西班牙专利ES2546703A2 Method for improving rejection rate of reverse osmosis membrane, rejection rate improving agent, and

专利PDF首页>>西班牙专利

专利附录

专利说明

权利要求

类似技术

同族专利

引用文献

法律状态

优先权

专利摘要:
Provided is a method for improving the rejection rate of a RO membrane, whereby it becomes possible to further improve the stability of removal performance (rejection rate) and flux stability (sustainability of stain resistance) of the RO membrane. A method for improving the rejection rate of a RO membrane, involving a step of allowing an aqueous solution containing a polyphenol to pass through the RO membrane, said method being characterized by additionally involving a step of allowing an aqueous solution containing at least one component selected from the group consisting of a modified polyvinyl alcohol, a polysaccharide having a high molecular weight and a polyamino acid to pass through the RO membrane. Preferably, the method additionally involves a step of allowing an aqueous solution containing an organic compound having an amino group and having a molecular weight of 1000 or less to pass through the RO membrane.
公开号:ES2546703A2
申请号:ES201590070
申请日:2013-12-18
公开日:2015-09-25
发明作者:Kunihiro Hayakawa；Takahiro Kawakatsu
申请人:Kurita Water Industries Ltd；
IPC主号:

专利说明:

Procedure for improving the rejection rate of reverse osmosis membranes,agent for improving the rejection rate and reverse osmosis membrane5Invention Sector
The present invention relates to a process for improving the rejection rate (rejection rate in a salt) of a reverse osmosis membrane (RO membrane), and in
In particular, it refers to a procedure in which a degraded RO membrane is restored to effectively improve its rejection rate. The present invention also relates to an RO membrane treated by a rejection rate improvement treatment, using the present method for improving the rejection rate of an RO membrane and also refers to an agent for improving the rejection rejection rate at
15 use for this procedure.
Background of the invention
RO membranes have been used in plants for the preparation of water with ultra
20 purity, wastewater recovery plants, seawater desalination plants and the like, and through a treatment using an RO membrane, organic substances, inorganic substances and the like can be largely eliminated of the water. However, given the influences of oxidizing materials and / or reducing materials present in water, acid / alkali cleaning, degradation by
On aging and others, the rejection rate of an RO membrane decreases gradually and as a result the quality of the water that passes through permeation (treated water) cannot be obtained in some cases. In addition, the removal performance can be degraded in some cases due to unexpected problems and the rejection rate of an RO membrane as a finished product may not meet the level required in some cases.
30 In a water treatment system, in order to prevent the spread of sludge in the system, sodium hypochlorite additives or the like are used in many cases. Since chlorine is a strongly oxidizing agent, when an aqueous solution is supplied to an RO membrane, so that it is not sufficiently removed by reduction, the
The residual chlorine, the chlorine and the RO membrane make contact with each other and the RO membrane degrades accordingly.

To decompose the residual chlorine, although a reducing agent, such as sodium bisulfite, can be added, in many cases, in a reducing medium in which an excess of sodium bisulfite is added, when a heavy metal is also present such as Cu , Co,
5 Mn and / or Fe, the membrane degrades (patent literature 1, non-patent literature 1).
As a procedure for improving the rejection rate of a permeation membrane, such as an RO membrane, the following procedures have been proposed.
(1) A procedure in which the rejection rate is improved by adhering a high molecular weight anionic or cationic compound to the membrane surface (patent literature 2).
15 (2) A procedure in which the rejection rate of a nanofiltration membrane or RO membrane is improved by adhering a compound having a poly (alkylene glycol) chain on the surface of the membrane (patent literature 3).
(3) A procedure in which the salt rejection rate is improved by adhering a tannic acid or similar to a degraded membrane (non-patent literature 2).
However, according to the procedures described above, the problem has arisen that since the reduction in permeation flow (flow) is large, even if the rejection rate is restored, the flow of
Permeation decreases by 20% or more from that obtained before treatment in some cases or the problem appears that a severely degraded membrane is difficult to restore sufficiently.
As a procedure to overcome the previous problems of related techniques, the
The current applicant has already proposed a procedure for improving the rejection rate characterized in that an aqueous solution containing a first organic compound with a molecular weight less than 200, a second organic compound having a molecular weight of 200 to less of 500 and a third organic compound having a molecular weight of 500 or more is passed through an RO membrane (bibliography of
35 patent 4).

However, in the process disclosed in patent literature 4 for the improvement of the rejection rate using a polyphenol, such as tannic acid, as the third organic compound having a molecular weight of 500 or more, it is presented a problem due to the fact that the rejection rate and flow gradually decrease due to the quality of the
5 raw water; therefore, it has been desired to achieve a procedure that improvesadditionally the stability of the elimination performance (rejection rate) and theflow stability (sustainability of pollution resistance).
Bibliographic list
10 Patent Bibliography 1: Japanese Patent Publication 7-308671 A Patent Bibliography 2: Japanese Patent Publication 2006-110520 A Patent Bibliography 3: Japanese Patent Publication 2007-289922 A Patent Bibliography 4: Japanese Patent Publication 2012 -187469 A
15 Non-patent bibliography
Non-patent bibliography 1: Fujiwara and others, desalination, Vol. 96 (1994), 431-439. Non-patent bibliography 2: Satoh and Tamura, KAGAKU KOGAKU RONBUNSHU, Vol. 34
20 (2008), 293-498.
Summary of the Invention
The present invention is intended to disclose a method for improving the
The rejection rate of an RO membrane, in which the stability of the rejection performance (rejection rate) and the stability of the flow (sustainability of the resistance to contamination) are further improved and an agent for the improvement of the rejection rate for the procedure described. Additionally, the present invention is also intended to provide an RO membrane treated by a
30 treatment for improving the rejection rate using the procedure for improving the rejection rate of an RO membrane, as described above.
Through intensive research carried out to achieve the aforementioned objectives, current inventors have obtained the following invention.
35 Namely, the reason for the stability of the removal performance by a treatment of

improvement of the rejection rate using a polyphenol is lower, it is believed that the polyphenol is separated by stripping of the RO membrane and, in addition, the reason why the flow stability is lower, it is believed that it is because surface loading properties of a membrane are improved by treating rejection rate improvement, pollutants are likely to adhere to it.
The present inventors have deduced that when a high molecular weight compound is adsorbed or applied as a coating on a polyphenol that is used for a treatment to improve the rejection rate, the polyphenol cannot be stripped off of the membrane and Improves stability of removal performance.
Additionally, the present inventors have also deduced that when a polyvinyl alcohol is used as a high molecular weight compound of the type described, the loading properties of the membrane surface decrease to approximately zero, and stability can be obtained. flow. However, the problem has arisen that a common polyvinyl alcohol has low membrane absorption properties.
Accordingly, since a modified polyvinyl alcohol, which has an ionic group, a poly (alkylene oxide) chain and / or the like, has a high adsorption property on an RO membrane, the present inventors have discovered the use of a modified polyvinyl alcohol. That is, although a carboxyl group and an amino group are present on the surface of the membrane, of a usual RO membrane, these functional groups have a high reactivity with an ionic group and a poly (alkylene oxide) chain has a high adsorption property in the membrane. Therefore, it is believed that when the modified polyvinyl alcohol is used, which has an ionic group, a poly (alkylene oxide) chain and / or the like, greater stability than that of a normal polyvinyl alcohol can be obtained.
Since a high molecular weight polysaccharide has as its own characteristic a thickening function to increase the viscosity of an aqueous solution, this thickening function increases the adsorption stability of a polyphenol, which is a component for improving the rate of rejection for an RO membrane.
It is believed that since a poly (amino acid) has a cationic property and an anionic property, by interaction with a carboxy group and an amino group present on the surface

