JP2554428B2 - How to remove dissolved oil in water - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing dissolved oil in water. More specifically, oils that are slightly or slightly soluble in water dissolved in water such as wastewater and polluted water sources, and a wide variety of water-soluble substances and impurities such as water-insoluble colloidal particles The present invention relates to a method for removing dissolved oil in water, which can be selectively removed even when coexisting, and can significantly shorten the time required for the removal treatment.

[0002]

2. Description of the Related Art In recent years, there has been a strong demand for a technique for advanced purification of wastewater for the purpose of environmental protection and reuse of factory and domestic wastewater. In addition, due to pollution of rivers and lakes, even when these are used as a water source and used as tap water such as tap water, a technique for advanced purification of sewage is strongly desired.

The contents of wastewater and wastewater mainly include organic compounds, water-soluble inorganic compounds, solid particles, various bacteria, and the like. Among them, oils are slightly dissolved in water, and the environment and human body Adversely or cause problems such as offensive odor, unpleasant taste, foaming and coloring. In particular, recently, the removal of halogen compounds, which are extremely harmful to the human body and dissolved in water, has become a major issue in terms of environmental protection.

As a method for removing these dissolved oils in water, there has been used a method in which granular activated carbon is mixed with primary-treated wastewater or sewage and adsorption treatment of the dissolved oils is carried out for advanced purification. However, activated carbon exhibits adsorption ability not only for oil components intended for removal but also for impurities other than oil components such as water-soluble substances and poorly water-soluble colloidal particles. The adsorption sites and pores of were quickly blocked by impurities other than oil, and the oil removal effect did not continue. In addition, activated carbon has a drawback in that it cannot sufficiently remove oil with waste water or sewage mixed with high-concentration oil, because activated carbon has an insufficient ability to adsorb oil. Furthermore, since granular activated carbon has a slow adsorption rate, it is necessary to provide sufficient contact time with wastewater and sewage, and when filling a column or the like to remove oil, the water flow rate cannot be increased and treatment efficiency is improved. There was a problem that became very bad.

As a means for solving these problems, some methods of using a certain polymer as an oil-in-oil absorbent have been reported. For example, an absorption polymer of a chlorine-based solvent obtained by crosslinking a chain polymer that is soluble in a chlorine-based organic solvent by adding a crosslinking agent or irradiating with a radiation or an electron beam, and a solvent absorption filtration tower filled with them. Equipped with a chlorine-based solvent wastewater exhaust treatment device (Japanese Patent Laid-Open No. 64-80441), carbon number 8 to 3
Method for removing dissolved oil in water by allowing dissolved oil to be absorbed and held by an absorbent for dissolved oil in water, which is composed of a crosslinked polymer of alkyl (meth) acrylate of 0 (JP-A-4-145904)
Etc. However, when these polymers are used as an oil absorbent, it takes a long time to absorb the dissolved oil in water, and the processing efficiency is not sufficient. Furthermore, these polymers swell themselves when the oil is absorbed to some extent, and the particles agglomerate strongly,
When it is used by being packed in a column or the like, there is a problem that the pressure loss is large and it is difficult to pass the liquid at a high flow rate.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above problems of the prior art. Therefore, an object of the present invention is to disperse a slightly soluble or sparingly soluble oil component in water, such as waste water or a contaminated water intake source, into a wide variety of water-soluble substances or water-insoluble colloidal particles. Another object of the present invention is to provide a method for removing dissolved oil in water, which can selectively remove in a very short time even in the presence of impurities such as.

[0007]

Means for Solving the Problems The present inventors have used a particulate material obtained by complexing a specific oil-absorptive cross-linked polymer and a specific organic acid metal salt as an in-water oil absorbent,
The inventors have found that the above-mentioned objects are achieved and completed the present invention.

That is, according to the present invention, the monomers (A) 90 to 9 having one polymerizable unsaturated group in the molecule whose main component is a monomer having a solubility parameter (SP value) of 9 or less.
Crosslinking monomer (B) 0.001-1 with 9.999% by weight and at least two polymerizable unsaturated groups in the molecule
0% by weight (however, the total of the monomers (A) and (B) is 1
30 to 99 parts by weight of an oil-absorptive cross-linked polymer (I) obtained by polymerizing a monomer component consisting of
Granules consisting of 1 to 70 parts by weight of an organic acid metal salt (II) having a solubility of 1 g or less in 100 g of water at 0 ° C. are used as a water-dissolved oil absorbent, and the oil is dissolved in water to dissolve the oil. The present invention relates to a method for removing dissolved oil in water, which is characterized in that it is absorbed and held by a drug.

