JP2000288368A - Composite reverse osmosis membrane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make achievale a stable operation even under a high pressure above a specific numerical value, when a highly concentrated stock solution is treated, by forming a composite reverse osmosis membrane of a consolidated porous support and a film supported on the support. SOLUTION: The composite reverse osmosis membrane is formed of a consolidated porous support and a film supported on the porous support. The porous support is preferably treated by consolidation at 10 kgf/cm2 or more and is preferably thinner by 5 μm or more than before the consolidation treatment. In addition, the pure water permeation amount by the consolidated porous support is 1 m3/m2/day or more at 1 kgf/cm2 measured pressure and at 25 deg.C measured temperature and the structural part with a digital section of the porous support is preferably collapsed. Further, the active layer of the reverse osmosis membrane may be formed on the consolidated porous membrane. Thus it is possible to maintain the water permeation amount and the salt blocking performance at a high level without generating a consolidation phenomenon, when an operation is carried out under high pressure and consequently, stabilize the operation for a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite reverse osmosis membrane using a porous support membrane having a sufficient amount of permeated water even when compacted by use under high pressure. The composite reverse osmosis membrane of the present invention is suitable for treating a high concentration stock solution, and is excellent in high salt rejection, high water permeability and pressure resistance.

[0002]

2. Description of the Related Art At present, as a reverse osmosis membrane widely used industrially, there is an asymmetric membrane of cellulose acetate. For example, a lob type membrane described in US Pat. No. 3,133,132 or US Pat. No. 3,133,137 is known. ing. Further, as a reverse osmosis membrane having a different structure from the above, a composite reverse osmosis membrane in which an active thin film having substantially selective separation properties is formed on a microporous support membrane is also known.

[0003] As such a composite reverse osmosis membrane, specifically, a polyamide thin film obtained by interfacial polymerization of a polyfunctional aromatic amine and a polyfunctional aromatic acid halide formed on a support membrane (for example, JP-A-55-l47l06, JP-A-Showa
62-12l603, JP-A-63-2l8208, JP-A-2-l87l35, etc.) or a thin film made of polyamide obtained by interfacial polymerization of a polyfunctional aromatic amine and a polyfunctional alicyclic acid halide. What was formed on the film (for example,
No. l-42308) is known. Usually, these reverse osmosis membranes are formed into a spiral shape or the like and used for various purposes.

In order to perform separation using such a reverse osmosis membrane, it is necessary to apply a pressure higher than the osmotic pressure difference between the stock solution and the permeate to the stock solution. For example, the osmotic pressure of seawater having a concentration of 3.5% is about 25 kgf / cm ² at 25 ° C. In order to obtain fresh water by actually treating such seawater with a composite reverse osmosis membrane, usually, a spiral type element wound in a spiral shape, or an element obtained by connecting two to six of these in series is placed in a pressure vessel. After loading, the seawater is pressurized so that the recovery rate of each element is about 10%, and the processing is performed to improve the overall recovery rate.

[0005] For example, the overall recovery rate (freshwater production rate) is 40%.
When the treatment of seawater is performed so that the concentration of the concentrated seawater is about 6%, the osmotic pressure becomes about 45 kgf / cm ² . However, in practice, it is necessary to apply a pressure about 20 kgf / cm ² higher than the osmotic pressure to the undiluted seawater in order to obtain a sufficient amount of permeated water and water quality. Operation at about 65 kgf / cm ² is required. When a higher recovery rate is required, for example, when a seawater desalination operation is performed at a freshwater recovery rate of 60%, the obtained concentrated seawater has a concentration of about 9% and an osmotic pressure of about 70 kgf / cm ^2. , And it is necessary to operate at a pressure of about 90 kgf / cm ² .

Conventional composite reverse osmosis membranes are formed from a porous support membrane (for example, an ultrafiltration membrane made of polysulfone) and a synthetic polymer skin layer as described above. And the amount of permeated water decreases, and stable operation cannot be performed. In order to solve such a problem, the structure of the support is changed (Japanese Patent Laid-Open No. 8-168658 or the like) or the structure of the permeation channel material is changed (Japanese Patent Application Laid-Open No. 9-141060, Japanese Patent Application Laid-Open No. 9-14106).
No. 7, etc.) have also been proposed, but none of them have stable operation such as a change in initial performance according to the operation, and do not have sufficient pressure resistance.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art. In the treatment of a high-concentration stock solution, a high pressure, especially 70 kgf is used.
An object of the present invention is to provide a composite reverse osmosis membrane capable of stable operation even under a high pressure of / cm ² or more.