of an RO membrane and, in addition, by the interaction with a polyphenol, an effect of improving the adsorption property is obtained.
The present invention has been carried out based on the discovery indicated above and a summary thereof is indicated below.
[1] A method for improving the rejection rate of a reverse osmosis membrane, the method comprising a step in which an aqueous solution containing a polyphenol is allowed to pass through a reverse osmosis membrane, so that the procedure It further comprises a step to allow an aqueous solution, containing at least one type selected from the group consisting of a modified polyvinyl alcohol, a high molecular weight polysaccharide and a poly (amino acid) to cross the reverse osmosis membrane.
[2] The procedure for improving the rejection rate of a reverse osmosis membrane, according to [1], in which an aqueous solution, containing a polyphenol and, at least, a type selected from the group that It consists of a modified polyvinyl alcohol, a high molecular weight polysaccharide and a poly (amino acid) is passed through the reverse osmosis membrane.
[3] The procedure for improving the rejection rate of a reverse osmosis membrane, according to [1], wherein after passing the aqueous solution containing a polyphenol through the reverse osmosis membrane, The aqueous solution containing at least one type selected from the group consisting of a modified polyvinyl alcohol, a high molecular weight polysaccharide and poly (amino acid) is passed through the reverse osmosis membrane.
[4] The procedure for improving the rejection rate of a reverse osmosis membrane, according to [3], in which the aqueous solution containing at least one type selected from the group consisting of a polyvinyl alcohol modified, a high molecular weight polysaccharide, and a poly (amino acid) contains a polyphenol.
[5] The process for improving the rejection rate of a reverse osmosis membrane, according to any of [1] to [4], further comprising a step of passing an aqueous solution containing an organic compound, which has an amino group with a molecular weight of 1,000 or less across the osmosis membrane

inverse
[6] The method for improving the rejection rate of a reverse osmosis membrane, according to [5], in which an aqueous solution containing at least one polyphenol, a type selected from the group consisting of an alcohol Modified polyvinyl, a high molecular weight polysaccharide and a poly (amino acid) and an organic compound having an amino group and having a molecular compound of 1,000 or less is passed through the reverse osmosis membrane.
[7] The process for improving the rejection rate of a reverse osmosis membrane, according to [5], wherein after passing an aqueous solution containing a polyphenol and an organic compound with an amino group and having a molecular weight of 1,000 or less through the reverse osmosis membrane, an aqueous solution containing at least one type selected from the group consisting of an alcohol is passed through said reverse osmosis membrane modified polyvinyl, a high molecular weight polysaccharide and a poly (amino acid).
[8] The procedure for improving the rejection rate of a reverse osmosis membrane, according to [7], in which the aqueous solution containing at least one type selected from the group consisting of a polyvinyl alcohol Modified, a high molecular weight polysaccharide and a poly (amino acid), contains a polyphenol and an organic compound having an amino group and having a molecular weight of 1,000 or less.
[9] The procedure for improving the rejection rate of a reverse osmosis membrane, according to [1], polyphenol includes a tannic acid.
[10] The method for improving the rejection rate of a reverse osmosis membrane, according to [1], wherein the poly (amino acid) comprises a polylysine.
[11] The method for improving the rejection rate of a reverse osmosis membrane, according to [1], in which the modified polyvinyl alcohol comprises at least one type selected from the group consisting of polyvinyl alcohol cationic modified having a cationic group as a modifying group, an anionic modified polyvinyl alcohol, having an anionic group as a modifying group and a modified polyvinyl alcohol having a poly (alkylene oxide) chain.

[12] The method for improving the rejection rate of a reverse osmosis membrane, according to [1], in which the high molecular weight polysaccharide comprises at least one type selected from the group consisting of Xanthan gum, agar gum, carboxymethyl cellulose and its salts, an alginic acid and its salts, and a chitosan.
[13] The procedure for improving the rejection rate of a reverse osmosis membrane, according to [1], in which the total amount of polyphenol and at least one type selected from the group consisting of polyvinyl alcohol modified, the high molecular weight polysaccharide, and the poly (amino acid) supplied to the reverse osmosis membrane and which is calculated from the concentrations of the aqueous solutions and the amounts thereof that are passed through the Reverse osmosis membrane is adjusted so that the weight ratio of polyphenol to at least one type selected from the group consisting of modified polyvinyl alcohol, high molecular weight polysaccharide and poly (amino acid) is in a range of 1: 0.1 to 5.
[14] The method for improving the rejection rate of a reverse osmosis membrane, according to [5], wherein the organic compound having an amino group and having a molecular weight of 1,000 or less, comprises arginine and / or aspartame.
[15] The procedure for improving the rejection rate of a reverse osmosis membrane, according to [5], in which the total amount of polyphenol and organic compound having an amino group and having a molecular weight 1,000 or less supplied to the reverse osmosis membrane and which is calculated from the concentrations in the aqueous solutions, and the amounts thereof that are passed through the reverse osmosis membrane, is adjusted so that The weight ratio of polyphenol to the organic compound, which has an amino group and has a molecular weight 1,000 or less, is in a range of 1: 0 to 2.
[16] The procedure for improving the rejection rate of a reverse osmosis membrane, according to [1], in which the pressure during the water supply is 0.1 to 0.5 MPa, and the Permeation flow is 0.1 to 1.0 m3 / (m2 · day).
[17] Reverse osmosis membrane treated by the procedure for improving the rejection rate, according to any of [1] to [16].

[18] Agent for the improvement of the rejection rate for a reverse osmosis membrane, whose agent comprises a polyphenol and at least one type selected from the group consisting of a modified polyvinyl alcohol, a high molecular weight polysaccharide and a poly (amino acid).
[19] The agent for improving the rejection rate for a reverse osmosis membrane, according to [18], which further comprises an organic compound having an amino group and having a molecular weight of 1,000 or less.
Advantageous effects of the invention
According to the present invention, when an RO membrane is treated using a polyphenol and at least one type selected from the group consisting of modified polyvinyl alcohol, high molecular weight polysaccharide, and poly (amino acid) (then the compounds they will be designated as "second component for the improvement of the rejection rate" in some cases), the rejection rate of the RO membrane can be efficiently restored and an RO membrane can be obtained in which the stability of the elimination performance (rejection rate and flow stability (sustainability of pollution resistance) is further improved.
An excellent treatment effect can be obtained when an organic compound having an amino group and having a molecular weight of 1,000 or less is also used together (referred to below as "low molecular weight amino compound" in some cases).
According to the present invention, in comparison to the case in which a polyphenol -22- is only adsorbed on a RO -21- membrane, as shown in Figure 1 (a), when the polyphenol -22- and A second component -23- for the improvement of the rejection rate is adsorbed on the RO -21- membrane, as shown in Figure 1 (b), by the interaction of the second component -23- for the improvement of the rejection rate with the RO -21-and / or the polyphenol -22- membrane, the polyphenol -22-is coated and in addition, its adsorption state can be stabilized.
When a low molecular weight amino compound -24-is also used together, as shown in Figure 1 (c), the low molecular weight amino compound -24-restores the degraded parts of the RO membrane - 21-and therefore

The rejection rate can be improved effectively.
Brief description of the drawings
5 Figure 1 comprises explanatory views showing the mechanism of a treatment for improving the rejection rate by means of the present invention.
Figure 2 is a schematic view showing a flat membrane test apparatus used in the examples. In this figure, indications A, B and C must be interpreted
10 according to the following meanings:
A: Test water
B: Water passed through permeation
C: Condensed Water
15 Description of achievements
In the following, embodiments of the present invention will be described in detail.
A method for improving the rejection rate of an RO membrane, according to the present invention is characterized in that a polyphenol (referred to below as "first component for improving the rejection rate" in some cases) and at least one type selected from the group consisting of a modified polyvinyl alcohol, a high molecular weight polysaccharide and a poly (amino acid) each
25 one of which is a second component for the improvement of the rejection rate, are used together (then, the first component for improving the rejection rate and the second component for improving the rejection rate are designated, each of them simply "component for the improvement of the rejection rate" in some cases), and also an organic compound (low weight amino compound
Molecular) having an amino group and having a molecular weight of 1,000 or less, is also preferably used together.
[RO membrane]
35 An RO membrane is a liquid separation membrane that allows a solvent to pass through it and rejects a solute when a higher pressure than the

Unlike the osmotic pressure between solutions separated by an interposed membrane, it is applied to the high concentration side. As the membrane structure of the RO membrane, for example, there can be mentioned a high molecular weight membrane, such as an asymmetric membrane or a composite membrane. In the present invention as a RO membrane material to be treated for the improvement of the rejection rate, for example, a polyamide-based material, such as an aromatic polyamide, an aliphatic polyamide or a composite material disposed between those and a cellulose based material, such as cellulose acetate. Among those mentioned above, although a polyamide-based RO membrane using an aromatic polyamide as a dense layer, can be mentioned as an example, a polyamide-based nanofiltration membrane can also be mentioned as an object. That is, an RO membrane that is used as a treatment object of the present invention indicates a broadly RO membrane, including a nanofiltration membrane.
In particular, the present invention is preferably applied to an RO membrane that generates a carbonyl group when a C-N bond thereof is segmented by degradation.
When the salt rejection rate of an RO membrane that has not yet been treated by the rejection rate improvement treatment is 90% or less, the process of the present invention is preferably applicable thereto.
One embodiment of the RO membrane module is not particularly limited, and there can be mentioned, for example, a tubular membrane module, a flat membrane module, a spiral membrane module and a hollow fiber membrane module.
[Polyphenol]
As the polyphenol used in the present invention, there can be mentioned a polyphenol having a molecular weight of 500 or more, particularly 500 to 500,000, and more particularly 500 to 50,000 being preferable since it effectively covers the surface of an RO membrane being fixed thereto, and for example, tannic acid, lignin and a derivative of lignin. As tannic acid, a tannic acid may be mentioned, such as Japanese gill, gall nut, quebracho or mimosa. These polyphenols can be used alone or at least two types of them can be used in combination.