[0009]

The solubility parameter (SP value) is generally used as a measure of the polarity of a compound, and in the present invention, the value derived by substituting the Hoy cohesive energy constant into the Small calculation formula is applied. And the unit (cal /
expressed in cm ^{3) 1/2.}

The monomer constituting the main component of the monomer (A) used in the present invention is a monomer having a solubility parameter (SP value) of 9 or less and having one polymerizable unsaturated group in the molecule. If a monomer having a solubility parameter (SP value) of more than 9 is used as the main component of the monomer (A), only a crosslinked polymer having insufficient oil absorption performance can be obtained, which is not preferable.

Examples of the monomer having a solubility parameter (SP value) of 9 or less and having one polymerizable unsaturated group in the molecule include, for example, methyl (meth) acrylate, ethyl (meth) acrylate and butyl (meth). Acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate,
Dodecyl (meth) acrylate, stearyl (meth) acrylate, phenyl (meth) acrylate, octylphenyl (meth) acrylate, nonylphenyl (meth) acrylate, dinonylphenyl (meth) acrylate, cyclohexyl (meth) acrylate, menthyl (meth) Unsaturated carboxylic acid esters such as acrylate, isobornyl (meth) acrylate, dibutyl maleate, didodecyl maleate, dodecyl crotonate, didodecyl itaconate; (di) butyl (meth) acrylamide, (di) dodecyl (meth) acrylamide ,
(Meth) acrylamide having a hydrocarbon group such as (di) stearyl (meth) acrylamide, (di) butylphenyl (meth) acrylamide, (di) octylphenyl (meth) acrylamide; 1-hexene, 1-octene, isooctene, Α-Olefins such as 1-nonene, 1-decene, 1-dodecene; alicyclic vinyl compounds such as vinylcyclohexane; allyl ethers having a hydrocarbon group such as dodecyl allyl ether; vinyl caproate, vinyl laurate, palmitic acid Vinyl ester having a hydrocarbon group such as vinyl and vinyl stearate;
Vinyl ether having a hydrocarbon group such as butyl vinyl ether and dodecyl vinyl ether; aromatic vinyl compounds such as styrene, t-butyl styrene, octyl styrene and the like can be mentioned, and one or more of these monomers can be used. You can Among these, as a monomer that gives better oil absorption performance and oil retention performance,
It has at least one aliphatic hydrocarbon group having 3 to 30 carbon atoms, and is alkyl (meth) acrylate, alkylaryl (meth) acrylate, alkyl (meth) acrylamide, alkylaryl (meth) acrylamide,
The monomer (A) containing as a main component at least one unsaturated compound (a) selected from the group consisting of fatty acid vinyl ester, alkylstyrene and α-olefin is particularly preferable.

Such solubility parameter (SP value)
Is 9 or less, the amount used in the monomer (A) is
The proportion is 50% by weight or more, more preferably 70% by weight or more, based on the total amount of the monomer (A). When the amount of the monomer having the solubility parameter (SP value) of 9 or less in the monomer (A) is less than 50% by weight, only a crosslinked polymer having poor oil absorption performance and oil retention performance can be obtained.

Therefore, in the present invention, 5 monomers having a solubility parameter (SP value) of 9 or less in the monomer (A) are used.
It is necessary that the content of the solubility parameter (SP) is 50% by weight or less in the monomer (A), although the content of SP is 0% by weight or more.
A monomer having one polymerizable unsaturated group may be contained in a molecule whose value) exceeds 9. Examples of such a monomer include (meth) acrylic acid, acrylonitrile, maleic anhydride, fumaric acid, hydroxyethyl (meth) acrylate, polyethylene glycol (meth) acrylate, and methoxypolyethylene glycol (meth) acrylate. You can

Examples of the crosslinkable monomer (B) used in the present invention include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polyethylene glycol-polypropylene glycol di. (Meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di ( (Meth) acrylate, N, N'-methylenebisacrylamide, N, N '
-Alkylene oxide adducts of propylenebisacrylamide, glycerin tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, polyhydric alcohols (eg glycerin, trimethylolpropane or tetramethylolmethane). Examples thereof include polyfunctional (meth) acrylates and divinylbenzene obtained by esterification with and (meth) acrylic acid, and one or more of these crosslinkable monomers can be used.

The proportions of the monomer (A) and the crosslinkable monomer (B) in the monomer component used for producing the crosslinked polymer (I) are the same as those of the monomer (A) and the crosslinkable monomer. The amount of the monomer (A) is 90 to 99.9 based on the total amount of the monomer (B).
99% by weight, the crosslinkable monomer (B) is 0.001-
It is in the range of 10% by weight.

