used as a resource such as a substitute for sand (reuse). It has the effect that it can be done. In addition, since the solidified material after improvement can be reused, it is possible to save the environment, save resources, extend the life of disposal sites, and reduce the disposal cost of hydrous soil. Play. Further, according to the above configuration, the improver contains a water-soluble polymer obtained by polymerizing a monomer component containing a monomer having a specific molecular structure. The above-mentioned water-soluble polymer does not have a functional group affected by ions contained in hydrous soil in the monomer unit having the specific molecular structure constituting the polymer. Therefore, there is also an effect that an improving agent whose performance and usage amount are hardly affected by ions contained in the hydrous soil can be provided.

The method for improving a hydrous soil according to claim 3 of the present invention comprises, as described above, a method of mixing the hydrous soil improver according to any one of claims 1 and 2 with the hydrous soil. It is. The method for improving a hydrous soil according to claim 4 of the present invention comprises:
As described above, this is a method for improving the above-mentioned hydrous soil into granules.

According to the above-mentioned method, the improved hydrous soil can be transported by truck, for example, a solidified product improved so that a person can walk on it, and more preferably, having sufficient strength and strength. Since it can be solidified into a fine particle having a predetermined particle size, the water-containing soil normally discarded as sludge can be effectively used as a resource such as a substitute for sand (reuse). It has the effect that it can be done. In addition, since the solidified material after improvement can be reused, it is possible to save the environment, save resources, extend the life of disposal sites, and reduce the disposal cost of hydrous soil. Play.

Claims (4)

[Claims] 1. A compound of the general formula (1) (Wherein R ₁ represents a hydrogen atom or a methyl group, and R ₂ represents a hydrogen atom, a methyl group or an ethyl group) and a monomer represented by the general formula (2): (Wherein, R ₃ represents a hydrogen atom or a methyl group, and X represents-
Represents a COO— group or a —CH ₂ O— group, k is 2 or 3, n is an integer of 0 to 100, and R ₄ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a phenyl group, Number 1
Water-soluble polymer obtained by polymerizing a monomer component containing at least one monomer selected from the group consisting of monomers represented by the following formulas: An agent for improving a hydrous soil, comprising: 2. The improver for hydrous soil according to claim 1, wherein the monomer component contains N-vinylacetamide and / or methoxypolyethylene glycol (meth) acrylate. 3. A method for improving a hydrous soil, comprising mixing the hydrous soil improver according to claim 1 into the hydrous soil. 4. The method for improving hydrous soil according to claim 3, wherein the hydrous soil is improved to a granular form.