[Second component to improve the rejection rate]
As a second component for the improvement of the rejection rate, the following: modified polyvinyl alcohol, high molecular weight polysaccharide and poly (amino acid) can be used alone or at least two types of them can be used in combination.
<Modified Polyvinyl Alcohol>
The modified polyvinyl alcohol is formed by units of vinyl alcohol and units in which modifying groups are attached and may also include vinyl acetate units, in some cases.
The molar fraction of the units to which the modifying groups in the modified polyvinyl alcohol are attached is preferably from 0.1 to 50 percent per mole, more preferably from 0.3 to 40 percent per mole and particularly preferably from 0.5 to 30 percent per mole. When the molar fraction of the units to which the modifying groups are attached is smaller than this range, an effect of improving the adsorption characteristics to an RO membrane generated by the incorporation of the modifying groups cannot be obtained sufficiently, and on the other hand, when the molar fraction is high, the molar fraction of the vinyl alcohol units decreases relatively, and as a result the effect of improving the rejection rate is reduced.
The molar fraction of the units of vinyl alcohol in the modified polyvinyl alcohol is preferably 50 to 99.9 percent per mole, more preferably between 60 to 99.7 percent per mole and, especially preferably 70 to 99, 5% per mole When the molar fraction of the vinyl alcohol units is smaller than this range, since the number of hydroxyl groups of the modified polyvinyl alcohol decreases, a sufficient effect of improving the rejection rate cannot be obtained. In contrast, when the molar fraction is high, the molar fraction of the units to which the modifying groups bind decreases relatively and, as a result, the effect of improving the adsorption property on an RO membrane generated by the incorporation of the Modifying groups cannot be obtained sufficiently in some cases.
The molar fraction of the vinyl acetate units in the modified polyvinyl alcohol is preferably 0 to 20 percent per mole, more preferably 0 to 10 percent per mole and particularly preferably 0 to 5 percent per mole .

As an indicator index of the characteristics of a polyvinyl alcohol, the degree of saponification has been used. The degree of saponification is obtained by dividing the molar fraction of the vinyl alcohol units by the total molar fraction of the vinyl alcohol units and vinyl acetate units. The degree of saponification of the modified polyvinyl alcohol of the present invention is preferably 80% or more, particularly preferably 85% or more, and more particularly 95% or more. When the degree of saponification is less than 80%, since the number of hydroxyl groups decreases, the hydrophilic properties degrade and, probably, the sufficient effect of improving the rejection rate and flow stability cannot be obtained.
While the degree of polymerization of polyvinyl alcohol, that is, the number of units described, is not particularly limited, 20 to 20,000 is preferable. when the degree of polymerization is excessively low, the adsorption characteristics to a membrane are degraded and when the degree of polymerization is excessively high, this is not preferable since the decrease in flow of an RO membrane caused by the improvement treatment of The rejection rate.
As the modified polyvinyl alcohol modifying group, a group containing either an ionic group or a poly (alkylene oxide) group (group having a polyoxyalkylene oxide chain) or a group containing both is preferable. As a modified polyvinyl alcohol, when a compound having a quaternary ammonium salt is selected, interaction with a carboxy group and / or a polyphenol on the surface of an RO membrane can be expected. As the modified polyvinyl alcohol, when a compound having a poly (ethylene oxide) group is selected, since the poly (ethylene oxide) chain is adsorbed on a polyamide-based RO membrane, interaction with the RO membrane.
As a cationic polyvinyl alcohol having a cationic group as a modifying group, a compound produced is preferably such that, after a cationic monomer and vinyl ester, such as vinyl acetate, they are copolymerized with each other, carrying out their hydrolysis (saponification).
As a cationic monomer, a monomer having -NH2, -NHR, -NRR ', -NH3 +, -NH2R, -NHRR' + or -NRR'R '' + (R, R 'and R' 'each represents a hydrocarbon residue thereof), and in particular, for example, a diallyl dimethyl ammonium salt, an acrylate or a

methacrylate having an ammonium group, an N-substituted methacrylamide, vinylpyridine, a quaternary ammonium salt of vinylpyridine and vinylimidazole.
As commercially available products of cationic polyvinyl alcohol, there may be mentioned, for example, "C-506" and "CM-318" (both manufactured by Kuraray Co., Ltd.), and "GOHSEFIMER K-210" (manufactured by The Nippon Synthetic Chemical Industry Co., Ltd.).
As an anionic group of an anionic polyvinyl alcohol, which has an anionic group as a modifying group, there can be mentioned, for example, a carboxyl group, a sulfonic acid group or a phosphoric acid group and, taking into account the economic and economic aspects of ease of fabrication a carbonyl group and a sulfonic acid group are preferable.
As a process for the manufacture of a modified polyvinyl alcohol incorporating a carboxy group in a polyvinyl alcohol, a process may be mentioned in which it is copolymerized with a vinyl ester, an unsaturated basic acid, an unsaturated dibasic acid, an anhydride of the same or an ester or a salt of said acids, such as vinyl acetate and comprising acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, maleic anhydride, or itaconic anhydride, being copolymerized to form a copolymer, and then its saponification is carried out.
When a vinyl ester copolymer mentioned above with acrylonitrile, methacrylonitrile, acrylamide, methacrylamide or the like is saponified, a vinyl alcohol with a modified carbonyl group can also be obtained.
As a procedure using graft polymerization after mentioning a procedure in which saponification is carried out after a polyvinyl alcohol or a polyvinyl ester, such as a polyvinyl alcohol, it is graft polymerized with an acrylonitrile, acylamide or Similary. As a process that uses a chemical reaction of a polyvinyl alcohol, by a hemiesterification reaction, in which a dibasic acid, such as maleic acid, fumaric acid, phthalic acid, malonic acid, sulfinic acid, oxalic acid, adipic acid, or a Anhydrous thereof is reacted with a polyvinyl alcohol a carboxyl group can be incorporated into a polyvinyl alcohol.
When a sulphonic acid group is incorporated into a polyvinyl alcohol, a process in which a polyvinyl alcohol is reacted with sulfonic acid can be used.

concentrated. A polyvinyl alcohol modified by a group of sulfonic acid can be obtained by a process in which, after copolymerizing vinyl acetate with ethylene sulfonic acid, allyl sulfonic acid, metalyl sulfonic acid, 2-acrylamide-2-methylpropan sulfonic acid, or an ester or a salt thereof, saponification is carried out.
As commercially available anionic polyvinyl alcohol, there may be mentioned, for example, "KL-118", "KL-318", "KM-118", "KM-618", and "SK-5102" (all of them manufactured by Kuraray Co., Ltd.); and "GOHSENAL T-330", "GOHSENAL T-330H", "GOHSENAL T-350", "GOHSERAN L-3266", "GOHSERAN L-0301", "GOHSERAN L-0302" and "GOHSERAN CKS-50" ( all of them manufactured by The Nippon Synthetic Chemical Industry Co., Ltd.).
As the poly (alkylene oxide) chain of a modified polyvinyl alcohol having a poly (alkylene oxide) chain, a poly (alkylene oxide) chain in which the number of carbon atoms of the alkylene group is preferable is preferred. from 2 to 4, such as poly (ethylene oxide), poly (propylene oxide) or a poly (butylene oxide), is preferable, and a poly (ethylene oxide) is more preferable. The number of repetitive units of an alkylene oxide is preferably from 2 to 300 and particularly preferably from 10 to 100. When the number of repetitive units described above is excessively small, the effect of improving the characteristics cannot be sufficiently obtained. of adsorption to a RO membrane by a poly (alkylene oxide) chain, and when the number described above is excessively large, this is not preferable since the decrease in flow of an RO membrane caused by the treatment for improving the rejection rate
A modified polyvinyl alcohol, having a poly (alkylene oxide) chain, as described above, can be obtained by a known synthetic process. In addition, a commercially available product, such as "ECOMATI WO-320N" or "ECOMATI WO-320R" manufactured by The Nippon Synthetic Chemical Industry Co., Ltd. can also be used.
As a method of synthesizing a modified polyvinyl alcohol having a poly (alkylene oxide) chain, although a process is preferred in which after a monomer having a polyvinyl alcohol chain is copolymerized with vinyl acetate, acetate partially or completely saponified vinyl to form vinyl alcohol, other synthetic processes can also be used.