If the amount of the monomer (A) is less than 90% by weight or the amount of the crosslinkable monomer (B) exceeds 10% by weight, the crosslink density of the obtained crosslinked polymer becomes too high and a large amount of oil is obtained. It is not preferable because it cannot be absorbed. Further, when the amount of the monomer (A) exceeds 99.999% by weight or the amount of the crosslinkable monomer (B) is less than 0.001% by weight, the solubility of the obtained crosslinked polymer in oil is increased, and after oil absorption, It is not preferable because the crosslinked polymer is fluidized and oil absorption performance cannot be obtained.

The crosslinked polymer (I) in the present invention contains, for example, the above-mentioned monomer component in an aqueous medium as a protective colloid agent such as polyvinyl alcohol, hydroxyethyl cellulose and gelatin, sodium alkylsulfonate, sodium alkylbenzenesulfonate and polyoxy. It can be produced by dispersing it in the presence of a surfactant such as ethylene alkyl ether or fatty acid soap and carrying out suspension polymerization with an oil-soluble radical polymerization initiator. If necessary, the monomer component may be dissolved in a water-insoluble organic solvent and then suspension-polymerized. Examples of the oil-soluble radical polymerization initiator include organic peroxides such as benzoyl peroxide, lauroyl peroxide and cumene hydroperoxide;
An azo compound such as ′ -azobisisobutyronitrile or 2,2′-azobisdimethylvaleronitrile can be used. The polymerization temperature can be appropriately selected within the range of 0 to 150 ° C. depending on the type of monomer component and the type of polymerization initiator.

In the present invention, as a method for producing the crosslinked polymer (I), there is a method of polymerizing the crosslinked polymer (I) by bulk polymerization and then adjusting the particle size by adding an operation such as pulverization. it can. Bulk polymerization is performed, for example, by pouring a monomer component into a mold in the presence of the above polymerization initiator,
The polymerization may be carried out under the condition of 50 ° C.

In the present invention, the crosslinked polymer (I) has an average particle size of 0. 1 by introducing a pre-suspension step using a homomixer or the like during suspension polymerization and adjusting stirring power during polymerization.
It is preferable that the particles are in the range of 5 to 500 μm.
If the average particle size of the particles of the crosslinked polymer (I) is less than 0.5 μm, the surface area decreases due to the Mamako phenomenon based on the aggregation of the particles, making it difficult to obtain an oil absorbent having an improved oil absorption rate. Become. Further, if the average particle size of the particles of the crosslinked polymer (I) exceeds 500 μm, the oil absorption rate also decreases as the surface area of the crosslinked polymer decreases, which is not preferable.

As the organic acid metal salt (II) in the present invention, a so-called completely neutralized neutral soap, an acidic soap containing excess organic acid, and a basic soap containing excess metal can be used. Moreover, any of monosoap, disoap, and trisoap may be used.

The organic acid constituting the organic acid metal salt (II) is
There is no particular limitation as long as it shows a water-insolubility or poor water-solubility of 1 g or less in 100 g of water at 20 ° C. when forming an organic acid metal salt, and examples thereof include butyric acid, caproic acid, caprylic acid, pelargonic acid, and caprin. Acids, undecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, montanic acid, linear saturated fatty acids such as mericic acid; oleic acid, linoleic acid, linolenic acid, etc. Straight chain unsaturated fatty acids; branched fatty acids such as isostearic acid; fatty acids containing hydroxyl groups such as ricinoleic acid and 12-hydroxystearic acid; benzoic acid; naphthenic acid; abietic acid, rostroic acid such as dextropimaric acid. It is possible to use one or more of these. Among these organic acids, carbon number 3 to 30
Are preferred.

The metal constituting the organic acid metal salt (II) is not particularly limited as long as it exhibits the above-mentioned water-insolubility or poor water-solubility when the organic acid metal salt is formed.
Sodium, potassium, lithium, copper, beryllium, magnesium, calcium, strontium, barium,
Zinc, cadmium, aluminum, cerium, titanium,
Zirconium, lead, chromium, manganese, cobalt, nickel and the like can be mentioned, and one or more of these can be used.

Organic acid metal salt (II) used in the present invention
Preferably has an average particle diameter of 0.05 to 300 μm. If the average particle size is less than 0.05 μm, the powder particles agglomerate to reduce the oil absorption rate, which is not preferable. On the other hand, if the average particle size exceeds 300 μm, the synergistic effect with the crosslinked polymer (I) is difficult to be exhibited, and the absorption rate of the dissolved oil in water cannot be improved, which is not preferable.