As a monomer having a poly (alkylene oxide) chain, as described above, for example, there may be mentioned a poly (ethylene oxide) monovinyl ether, a poly (ethylene oxide) monoalyl ether, a poly ( ethylene glycol) monomethacrylate, a poly (ethylene glycol) monoacrylate, a poly (propylene glycol) monomethacrylate, a poly (propylene glycol) monoacrylate, a poly (ethylene glycol) -poly (propylene glycol) monomethacrylate, a poly (ethylene glycol) poly (propylene glycol) monoacrylate, a poly (ethylene glycol tetramethylene glycol) monomethacrylate, a poly (ethylene glycol tetramethylene glycol) monoacrylate, a poly (ethylene glycol propylene glycol) monomethacrylate or a methoxy poly (ethylene glycol) propylene glycol) monoacrylate. The compounds mentioned can be used alone, or at least two types of them can be used in combination.
<High molecular weight polysaccharide>
As a high molecular weight polysaccharide, a high molecular weight polysaccharide can be used which is particularly used as a food additive, which has a molecular weight of 10,000 or more, and which has a high adsorption characteristic to an RO membrane. The upper limit of the molecular weight of the high molecular weight polysaccharide is not particularly limited, and any water soluble high molecular weight polysaccharide can be used. As the high molecular weight polysaccharide of the type described above, for example, xanthan gum (molecular weight may be mentioned
2,000,000 or more), gum agar (molecular weight: 200,000 to 300,000), a carboxymethyl cellulose and its salts (molecular weight: 50,000 or more), alginic acid and its salts (molecular weight: 10,000 or more) and chitosan (weight molecular: 10,000 or more).
These high molecular weight polysaccharides have generally been used as a thickening agent and preferably have adsorption properties to an RO membrane. That is, for example, when an aqueous solution containing xanthan gum with a concentration of 1 mg / L has been passed through a RO membrane based on aromatic polyamide (ES20) manufactured by Nitto Denko Corporation at a pressure of 0, 75 MPa, the permeation flow decreased from 0.9 m3 / (m2 · day) to 0.5 m3 / (m2 · day) for 7 days. The reason for this is believed that, since the adsorption characteristics of an xanthan gum to the RO membrane are high, its permeation flow decreases. In addition, in the case of an agar rubber using the same test described, the permeation flow decreases from 0.9 m3 / (m2 · day) to 0.3 m3 / (m2 · day) for 7 days. As described above, it follows that a compound that decreases the permeation flow

of a RO membrane by water supply, it has high adsorption properties to the RO membrane.
These high molecular weight polysaccharides can be used alone or at least two types of them can be used in combination.
<Poly (amino acid)>
As a poly (amino acid), for example, a polylysine, polyglycine, and a poly (glutamic acid) can be used, all of which are a type of amino acid polymer, having a molecular weight of 1,000 to 1,000,000. In addition, a polymer formed by at least two types of amino acids can also be used. In particular, a polylysine, a polyarginine, a polyhistidine are preferably used, each of which is a polymer of a basic amino acid. In particular, a polylysine is preferable to achieve a strong electrostatic interaction with a polyphenol, and to be able to obtain a significant effect of improving the rejection rate together with a polyphenol. The poly (amino acids) described in the foregoing can be used alone, or at least two types of them can be used in combination.
[Low molecular weight amino compound]
In the present invention, in addition to the polyphenol and the second component for improving the rejection rate, the treatment for improving the rejection rate can also be carried out by additional use of an organic compound (low molecular weight amino compound ) having an amino group and having a molecular weight of 1,000 or less, and since the low molecular weight amino compound is used together, the effect of improving the rejection rate can be further improved.
As the low molecular weight amino compound, a compound having a molecular weight of 1,000 or less, and particularly, a compound having a molecular weight of less than 500, such as a compound having a molecular weight of 70 to 300, is preferable, with a restoration effect of the degraded part of an RO membrane being preferable, and as a low molecular weight amino compound, as described above, the following may be mentioned by way of example. While the following low molecular weight amino acid compounds can be used alone or, at least two types of them can be used in combination, by increasing the

Number of types in operation is likely to be complicated.
An aromatic amino compound: a compound that has a benzene skeleton and aamino group, such as aniline (molecular weight: 93) or diaminobenzene (molecular weight:5 108).
Aromatic amino carboxylic acid compound: a compound having a benzene backbone, at least two amino groups and, at least, a carboxyl group, the number of which is less than the number of amino groups, such as 3,5-diaminobenzoic acid acid
3,4-Diaminobenzoic acid (molecular weight: 152) or 2,4,6-triaminobenzoic acid (molecular weight: 167).
An aliphatic amino acid: a compound having a linear hydrocarbon group with about 1 to 20 carbon atoms and at least one amino group, such as
Methylamine (molecular weight: 31), ethylamine (molecular weight: 45), or octylamine (molecular weight: 129), or a compound having a branched hydrocarbon group with about 1 to 20 carbon atoms and, at least, one group amino, such as aminopentane (molecular weight: 87), or 2-methyl-1,8-octanediamine (molecular weight: 143).
An aliphatic amino alcohol: a compound having a linear or branched hydrocarbon group with 1 to 20 carbon atoms to which an amino group and a hydroxyl group, such as 4-amino-2-methyl-1-butanol, have been attached (weight molecular: 103).
A heterocyclic amino compound: a compound having a heterocyclic ring and an amino group, such as tetrahydrofurfurylamine (molecular weight: 101).
An amino acid compound: a basic amino acid compound, such as arginine (molecular weight: 174) or lysine (molecular weight: 146), an amino acid compound having an amide group, such as asparagine (molecular weight: 132) or glutamine (molecular weight : 146), or an amino compound, such as glycine (molecular weight: 75) or phenylalanine (molecular weight: 165).
An ethylenediamine: a polyethyleneamine, such as ethylenediamine (molecular weight: 60), diethylenetriamine (molecular weight: 103), triethylenetetramine (molecular weight: 146), tetraethylenepentamine (molecular weight: 189) or pentaethylenehexamine (molecular weight: 232).
35 Aspartame (molecular weight: 294), carnosine (molecular weight: 226), Nα- (L-tyrosyl) -L-arginine

(molecular weight: 336), or pyrimidine-2,4,5,6-tetramine (molecular weight: 140).
Each of these low molecular weight amino compounds has a high water solubility, being able to pass through an RO membrane in the form of a stable aqueous solution, is attached to the RO membrane by a reaction with a carboxyl group thereof, forms a salt insoluble, and is capable of blocking holes generated by membrane degradation.
[Rejection Rate Improvement Component Concentration]
In the present invention, as regards the concentration in an aqueous solution of polyphenol, the second component for improving the rejection rate, and the low molecular weight amino compound described above, when only one of them is contained, its concentration is preferably it adjusts from 1.0 to 5,000 mg / L or particularly from 1.0 to 2,000 mg / L, and when at least two types thereof are contained, the total concentration is also preferably adjusted to that which has been previously described. When the concentration described above is excessively low, this is not preferable since a long period of treatment is required. In addition, when this concentration is excessively high, adsorption takes place forming a multi-layered structure on the surface of the membrane, and the amount of compound that does not reach the degraded part increases, so that recovery efficiency is also degraded.
In order to effectively obtain the effect of the present invention using polyphenol together with the second component for improving the rejection rate, as a total amount supplied to an RO membrane, calculated from the concentration in an aqueous solution and the amount that it is allowed to pass through the RO membrane, polyphenol and the second component of improvement of the rejection rate are preferably used so that the weight ratio of the polyphenol to the second component of improvement of the rejection rate is in a range from 1: 0.1 to 5 and, in particular, in a range of 1: 0.1 to 2.
When the low molecular weight amino compound is used additionally, as a total amount to an RO membrane calculated from the concentration in an aqueous solution and the amount that can pass through the RO membrane, the low amino compound is preferably used molecular weight, so that the weight ratio of polyphenol to the low molecular weight amino compound is in a range of 1: 0 to 2 and, in particular, in a range of 1: 0.1 to 1.