The granular material comprising the oil-absorbing crosslinked polymer (I) and the organic acid metal salt (II) effective as the water-soluble oil absorbent in the present invention is the oil-absorbing crosslinked polymer (I) and the organic acid metal salt. It is obtained by mixing and granulating (II) and compounding both. The mixing / granulating method is not particularly limited, and either wet mixing or dry mixing can be adopted, and a conventionally known granulating method can be adopted. The wet mixing is carried out by, for example, dispersing and mixing the oil-absorbing crosslinked polymer (I) and the organic acid metal salt (II) in water in the presence of a surfactant as necessary, aggregating and granulating if necessary, and then filtering. It can be performed by a method of separately drying. Dry mixing is carried out, for example, by using a colloid mill, a kneader or a mixer, and the oil-absorbing crosslinked polymer (I).
And an organic acid metal salt (II) are mixed with each other. At this time, a binder such as water, an organic solvent or a solution of a polymer compound dissolved therein may be added for granulation. In particular, wet mixing is preferable because an aqueous dispersion of the oil-absorbing crosslinked polymer (I) obtained by the suspension polymerization can be mixed with the organic acid metal salt (II) as it is. Also,
A method of mixing the cross-linked polymer (I) obtained by bulk polymerization and the organic acid metal salt (II) while adjusting the particle size by a pulverizing operation or the like can also be adopted.

The water-insoluble oil absorbent used in the present invention comprises the oil-absorbing cross-linked polymer (I) having a small particle size and the organic acid metal salt (II), and therefore has a surface area capable of efficiently absorbing the oil dissolved in water. It is a granular material which is granulated to a size that does not impede water flow when it is stored in a column or the like and has an average particle size of 0.1 to 10 mm. If this average particle size is less than 0.1 mm, water flow may be impeded, and if it exceeds 10 mm, the oil absorption rate may decrease.

The mixing ratio of the oil-absorbing crosslinked polymer (I) and the organic acid metal salt (II) in the water-soluble oil absorbent used in the present invention is 30 to 99 parts by weight of the oil-absorbing crosslinked polymer (I). And the ratio of the organic acid metal salt (II) is 1 to 70 parts by weight. If the amount of the organic acid metal salt (II) is less than 1 part by weight, the particles of the oil-absorbing crosslinked polymer (I) are strongly aggregated with each other, and the rate of absorbing the dissolved oil in water is reduced, which is not preferable. Further, when a large amount of the organic acid metal salt (II) is used in an amount of more than 70 parts by weight, the oil absorption amount and oil retaining performance of the oil-in-water dissolved oil absorbent are deteriorated, which is not preferable.

The oil component to be used in the present invention is not particularly limited as long as it is an oil component slightly or hardly soluble in water. Examples of these oils include pentane, hexane, octane, decane, cyclohexane, benzene, toluene, xylene,
Ethylbenzene, butylbenzene, dodecylbenzene,
Styrene, petroleum ether, petroleum benzine, petroleum naphtha,
Hydrocarbon oils such as petroleum gasoline and kerosene; halogenated hydrocarbon oils such as chloroform, carbon tetrachloride, trichloroethane and trichloroethylene; alcohols oils such as hexanol, octanol and dodecyl alcohol; cresol, xylenol, octylphenol,
Phenolic oils such as nonylphenol; ethers such as diethyl ether, dibutyl ether, butyl vinyl ether, butylphenyl ether; ketones such as hexanone and heptanone; fatty acids such as caproic acid and oleic acid; butyl acetate, amyl acetate Examples of such oils include ester oils.

In the present invention, in order to use the granular material comprising the oil-absorbing crosslinked polymer (I) and the organic acid metal salt (II) as the water-insoluble oil absorbent, the absorbent is mixed with water in which the oil is dissolved. Then, the dissolved oil may be absorbed and retained by the absorbent to be removed, and specifically, a method of using an adsorbent of the dissolved oil in water such as activated carbon or activated alumina which has been conventionally used (for example, a catalytic filtration adsorption method). , Fixed bed adsorption method, moving bed adsorption method, etc.).

According to the contact filtration adsorption method, the absorbent and waste water may be mixed by stirring in a mixing tank, and then the absorbent may be separated by filtration or settling, and either a batch system or a continuous system may be adopted. it can. Furthermore, by using a multi-adsorption or multi-stage adsorption device, it is possible to purify waste water and wastewater to a higher degree.

On the other hand, the fixed bed adsorption method is carried out by sending wastewater to a layer filled with an absorbent and replacing the absorbent with a new one after the passage of water. A multi-bed type can also be adopted.

Further, the moving bed adsorption method is carried out by a step of sequentially taking out the absorbent that has saturatedly absorbed the oil from the adsorption tower, regenerating the absorbent, and then returning it to the adsorption tower again. that time,
The method of regenerating the absorbent can be selected according to the type of oil recovered. For example, an absorbent that has absorbed low boiling oil can be easily regenerated by heating and evaporating the oil. The absorbent that has absorbed the high boiling point oil is regenerated by extracting the oil with another low boiling point solvent and then heating and evaporating the low boiling point solvent.