[Treatment Process]
Before the treatment of improvement of the rejection rate by the present invention,
5 preferably carry out a cleaning treatment of an RO membrane. After having cleaned the RO membrane, without carrying out any additional treatment, the treatment for improving the rejection rate by means of the present invention is preferably carried out by circulation an aqueous solution containing the rate improvement component of rejection using a cleaning machine.
In the present invention, when the polyphenol and the second component for improving the rejection rate are used in conjunction with the low molecular weight amino compound, the order of supply of the polyphenol, the second component for improving the rejection rate, and the low molecular weight amino compound to an RO membrane is not specifically
15 limited, and the treatment of improvement of the rejection rate can be carried out using a type of aqueous solution prepared by collectively adding said compounds to an aqueous solution, or aqueous solutions of the aforementioned compounds can be passed separately to through the RO membrane.
When the treatments are carried out separately from each other, the treatment using the second component of improvement of the rejection rate is preferably carried out at the end. That is, as shown in Figures 1 (b) and (c), the second component for improving the rejection rate covers polyphenol and the low molecular weight amino compound and favors its adsorption stability. Therefore the second
The rejection rate improvement component is adsorbed on an RO membrane before the polyphenol and the low molecular weight amino compound are adsorbed therein, it is not preferable since the adsorption of the polyphenol and the low weight amino compound Molecular can be altered in some cases.
30 As a specific order of supply of the aqueous solutions, the following may be mentioned.
(1) An aqueous solution containing polyphenol and the second component for improving
Rejection rate is passed through an RO membrane. 35
(2) After passing through an RO membrane an aqueous solution that

Contains the polyphenol, an aqueous solution containing the second component for improving the rejection rate is passed through the RO membrane.
(3) After an aqueous solution containing the polyphenol is passed through an RO membrane, an aqueous solution containing the polyphenol and the second component for improving the rejection rate are passed through the RO membrane.
(4) After passing through an RO membrane an aqueous solution containing the polyphenol, the second component for improving the rejection rate and the low molecular weight amino compound.
(5) After an aqueous solution containing the polyphenol and the low molecular weight amino compound is passed through an RO membrane, an aqueous solution containing the second component for improving the rejection rate is passed through the RO membrane .
(6) After an aqueous solution containing the polyphenol and the low molecular weight amino compound is passed through an RO membrane, and the second component for improving the rejection rate is passed through the RO membrane.
The treatment for improving the rejection rate by means of the present invention can be a treatment in which sequentially added to the water to be supplied or circulated through an RO membrane, chemical agents such as polyphenol and the second component of improvement of the rejection rate, and the treatment can be carried out in such a way that the water to be supplied or circulated through an RO membrane is changed for each component to improve the rejection rate.
When the pressure to pass an aqueous solution containing the rejection rate improvement component through an RO membrane is excessively high, adsorption of the rejection rate improvement component to a part of the RO membrane is facilitated which is not degraded and, as a result, a problem of permeation flow decrease can occur, and when the previous pressure is excessively low, the contact efficiency of the rejection improvement component with a degraded part of the RO membrane decreases, and as a result, the effect of improving the desired rejection rate cannot be obtained in some cases. Bearing in mind that the present invention is preferably carried out without any further treatment after

Since a RO membrane is cleaned by a cleaning machine, the water supply pressure (inlet pressure) during the rejection rate improvement treatment is preferably 0.1 to 0.5 MPa. In comparison to a common functional pressure for the RO membrane, 10% to 150% and in particular 25% to 100% is preferable. Although the permeation flow during the treatment of improvement of the rejection rate refers to the pressure, water temperature, membrane shape, and the like, 0.1 to 1.0 (m3 / m2 · day) is preferable. . The reasons for this are that as in the case described above, when the pressure is excessively high, adsorption to a part of an RO membrane that is not degraded is disadvantageously encouraged, and when the pressure is excessively low, Contact efficiency with a degraded part of the RO membrane degrades.
While treatment times may not be especially limited as long as the times are 1 hour or more, a time between 1 hour and 48 hours is preferable. When the treatment time is less than 1 hour, this is not preferable since the treatment can be terminated before having sufficiently obtained the fixation property of the rejection rate improvement component, and the rate improvement component. rejection adhered to an RO membrane can be removed by peeling in some cases.
The temperature (water temperature) during the treatment is preferably from 10 ° C to 35 ° C. When the water temperature is excessively low, the amount of permeation water decreases, and the contact efficiency between the component for improving the rejection rate and the RO membrane degrades. It is believed that, when the temperature of the water rises excessively, problems can occur in some cases, such as denaturation of the membrane material.
As a tracer, an inorganic electrolyte, such as common salt (NaCl), a neutral organic substance, such as isopropyl alcohol or glucose, and a low molecular weight polymer, such as a poly (maleic acid) can be added to the tracer. treatment water for the improvement of the rejection rate, which is passed through an RO membrane for treatment of improvement of the rejection rate, and by this addition, the degree of membrane restoration can be confirmed by analysis of the degree of permeation of common salt and / or glucose with respect to the water that the RO membrane has permeated.

When the treatment for improving the rejection rate by means of the present invention is carried out in the situation that the water to be treated is supplied for a long period of time and / or in the situation in which the permeation flow decreases by membrane contamination, the treatment of improvement of the rejection rate by means of the present invention is preferably carried out after cleaning by means of a chemical agent, but this cleaning process is not always necessary.
As chemical agent for cleaning by chemical agent, there can be mentioned a cleaning by acid, an inorganic acid, such as hydrochloric acid, nitric acid, or sulfuric acid, or an organic acid, such as citric acid or oxalic acid. In alkali cleaning, there can be mentioned, for example, sodium hydroxide or potassium hydroxide. In general, in acid cleaning, the pH is adjusted to approximately 2, and in alkali cleaning, the pH is adjusted to approximately 12.
RO membranes treated by means of the process of the present invention are effectively applied to water treatments to recover and recycle water with high or low TOC concentration that is discharged from an electronic device in the manufacturing sector, manufacturing sector of semiconductors, and several other industrial or water treatment sectors to prepare water with ultra-purity from industrial water and domestic water and other sectors. While the water to be treated, which is an object of treatment, is not particularly limited, the RO membrane is preferably used for water containing organic substances and is preferably used, for example, for water containing organic substances with a TOC of 0 , 01 to 100 mg / L and preferably, approximately 0.1 to 30 mg / L. As water containing organic substances as described above, although the drainage of an electronic device manufacturing plant, transport machine manufacturing plant, organic synthesis plant, printing and pressing / painting plant can be mentioned, or the like or primary wastewater from the drain described above, water containing organic substances is not especially limited.
Examples
In the following, the present invention will be described in more detail with reference to examples and comparative examples.
In the following examples and comparative examples, the evaluation of

such that by using the flat diaphragm test apparatus shown in Figure 2, after having mounted a degraded RO membrane on it, treatment water was supplied to improve the rejection rate, and passed to through the membrane an aqueous solution of NaCl for performance evaluation.
This flat membrane test apparatus is configured such that a cell -2 with flat membrane is disposed in an intermediate position of a cylindrical container -1-having a lid at a height of its direction to separate the interior of the container into a chamber of raw water -1A-and a chamber -1B-of water that has passed through permeation, said container -1-being placed on a stirrer -3-, supplying water to be treated to chamber -1A-of raw water by means of a pump -4-through a pipe -11-, the interior of the raw water chamber -1A-being stirred simultaneously by rotating a stir bar -5-inside the container -1-, simultaneously recovering water that has crossed by permeation of the water chamber -1B-through a pipe -12-, and also recovering condensed water from the raw water chamber -1A-through the middle of a pipe -13-. To the pipe -13-, by means of which the condensed water is recovered, a pressure gauge -6- and an opening valve -closure -7- have been installed.
[Examples and Comparative Examples Using Modified Polyvinyl Alcohol as a Second Component for Improving the Rejection Rate]
[Example I-1]
After degrading with chlorine an "ES20" ultra-low pressure RO membrane based on aromatic polyamide, manufactured by Nitto Denko Corporation under the following degradation conditions, a treatment for improving the rejection rate was carried out under the following conditions by using arginine (manufactured by Ajinomoto Co., Inc., molecular weight: 174) and aspartame (manufactured by Ajinomoto Co., Inc., molecular weight: 294) as a low molecular weight amino compound; AL tannic acid (manufactured by Fuji Chemical Industry Co., Ltd., molecular weight: 500 or more) as polyphenol; and modified cationic polyvinyl alcohol "GOHSEFIMER K-210" (manufactured by The Nippon Synthetic Chemical Industry Co., Ltd.) as modified polyvinyl alcohol. Regarding the order of addition of the components of improvement of the rejection rate and the water supply time, after mixing an aqueous solution with arginine, aspartame, and tannic acid AL was supplied for 3 hours, adding GOHSEFIMER K-210 to the aqueous solution before