In the present invention, the granular material comprising the oil-absorbent crosslinked polymer (I) and the organic acid metal salt (II) may be used in combination with a conventional adsorbent such as activated carbon, bentonite or activated silica, or polypropylene. It can also be used by supporting it on a porous substrate such as polyolefin such as polyethylene or polyethylene, polyester, nylon or polyurethane.

[0033]

EXAMPLES Next, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto. In the examples, parts represent parts by weight unless otherwise specified.

[0034]

Example 1 A 500 ml flask equipped with a thermometer, a stirrer, a gas inlet tube, and a reflux condenser was charged with polyoxyethylene alkyl ether (manufactured by Nippon Shokubai Co., Ltd., trade name: Sophthanol 150, which is also used in the following examples. 3 parts (commercially used) were dissolved in 300 parts of water and charged, and the inside of the flask was replaced with nitrogen while stirring and heated to 40 ° C. under a nitrogen stream. Then, 99.794 parts of nonylphenyl acrylate (SP value: 8.3) as the monomer (A), 0.206 parts of 1,6-hexanediol diacrylate as the crosslinkable monomer (B), and a polymerization initiator. Was added to the flask all at once, and the mixture was vigorously stirred under the condition of 750 rpm.

Then, the temperature inside the flask was raised to 80 ° C. and maintained at the same temperature for 2 hours to carry out the polymerization reaction. Then, the temperature inside the flask was further raised to 90 ° C. and maintained for 2 hours to complete the polymerization. By doing so, an aqueous dispersion containing the oil-absorptive cross-linked polymer (1) having an average particle diameter of 30 μm (resin content 25% by weight)
I got

Also, 5 parts of a substantially water-insoluble calcium stearate fine powder (average particle size 8 μm) was added to an aqueous solution prepared by dissolving 1.5 parts of the polyoxyethylene alkyl ether in 150 parts of water, and added at 300 rpm. The mixture was stirred under the conditions to obtain an aqueous dispersion of calcium stearate. Then, 60 parts of an aqueous dispersion containing the oil-absorptive cross-linked polymer (1) obtained by the previous polymerization was gradually added and stirring was continued for 10 minutes to obtain an aggregate composed of the oil-absorptive cross-linked polymer (1) and calcium stearate. Got The aggregate is filtered off and dried at 80 ° C. to obtain a water-dissolved oil absorbent (1) composed of 15 parts of the oil-absorbing crosslinked polymer (1) and 5 parts of calcium stearate and having an average particle diameter of 3 mm. Obtained.

[0037]

Example 2 Hexadecyl methacrylate (SP value: 7.8) 49.93 as the monomer (A) in Example 1.
0 part and N-octyl methacrylamide (SP value:
8.6) 49.930 parts, divinylbenzene O.V. as the crosslinkable monomer (B). By the same method as in Example 1 except that 140 parts were used instead and the number of revolutions was changed to 200 rpm, an aqueous dispersion containing the oil-absorbing crosslinked polymer (2) having an average particle diameter of 300 μm (resin content 25 wt. %) Was obtained.

Further, 5 parts of the same fine powder of calcium stearate as used in Example 1 was added to an aqueous solution prepared by dissolving 1.5 parts of the polyoxyethylene alkyl ether in 150 parts of water and stirred under the condition of 300 rpm. An aqueous dispersion of calcium stearate was obtained. Then, 180 parts of an aqueous dispersion containing the oil-absorbing crosslinked polymer (2) was gradually added and stirring was continued for 10 minutes to obtain an aggregate containing the oil-absorbent crosslinked polymer (2) and calcium stearate. The agglomerates were filtered off, dried at 80 ° C., and then pulverized with a colloid mill to give a dissolved oil in water consisting of 45 parts of the oil-absorbing crosslinked polymer (2) and 5 parts of calcium stearate and having an average particle size of 500 μm. An absorbent (2) was obtained.

[0039]

Example 3 Dodecyl acrylate (SP value: 7.9) 54.1 as a monomer (A) in an aqueous solution prepared by dissolving 3 parts of the polyoxyethylene alkyl ether in 300 parts of water.
53 parts and N, N-dioctyl acrylamide (SP
Value: 8.2) 36.102 parts, polypropylene glycol dimethacrylate (molecular weight 4000) 9.745 parts as the crosslinkable monomer (B), and 2,2 as the polymerization initiator.
′ -Azobisisobutyronitrile O. A solution consisting of 5 parts was added and mixed with a homomixer at 10,000 rpm for 10 minutes to obtain an aqueous dispersion of a monomer.