mentioned, and the treatment was carried out for 1 hour.
Before and after this rejection rate improvement treatment, the following performance evaluations were carried out using an aqueous NaCl solution. In addition, after having carried out the treatment of improvement of the rejection rate and the evaluation of the yield using an aqueous solution of NaCl, a liquid prepared as raw water by adding 30 ppm of "IK-110" manufactured by Kurita Water Industries Ltd. as a biologically treated sludge control agent from a Kurita Development Center waste water recovery apparatus was supplied under the conditions indicated below, and the rejection rate and the permeation flow stability were observed. after a water supply carried out for a predetermined period of time.
<Degradation Conditions>
An aqueous solution of sodium hypochlorite with a concentration of 100 ppm (ph: 7.0) was supplied at an inlet pressure of 0.75 MPa and a water temperature of 25 ° C for 24 hours.
<Treatment Conditions for the Improvement of the Rejection Rate>
Concentration of each component to improve the rejection rate: 100 mg / L
Inlet pressure: 0.2 MPa Permeation flow: 0.3 m3 / (m2 · day) Water temperature: 25ºC
<Performance Evaluation Conditions>
NaCl concentration: 500 mg / L Inlet pressure: 0.75 MPa Water temperature: 25ºC pH: 6.5 to 7.0

<Biologically Treated Water Supply Conditions>
Water temperature: 25ºCpH: 6.5 to 7.05 Recovery rate: 80%Water supply time: 200 hours
[Example I-2]
10 Except that the modified polyvinyl alcohol was changed to "ECOMATI WO-320N" (a modified polyvinyl alcohol having a poly (alkylene oxide) chain), the treatment for improving the rejection rate was carried out. in a manner similar to that of Example I-1, and performance and stability were evaluated.
15 [Example I-3]
Except that the modified polyvinyl alcohol was changed to "GOHSENAL T-330H" (a modified polyvinyl alcohol in a carboxyl group), the treatment for the improvement of the rejection rate was carried out in a manner similar to that of Example I -1, and were evaluated
20 performance and stability.
[Example I-4]
Except that the modified polyvinyl alcohol was changed to “GOHSERAN L-3266”
25 (a modified polyvinyl alcohol in a sulfonic acid group)), the treatment for the improvement of the rejection rate was carried out in a manner similar to that of Example I-1, and the yield and stability were evaluated.
[Examples I-5 to 8]
Except that the low molecular weight amino compounds were changed to arginine only, the rejection rate improvement treatments were carried out in a manner similar to the respective treatments of Examples I-1 to 4, and were They evaluated performance and stability.

[Example I-9]
Except that the low molecular weight amino compounds were not used, the treatment for the improvement of the rejection rate was carried out in a manner similar to that of Example I-1, and the yield and stability were evaluated.
[Example I-10]
Except that the modified polyvinyl alcohol was changed to “ECOMATI WO-320N”, the
The treatment for the improvement of the rejection rate was carried out in a manner similar to that of Example I-9, and the performance and stability were evaluated.
[Example I-11]
Except that the modified polyvinyl alcohol was changed to "ECOMATI WO-320N" and "GOHSEFIMER K-210" used together, the treatment for the improvement of the rejection rate was carried out in a manner similar to that of Example I -9, and performance and stability were evaluated.
20 [Example I-12 to 15]
Except that the aqueous solution in which the low molecular weight amino compounds, polyphenol, and modified polyvinyl alcohol were mixed together were supplied for 4 hours, the treatment for improving the rejection rate was
25 carried out in a manner similar to that of the respective treatments of Examples I-1 to 4, and the performance and stability were evaluated.
[Comparative Example I-1]
30 Except that the treatment for the improvement of the rejection rate was carried out only using polyphenol, and that the low molecular weight amino compounds and the modified polyvinyl alcohol were not used, the treatment for the improvement of the Rejection rate was carried out in a manner similar to that of Example I-1, and performance and stability were evaluated.

[Comparative Example I-2]
Except that the modified polyvinyl alcohol was not used, the treatment for the improvement of the rejection rate was carried out in a manner similar to that of Example I-1, and the performance and stability were evaluated.
[Comparative Example I-3]
Except that the low molecular weight amino compounds were not used, and
10 that a polyvinyl alcohol was used (average degree of polymerization: 2,000, degree of saponification: 99%, manufactured by Kishida Chemical Co., Ltd.) instead of using modified polyvinyl alcohol, the treatment for improving the rate of rejection was carried out in a manner similar to that of Example I-1, and performance and stability were evaluated.
The results of the previous Examples I-1 to 15 and Comparative Examples I-1 to 4 are shown collectively in Tables 1 and 2.
In addition, the permeation flow, salt rejection rate, and elimination rate were calculated from the following equations:
20 Permeation flow [m3 / (m2 · day)] = amount of permeation water [m3 / day] / membrane area [m2] x temperature conversion factor [-] Salt rejection rate [%] = ( 1 - electrical conductivity [mS / m] of permeated liquid / electrical conductivity [mS / m] of condensed liquid) x 100
25 Elimination rate [%] = (1-TOC [mg / L] of permeate liquid / TOC [mg / L] of condensed liquid) x 100

[Examples and Comparative Example Using High Molecular Weight Polysaccharide or Poly (Amino Acid) as Second Component for Improving the Rejection Rate]
In the following examples and comparative examples, the following membrane was used as a degraded membrane subjected to the treatment for the improvement of the rejection rate.
Degraded membrane: a membrane prepared by accelerated degradation in which an ultra-low pressure “ES20” RO membrane based on aromatic polyamide (original membrane) manufactured by Nitto Denko Corporation was immersed in an aqueous solution containing sodium hypochlorite (free chlorine: 100 mg / L) for 24 hours.
For membrane evaluation after the treatment of improvement of the rejection rate, an aqueous solution of NaCl (pH: 6.5) with a concentration of 1,000 mg / L was used as an aqueous solution for performance evaluation, this solution being supplied aqueous NaCl at an operating pressure of 0.75 MPa and a temperature of 24 ° C ± 2 ° C, and the permeation flow and salt rejection rate after 2 hours and after 200 hours from the start of the water supply were obtained . In addition, the procedures for calculating the permeation flow and salt rejection rate were similar to those described in Example I-1.
As water for the treatment of improvement of the rejection rate, the following aqueous solutions A to L prepared using arginine (manufactured by Ajinomoto Co., Inc.), aspartame (manufactured by Ajinomoto Co., Inc.), tannic acid, were used (manufactured by Fuji Chemical Industry Co., Ltd., tannic acid AL food additive, molecular weight: 500 or more), xanthan gum (manufactured by San-Ei Yakuhin Boeki Co., Ltd., "Bisfect XA", weight molecular:
1,000,000 or more (per LC-OCD, based on dextran using HW65s)), an agar rubber (manufactured by San-Ei Yakuhin Boeki Co., Ltd., “Guarcol F50”, molecular weight: 1,000,000 or more ( by LC-OCD, based on dextran using HW65s)), sodium alginate (manufactured by Kimica Corp., “Kimica Algin I-3”, molecular weight: 1,000,000 or more (by LC-OCD, based on dextran using HW65s) ), a carboxymethyl cellulose (manufactured by Daicel Fine Chem Ltd., "CMC 1240", molecular weight: approximately 380,000 (submitted by the manufacturer)), and a polylysine (manufactured by JNC, molecular weight: approximately 4,500 to 5,000 (presented by the manufacturer)). The water supply pressure of the rejection treatment improvement water to an RO membrane during the rejection rate improvement treatment was adjusted to 0.2 MPa, and the water temperature was adjusted

during the water supply at 24ºC ± 2ºC.Aqueous solution A: aqueous solution containing 50 mg / L arginine
5 Aqueous solution B: aqueous solution containing 50 mg / L aspartame Aqueous solution C: aqueous solution containing 50 mg / L tannic acid Aqueous solution D: aqueous solution containing 50 mg / L arginine, 50 mg / L
10 aspartame, and 50 mg / L tannic acid Aqueous solution E: aqueous solution containing 50 mg / L xanthan gum Aqueous solution F: aqueous solution containing 50 mg / L arginine, 50 mg / L
15 aspartame, and 50 mg / L of tannic acid, and 50 mg / L of xanthan gum Aqueous solution G: aqueous solution containing 50 mg / L gum agar Aqueous solution H: aqueous solution containing 50 mg / L alginate sodium
20 Aqueous solution I: aqueous solution containing 50 mg / L carboxymethyl cellulose Aqueous solution J: aqueous solution containing 50 mg / L polylysine
25 Aqueous solution K: aqueous solution containing 50 mg / L of arginine, 50 mg / L of aspartame, and 50 mg / L of tannic acid, and 50 mg / L of polylysine (to avoid aggregation, the pH was adjusted to 3 , 5 with hydrochloric acid).
Aqueous solution L: aqueous solution containing 50 mg / L of tannic acid and 50 mg / L of 30 polylysine (to avoid aggregation, the pH was adjusted to 3.5 with hydrochloric acid). [Examples II-1 to 11, Comparative Examples II-1 to 7] In Examples II-1 to 3 and II-5 to 10 and in Comparative Examples II-6 and 7, after treatment water I was passed I of improvement of the rejection rate, shown in Table 3 through the degraded membrane during the time shown in Table 3., and water II of

treatment of improvement of the rejection rate shown in Table 3, was passed through the membrane during the time shown in Table 3, the performance evaluation was carried out.
5 In Examples II-4, II-11, and Comparative Examples II-2 to 5, after passing through the membrane it degrades during the time shown in Table 3 the water I for the treatment of improving the rate of rejection, the performance evaluation was carried out.
In Comparative Example II-1, the performance evaluation was carried out without performing the rejection rate improvement treatment.
The results are shown in Table 3.
The performance evaluation of the original non-degraded membrane was also carried out in a manner similar to that described above, and the results thereof are also shown in Table 3.

From the results that have been shown, it is observed that the RO membrane treated by the treatment of improvement of the rejection rate of the present invention is excellent in terms of stability of removal performance (rejection rate) and flow stability (sustainability). of resistance to contamination).
5 In Examples II-8 to II-11 in which polylysine was used, the stability of the salt rejection rate was especially excellent. The reason for this is believed to be the strong interaction with tannic acid.
10 While the present invention has been described in detail with reference to specific embodiments, it is apparent to those skilled in the art that different modifications and changes can be made without departing from the scope of the present invention.
This application claims the advantages of Japanese Patent Application No. 2012-287663, 15 filed on December 28, 2012, which is incorporated herein by reference in its entirety.
Reference Number List
20 1 container 1A raw water chamber 1B permeation water chamber 2 cell with flat membrane 3 agitator
25 21 RO membrane 22 polyphenol 23 second component to improve the rejection rate 24 low molecular weight amino compound

权利要求:
Claims (19)
[1]
one. A method for improving the rejection rate of a reverse osmosis membrane, the method comprising a step, in which an aqueous solution containing a polyphenol is allowed to pass through a reverse osmosis membrane, so that the The method further comprises a step to allow an aqueous solution containing at least one type selected from the group consisting of a modified polyvinyl alcohol, a high molecular weight polysaccharide, and a poly (amino acid) to pass through the membrane of reverse osmosis.
[2]
2. The method for improving the rejection rate of a reverse osmosis membrane, according to claim 1, wherein an aqueous solution, containing a polyphenol and, at least, a type selected from the group consisting of a Modified polyvinyl alcohol, a high molecular weight polysaccharide, and a poly (amino acid) is passed through the reverse osmosis membrane.
[3]
3. The process for improving the rejection rate of a reverse osmosis membrane, according to claim 1, wherein after passing the aqueous solution containing a polyphenol through the reverse osmosis membrane, the aqueous solution containing at least one type selected from the group consisting of a modified polyvinyl alcohol, a high molecular weight polysaccharide, and a poly (amino acid) is passed through the reverse osmosis membrane.
[4]
Four. The method for improving the rejection rate of a reverse osmosis membrane, according to claim 3, wherein the aqueous solution containing at least one type selected from the group consisting of a modified polyvinyl alcohol, a High molecular weight polysaccharide, and a poly (amino acid) contains a polyphenol.
[5]
5. The process for improving the rejection rate of a reverse osmosis membrane, according to any one of claims 1 to 4, further comprising a step of passing an aqueous solution containing an organic compound having an amino group with a molecular weight of 1,000 or less across the reverse osmosis membrane.
[6]
6. The process for improving the rejection rate of a reverse osmosis membrane, according to claim 5, wherein an aqueous solution containing a

at least one type selected from the group consisting of a modified polyvinyl alcohol, a high molecular weight polysaccharide, and a poly (amino acid) and an organic compound having an amino group and having a molecular weight of 1,000 or less It is passed through the reverse osmosis membrane.
[7]
7. The process for improving the rejection rate of a reverse osmosis membrane, according to claim 5, wherein after passing an aqueous solution containing a polyphenol and an organic compound with an amino group and having a molecular weight of 1,000 or less through the reverse osmosis membrane, an aqueous solution containing at least one type selected from the group consisting of a modified polyvinyl alcohol, a polysaccharide is passed through said reverse osmosis membrane of high molecular weight and a poly (amino acid).
[8]
8. The process for improving the rejection rate of a reverse osmosis membrane according to claim 7, wherein the aqueous solution containing at least one type selected from the group consisting of a modified polyvinyl alcohol, a polysaccharide of High molecular weight and a poly (amino acid), contains a polyphenol and an organic compound that has an amino group and has a molecular weight of 1,000 or less.
[9]
9. The method for improving the rejection rate of a reverse osmosis membrane, according to claim 1, the polyphenol includes a tannic acid.
[10]
10. The method for improving the rejection rate of a reverse osmosis membrane according to claim 1, wherein the poly (amino acid) comprises a polylysine.
[11]
eleven. The method for improving the rejection rate of a reverse osmosis membrane according to claim 1, wherein the modified polyvinyl alcohol includes at least one type selected from the group consisting of cationic modified polyvinyl alcohol having a cationic group as a modifying group, an anionic modified polyvinyl alcohol having an anionic group as a modifying group, and a modified polyvinyl alcohol having a poly (alkylene oxide) chain.
[12]
12. The method for improving the rejection rate of a reverse osmosis membrane according to claim 1, wherein the high molecular weight polysaccharide comprises at least one type selected from the group consisting of rubber

Xanthan, agar gum, carboxymethyl cellulose and its salts, an alginic acid and its salts, and a chitosan.
[13]
13. The method for improving the rejection rate of a reverse osmosis membrane, according to claim 1, wherein the total amount of the polyphenol and, at least, a type selected from the group consisting of modified polyvinyl alcohol, the high molecular weight polysaccharide, and the poly (amino acid) that is supplied to the reverse osmosis membrane and that is calculated from the concentrations of the aqueous solutions and the amounts thereof that are passed through the membrane of reverse osmosis, it is adjusted so that the weight ratio of polyphenol to at least one type selected from the group consisting of modified polyvinyl alcohol, high molecular weight polysaccharide, and poly (amino acid) is in a range of 1: 0.1 to 5.
[14]
14. The process for improving the rejection rate of a reverse osmosis membrane, according to claim 5, wherein the organic compound having an amino group and having a molecular weight of 1,000 or less, comprises arginine and / or aspartame
[15]
fifteen. The process for improving the rejection rate of a reverse osmosis membrane, according to claim 5, wherein the total amount of the polyphenol and the organic compound having an amino group and having a molecular weight of 1,000 or less supplied to the reverse osmosis membrane and which is calculated from the concentrations in the aqueous solutions and the amounts thereof that are passed through the reverse osmosis membrane, is adjusted so that the weight ratio from the polyphenol to the organic compound that has an amino group and that has a molecular weight of 1,000 or less is in a range of 1: 0 to 2.
[16]
16. The process for improving the rejection rate of a reverse osmosis membrane, according to claim 1, wherein the pressure during the water supply is 0.1 to 0.5 MPa, and the permeation flow It is 0.1 to 1.0 m3 / (m2 · day).
[17]
17. Reverse osmosis membrane treated by the process for improving the rejection rate, according to any of claims 1 to 16.
[18]
18. Agent for improving the rejection rate for a reverse osmosis membrane,

whose agent comprises a polyphenol and at least one type selected from the group consisting of a modified polyvinyl alcohol, a high molecular weight polysaccharide, and a poly (amino acid).
[19]
19. The agent for improving the rejection rate for a reverse osmosis membrane, according to claim 18, further comprising an organic compound having an amino group and having a molecular weight of 1,000 or less.