Then, an aqueous dispersion of the above monomer was charged into a 500 ml flask equipped with a thermometer, a stirrer, a gas introduction tube and a reflux condenser, and the inside of the flask was replaced with nitrogen while vigorously stirring under the conditions of 400 rpm. did. Subsequently, the temperature inside the flask was raised to 70 ° C. under a nitrogen stream, the polymerization temperature was maintained for 2 hours to carry out the polymerization reaction, and then the temperature was further raised to 90 ° C. to complete the polymerization, and the oil absorption with an average particle diameter of 5 μm was obtained. An aqueous dispersion (resin pure content: 25% by weight) containing the crosslinkable polymer (3) was obtained.

Fine powder of zinc caprylate (average particle size 6 μm) which is substantially insoluble in water in an aqueous solution prepared by dissolving 1.5 parts of the polyoxyethylene alkyl ether in 150 parts of water.
m) 5 parts were added, and the mixture was stirred under the condition of 300 rpm to obtain an aqueous dispersion of zinc caprylate. Then, 30 parts of an aqueous dispersion containing the oil-absorbent crosslinked polymer (3) was gradually added and stirring was continued for 10 minutes to obtain an aggregate composed of the oil-absorbent crosslinked polymer (3) and zinc caprylate. Further, the aggregate is filtered off to 80
Oil-absorbing crosslinked polymer (3) by drying at ℃
Average particle size 3 consisting of 7.5 parts and 5 parts of zinc caprylate
An in-water dissolved oil absorbent (3) consisting of mm particles was obtained.

[0042]

Example 4 99.823 parts of dodecyl acrylate (SP value: 7.9) as the monomer (A) in Example 1,
As the crosslinkable monomer (B), ethylene glycol diacrylate O. By the same method as in Example 1 except that 177 parts was used instead, an aqueous dispersion containing the oil-absorbing crosslinked polymer (4) having an average particle diameter of 30 μm (resin pure content: 25% by weight) was obtained.

Further, to an aqueous solution prepared by dissolving 1.5 parts of the polyoxyethylene alkyl ether in 150 parts of water was added 5 parts of a substantially water-insoluble fine powder of aluminum stearate (average particle size 5 μm), and 300 rpm. The mixture was stirred under the conditions described above to obtain an aqueous dispersion of aluminum stearate.
Then, 60 parts of an aqueous dispersion containing the oil-absorbent crosslinked polymer (4) was gradually added and stirring was continued for 10 minutes to obtain an aggregate composed of the oil-absorbent crosslinked polymer (4) and aluminum stearate. Further, this agglomerate is filtered off and dried at 80 ° C. to obtain a water-dissolved oil absorbent (comprising 15 parts of oil-absorbing crosslinked polymer (4) and 5 parts of aluminum stearate and having an average particle diameter of 3 mm in water ( 4) was obtained.

[0044]

Example 5 In Example 1, t- was used as the monomer (A).
Butylstyrene (SP value: 7.9) 54.881 parts and 1-decene (SP value: 7.0) 44.903 parts, divinylbenzene O.C. By the same method as in Example 1 except that 216 parts was used instead, an aqueous dispersion (resin content 25% by weight) containing the oil-absorbent crosslinked polymer (5) was obtained. Then, the resin component was separated from the aqueous dispersion by filtration, dried, and pulverized with a colloid mill to obtain a granular substance having an average particle diameter of 5 μm, which was composed of the oil-absorbent crosslinked polymer (5).

Further, 75 parts of the granular material (average particle size 5 μm) of the oil-absorbent crosslinked polymer (5) and 25 parts of the same fine aluminum stearate powder as used in Example 4 were mixed using a colloid mill. -By granulation, a water-dissolved oil absorbent (5) consisting of particulate matter having an average particle size of 300 µm was obtained.

[0046]

Example 6 Nonylphenyl acrylate (SP value: 8.3) 74.79 as the monomer (A) in Example 1.
3 parts and hydroxyethyl acrylate (SP value: 1
0.3) The same method as in Example 1 except that 24.931 parts was used instead and the amount of 1,6-hexanediol diacrylate as the crosslinkable monomer (B) was changed to 0.276 parts. Thus, an aqueous dispersion (resin content of 25% by weight) containing the oil-absorbent crosslinked polymer (6) having an average particle diameter of 30 μm was obtained.

Further, 5 parts of barium behenate fine powder (average particle size 8 μm), which is substantially insoluble in water, was added to an aqueous solution in which 1.5 parts of the polyoxyethylene alkyl ether was dissolved in 150 parts of water, and 300 rpm was added. The mixture was stirred under the conditions described above to obtain an aqueous dispersion of barium behenate. Then, 60 parts of an aqueous dispersion containing the oil-absorbing crosslinked polymer (6) was gradually added and stirring was continued for 10 minutes to obtain an aggregate consisting of the oil-absorbing crosslinked polymer (6) and barium behenate. Further, this agglomerate is filtered off and dried at 80 ° C. to obtain a water-dissolved oil absorbent (comprising 15 parts of oil-absorbing cross-linked polymer (6) and 5 parts of barium behenate and having an average particle diameter of 3 mm ( 6)
I got

[0048]

Example 7 In Example 1, 99.811 parts of vinyl laurate (SP value: 7.9) as the monomer (A) and trimethylolpropane triacrylate O.V. as the crosslinkable monomer (B). Example 1 except that 187 parts were used instead.
By a method similar to the above, an aqueous dispersion (resin content 25% by weight) containing the oil-absorbent crosslinked polymer (7) having an average particle diameter of 30 μm was obtained.

Further, 5 parts of the same fine powder of aluminum stearate as used in Example 4 was added to an aqueous solution prepared by dissolving 1.5 parts of the polyoxyethylene alkyl ether in 150 parts of water, and added under the condition of 300 rpm. By stirring, an aqueous dispersion of aluminum stearate was obtained. Then, 60 parts of an aqueous dispersion containing the oil-absorptive cross-linked polymer (7) was gradually added,
Stirring was continued for a minute to obtain an aggregate composed of the oil-absorbent crosslinked polymer (7) and aluminum stearate. Further, this agglomerate was filtered off and dried at 80 ° C. to obtain 15 parts of the oil-absorbing crosslinked polymer (7) and 5 parts of aluminum stearate.
To obtain an oil-in-water-dissolved oil absorbent (7) consisting of particles having an average particle diameter of 3 mm.

[0050]

Comparative Example 1 An average particle diameter of 30 μm was obtained in the same manner as in Example 4, except that the amount of dodecyl acrylate was changed to 84.956 parts and the amount of ethylene glycol diacrylate was changed to 15.044 parts. An aqueous dispersion containing the comparative polymer (1) was obtained. Using this aqueous dispersion and aluminum stearate, a comparative absorbent consisting of 15 parts of comparative polymer (1) and 5 parts of aluminum stearate and having a mean particle size of 3 mm and using the same method as in Example 4 (1 ) Got.

[0051]

Comparative Example 2 Dodecyl acrylate 9 in Example 4
Instead of the monomer (A) consisting of 9.823 parts, 39.854 parts of dodecyl acrylate and methacrylic acid (SP
Value: 10.1) 59.780 parts were used, and Comparative Polymer (2) having an average particle size of 30 μm was prepared in the same manner as in Example 4 except that the amount of ethylene glycol diacrylate was changed to 0.366 parts. An aqueous dispersion containing it was obtained. This aqueous dispersion and aluminum stearate were used in the same manner as in Example 4 in the same manner as in Example 4 to prepare a comparative absorbent (2) composed of 15 parts of the comparative polymer (2) and 5 parts of aluminum stearate and having a particle size of 3 mm. ) Got.

[0052]

Comparative Example 3 An aqueous dispersion containing the comparative polymer (3) having an average particle size of 30 μm was obtained by the same method as in Example 4 except that the crosslinkable monomer (B) was not used. It was
This aqueous dispersion and aluminum stearate were used in the same manner as in Example 4 in the same manner as in Example 4 to prepare a comparative absorbent (3) consisting of 15 parts of comparative polymer (3) and 5 parts of aluminum stearate and having a mean particle diameter of 3 mm. ) Got.

[0053]

Comparative Example 4 1 part of the same fine powder of aluminum stearate as used in Example 4 was added to an aqueous solution prepared by dissolving 1.5 parts of the polyoxyethylene alkyl ether in 150 parts of water, and the mixture was added under the condition of 300 rpm. By stirring, an aqueous dispersion of aluminum stearate was obtained. Then, an aqueous dispersion 40 containing the oil-absorptive crosslinked polymer (4) obtained by the polymerization in Example 4 was obtained.
0 part was gradually added and stirring was continued for 10 minutes to obtain an aggregate consisting of the oil-absorbing crosslinked polymer (4) and aluminum stearate. Further, this agglomerate is filtered off, pulverized with a colloid mill and dried at 80 ° C. to obtain 100 parts of the oil-absorbing crosslinked polymer (4) and 1 part of aluminum stearate.
Comparative absorbent (4) was obtained which was composed of granules and had an average particle size of 7 mm.