类似技术:

公开号 | 公开日 | 专利标题

ES2546703B2|2016-10-07|PROCEDURE FOR THE IMPROVEMENT OF THE REVERSE RATE OF MEMBRANES OF REVERSE OSMOSIS, AGENT FOR THE IMPROVEMENT OF THE REJECTION AND MEMBRANE RATE OF REVERSE OSMOSIS

TWI478763B|2015-04-01|Through the membrane to prevent the rate of lifting methods and through the membrane

US10315169B2|2019-06-11|Universal scalable and cost-effective surface modifications

ES2734078T3|2019-12-04|Method to improve the blocking rate of a reverse osmosis membrane, and use of a treatment agent to improve the blocking rate of a reverse osmosis membrane

CN102921315B|2014-12-10|Anti-pollution reverse osmosis membrane and preparation method thereof

Maryam et al.2020|A study on behavior, interaction and rejection of Paracetamol, Diclofenac and Ibuprofen | from wastewater by nanofiltration membranes

JP2009165949A|2009-07-30|Antibacterial separative membrane, its manufacturing method, and manufacturing apparatus of antibacterial separative membrane

WO2012121209A1|2012-09-13|Method for improving blocking rate of permeable membrane, treatment agent for improving blocking rate, and permeable membrane

He et al.2019|Non-organic solvent prepared nanofiltration composite membrane from natural product tannic acid | and cyclohexane-1, 4-diamine |

US10532328B2|2020-01-14|Polyaniline-based chlorine resistant hydrophilic filtration membranes

WO2014098059A1|2014-06-26|Method for hydrophilizing reverse osmosis membrane

US20210339205A1|2021-11-04|Water treatment chemical for membranes and membrane treatment method

WO2017122207A1|2017-07-20|Modified polyamide membranes

AU2013247863B2|2017-08-17|Agent and method for improving blocking rate of reverse osmosis membrane, and reverse osmosis membrane

An et al.2011|Study on removal of organic matters in water by PVA modified PA-TFC nanofiltration membrane

JP2014050783A|2014-03-20|Check ratio improvement method of reverse osmotic membrane

JP5929296B2|2016-06-01|Reverse osmosis membrane rejection improvement method

JP2020069469A|2020-05-07|Composite semipermeable membrane

同族专利:

公开号 | 公开日

SA515360694B1|2018-05-24|

TW201440880A|2014-11-01|

ES2546703B2|2016-10-07|

US10046280B2|2018-08-14|

ES2546703R1|2016-01-11|

JP6251953B2|2017-12-27|

CN104884152B|2017-10-13|

CN104884152A|2015-09-02|

US20150306545A1|2015-10-29|

TWI607797B|2017-12-11|

WO2014103822A1|2014-07-03|

JP2014128760A|2014-07-10|

引用文献:

公开号 | 申请日 | 公开日 | 申请人 | 专利标题

JPS6111643B2|1978-06-26|1986-04-04|Toyo Boseki|

US4765897A|1986-04-28|1988-08-23|The Dow Chemical Company|Polyamide membranes useful for water softening|

JP3212129B2|1992-03-11|2001-09-25|ダイセル化学工業株式会社|New composite separation membrane and wastewater treatment method using the same|

JP3399636B2|1994-05-16|2003-04-21|日東電工株式会社|Seawater pretreatment method for seawater desalination using reverse osmosis membrane module|

JP2001149759A|1999-11-30|2001-06-05|Toray Ind Inc|Reverse osmosis separator and water producing method using the same|

SG181175A1|2003-02-25|2012-06-28|Kurita Water Ind Ltd|Detergent for washing selectively permeable membrane and method for washing|

JP2005329334A|2004-05-20|2005-12-02|Kurita Water Ind Ltd|Water treatment method and water treatment apparatus|

JP2006102624A|2004-10-05|2006-04-20|Nitto Denko Corp|Reverse osmosis membrane and its manufacturing method|

JP4868108B2|2004-10-18|2012-02-01|栗田工業株式会社|Permeation membrane blocking rate improver, rejection rate improving method, permeable membrane and water treatment method|

JP5151152B2|2006-03-29|2013-02-27|栗田工業株式会社|Nanofiltration membrane or reverse osmosis membrane rejection rate improver, rejection rate improvement method, nanofiltration membrane or reverse osmosis membrane, water treatment method, and water treatment apparatus|

JP2009022886A|2007-07-19|2009-02-05|Kurita Water Ind Ltd|Method for improving blocking rate of permeable membrane, blocking rate improved permeable membrane, and permeable membrane treatment method and apparatus|

JP2009056406A|2007-08-31|2009-03-19|Kurita Water Ind Ltd|Method of improving rejection rate of permeable membrane, permeable membrane having improved rejection rate, and permeable membrane apparatus|

US20100133172A1|2008-12-01|2010-06-03|Qun Song|Fouling resistant coating for membrane surfaces|

CN102695555B|2009-09-29|2015-11-25|栗田工业株式会社|Improve through the method for film prevention rate and through film|

US9216385B2|2010-10-04|2015-12-22|Saudi Arabian Oil Company|Application of rejection enhancing agents that do not have cloud point limitations on desalination membranes|

JP5914973B2|2011-03-09|2016-05-11|栗田工業株式会社|Method for improving rejection rate of permeable membrane and treatment agent for improving rejection rate|

JP5772083B2|2011-03-09|2015-09-02|栗田工業株式会社|Reverse osmosis membrane rejection rate improving method, rejection rate improving treatment agent, and reverse osmosis membrane|

JP2012250192A|2011-06-03|2012-12-20|Nitto Denko Corp|Composite semipermeable membrane and manufacturing method thereof|WO2016111371A1|2015-01-09|2016-07-14|東レ株式会社|Method for improving inhibition performance of semipermeable membrane, semipermeable membrane, and semipermeable membrane water production device|

JP6090362B2|2015-05-20|2017-03-08|栗田工業株式会社|Washing liquid and washing method for polyamide-based reverse osmosis membrane|

WO2017015291A1|2015-07-20|2017-01-26|Ecolab Usa Inc.|Methods of conditioning membranes|

JP6747926B2|2015-09-30|2020-08-26|日東電工株式会社|Method for manufacturing spiral type separation membrane element|

WO2018042060A1|2016-09-05|2018-03-08|Drei Lilien Pvg Gmbh & Co. Kg|Open-pore membrane having an inner space-spanning polymeric structural network for electrophoretic material-selective separation and methods for producing and using same|

JP6780427B2|2016-10-06|2020-11-04|東洋紡株式会社|How to regenerate the separation membrane module|

CN109289551B|2017-07-25|2021-12-21|中国石油化工股份有限公司|Reverse osmosis membrane and preparation method and application thereof|

CN109499383A|2018-11-22|2019-03-22|唐山钢铁集团有限责任公司|A kind of RO film healant and method for repairing and mending|

WO2021079867A1|2019-10-24|2021-04-29|三菱パワー株式会社|Desalination performance restoring agent for cellulose acetate membrane and method for restoring desalination performance of cellulose acetate membrane|

CN113559720A|2021-07-12|2021-10-29|武汉理工大学|Polyether sulfone hemodialysis membrane with heparin-like modified coating and preparation method and application thereof|

法律状态:
2016-10-07| FG2A| Definitive protection|Ref document number: 2546703 Country of ref document: ES Kind code of ref document: B2 Effective date: 20161007 |

优先权:

申请号 | 申请日 | 专利标题

JP2012287663A|JP6251953B2|2012-12-28|2012-12-28|Reverse osmosis membrane rejection improvement method|

PCT/JP2013/083850|WO2014103822A1|2012-12-28|2013-12-18|Method for improving rejection rate of reverse osmosis membrane, rejection rate improving agent, and reverse osmosis membrane|

[返回顶部]