[0054]

Comparative Example 5 5 parts of the same fine powder of aluminum stearate as used in Example 4 was added to an aqueous solution prepared by dissolving 1.5 parts of the polyoxyethylene alkyl ether in 150 parts of water, and added under the condition of 300 rpm. By stirring, an aqueous dispersion of aluminum stearate was obtained. Then, 8 parts of an aqueous dispersion containing the oil-absorbing crosslinked polymer (4) obtained in Example 4 was gradually added and stirring was continued for 10 minutes to agglomerate the oil-absorbing crosslinked polymer (4) and aluminum stearate. I got a thing. Further, the aggregate is filtered and dried at 80 ° C. to obtain a comparative absorbent (5) consisting of 2 parts of the oil-absorbing crosslinked polymer (4) and 5 parts of aluminum stearate and having an average particle diameter of 3 mm. Got

[0055]

Example 8 300 ml of pure water and 0.33 g of trichloroethylene were charged into a 300 ml Erlenmeyer flask with a stopper, and the mixture was stirred for 4 hours to prepare a saturated aqueous solution of trichlorethylene. Then, in this aqueous solution as an absorbent, Example 1
In water-dissolved oil absorbents (1) to (7) obtained in Comparative Examples 1 to 5, comparative absorbents (1) to (5) obtained in Comparative Examples 1 to 5 and granular activated carbon (average particle size 1.5 mm, total Pore volume 0.8c
m ³ / g) of each 0.25 g, and gently stirred with a magnetic stirrer in a constant temperature bath of 25 ° C., and after 5 minutes, the dissolved trichlorethylene concentration in the aqueous solution was measured by gas chromatography, and trichlorethylene of the following formula was calculated. The removal rate was calculated.

Removal rate (%) = {(initial dissolved trichlorethylene concentration-dissolved trichloroethylene concentration 5 minutes after addition of absorbent) / (initial dissolved trichlorethylene concentration)} × 1
The results are shown in Table 1.

[0057]

[Table 1]

[0058]

Industrial Applicability The method for removing dissolved oil in water of the present invention comprises a granular polymer obtained by complexing a crosslinked polymer excellent in selective absorption and retention of oil with an organic acid metal salt that promotes contact between the oil and the crosslinked polymer. The substance is used as an absorbent, and the absorption mechanism does not utilize the adsorption of oil in the pores unlike conventional activated carbon.Therefore, it absorbs water-soluble organic or inorganic substances or is finely divided by colloidal particles. The pores are not blocked and the absorption capacity is not reduced.

Therefore, according to the method for removing dissolved oil in water of the present invention, not only when only slightly soluble or hardly soluble oil in water is dissolved in water, various water-soluble substances other than oil and water-insoluble colloids are used. Even when impurities such as particulates coexist, it is possible to selectively remove only slightly soluble or slightly soluble oil in water in an extremely short time. Furthermore, oil in suspension, which cannot be completely dissolved in water, can be efficiently absorbed and removed. Moreover, when it is used by being packed in a column or the like, even if the oil-absorbing crosslinked polymer absorbs oil and swells, the organic acid metal salt secures a water passage, so that the pressure loss can be reduced.

Therefore, the method for removing dissolved oil in water according to the present invention is extremely effective for removing harmful oil which is slightly soluble or slightly soluble in water from wastewater and sewage, and is used for treating industrial wastewater and domestic wastewater and for removing oil content. It is extremely effective as an advanced purification method for sewage when it is used as tap water such as tap water.

Claims (3)

(57) [Claims] 1. 90 to 99.999% by weight of a monomer (A) having one polymerizable unsaturated group in a molecule whose main component is a monomer having a solubility parameter (SP value) of 9 or less, 0.001 to 10% by weight of a crosslinkable monomer (B) having at least two polymerizable unsaturated groups in the molecule (however, the total amount of the monomers (A) and (B) is 100% by weight).
30 to 99 parts by weight of an oil-absorptive cross-linked polymer (I) obtained by polymerizing a monomer component consisting of and an organic acid metal salt (II) 1 to 70 having a solubility of 1 g or less in 100 g of water at 20 ° C.
A method for removing a dissolved oil component in water, which comprises mixing the oil component with water in which the oil component is dissolved and absorbing and retaining the dissolved oil component in the water as a water-soluble oil component absorbent. 2. The monomer (A) has at least one aliphatic hydrocarbon group having 3 to 30 carbon atoms and is alkyl (meth) acrylate, alkylaryl (meth) acrylate, alkyl (meth) acrylamide. , Alkylaryl (meth) acrylamide, fatty acid vinyl ester,
The method for removing dissolved oil in water according to claim 1, which comprises at least one unsaturated compound (a) selected from the group consisting of alkylstyrene and α-olefin as a main component. 3. The method for removing dissolved oil in water according to claim 1, wherein the average particle size of the granular material is in the range of 0.1 to 10 mm.