Generally, in a composite reverse osmosis membrane, in order to form a synthetic polymer skin layer on the surface stably and uniformly and to obtain high rejection performance, it is necessary to design the surface structure of the porous support membrane relatively densely. Usually, a wet method is used for producing a porous support membrane, and the pore size increases continuously from the membrane surface to the opposite surface. Therefore, when the surface structure of the membrane is relatively dense, that is, when the pore size of the surface layer is set small, the whole support membrane becomes dense and the amount of permeated water decreases. When such a support membrane is compacted, pores are likely to be clogged, and the amount of permeated water of the composite reverse osmosis membrane using this as a base material is significantly reduced.

On the other hand, when the pore size of the surface layer of the porous support membrane is set to be large, a sparse structure is exhibited over the entire support membrane, and pore blockage is suppressed and the decrease in the amount of permeated water is reduced, but the pore size of the surface layer is reduced. Is large, the synthetic polymer skin layer cannot be formed stably and uniformly, and as a result, the blocking performance of the composite reverse osmosis membrane is lowered.

The present invention provides a composite reverse osmosis membrane comprising a consolidated porous support and a thin film supported on the porous support. 10 kg compaction treatment for porous support
f / cm ² or more, and the thickness of the support is preferably at least 5 μm thinner than before the consolidation treatment. The amount of pure water permeated by the consolidated porous support was measured at a measurement pressure of 1 kgf / cm ² and a measurement temperature of 25 kg / cm ² .
It is preferably at least 1 m ³ / m ² / day at ° C., and it is preferable that the cross-sectional finger structure of the porous support is crushed. The present invention also provides a method for producing a composite reverse osmosis membrane, which comprises preparing a consolidated porous membrane and forming an active layer of the reverse osmosis membrane thereon.

The composite reverse osmosis membrane of the present invention has a high amount of permeated water and a high salt rejection performance even when operated under high pressure due to consolidation prior to use, and can be operated stably for a long time. .

[0012]

DETAILED DESCRIPTION OF THE INVENTION (Porous support) As the porous support used in the present invention, any of those conventionally used as a support for a composite reverse osmosis membrane may be used. Organic polymer, polyamide-based, polyimide-based, polysulfone-based, polyacrylonitrile-based, polyvinyl alcohol-based, ethylene-vinyl alcohol copolymer-based, and the like.Polysulfone, polyarylethersulfone such as polyethersulfone, polyimide, polyolefin Vinylidene chloride is preferred.

In particular, a porous support membrane made of polysulfone or polyarylethersulfone is preferably used because it is chemically, mechanically and thermally stable. Such a porous support membrane is usually 25 to 125 μm, preferably about 40 μm.
It has a thickness of 75 μm, but is not necessarily limited to these.

To prepare a film forming solution, a solvent capable of dissolving these film materials, for example, N-methyl-2
-Pyrrolidone, N, N-dimethylacetamide, N, N-
Nitrogen-containing compounds such as dimethylformamide, dimethylsulfoxide, and pyridine; polyhydric alcohols such as diethylene glycol, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol dibutyl ether and derivatives thereof; and ether acetals such as 1,4-dioxane, tetrahydrofuran, and ethyl-butyl ether Can be used. These solvents may be used alone or as a mixture of two or more. Further, water, which is a poor solvent, or alcohols such as methanol, ethanol and isopropanol may be added in a range not exceeding 10% by weight.

Using these solvents, a solution concentration of 5 to 20% by weight, preferably 10 to 18% by weight, more preferably 1 to 18% by weight.
A film forming solution of 0 to 16% by weight is prepared. If the solution concentration is lower than these ranges, the viscosity is low and a uniform film cannot be formed. On the other hand, if the concentration is higher than this range, it becomes difficult to form a film, and the film becomes dense, the desired film structure cannot be obtained, and the amount of permeated water decreases.

The film forming solution used in the present invention is -20 to 6
It is prepared in a temperature range of 0 ° C, preferably 0 to 40 ° C. A method for producing a porous support by a wet phase inversion film forming method using this solution will be described below.

The composite reverse osmosis membrane of the present invention has the following membrane shape.
The shape may be any of a flat membrane, a hollow fiber, and a tube, and is not particularly limited. In the case of a flat film, for example, the above solution is applied to a substrate such as a woven fabric or a nonwoven fabric by casting or dipping, and then immersed in a coagulation liquid. The coating thickness of the solution on the substrate is 25 to 400 μm, preferably 30
To 250 μm, more preferably 90 to 200 μm. If the coating thickness is smaller than the above range, defects occur in the porous support, while if too thick, the amount of permeated water decreases.

As the coagulating liquid, water, alcohols such as methanol, ethanol, isopropyl alcohol and the like and a mixed solution comprising at least two of these are used, but not limited thereto.

The temperature of the coagulating liquid is 0 to 80 ° C., preferably 5 to 80 ° C.
To 50 ° C, more preferably 10 to 30 ° C. If the temperature of the coagulating liquid exceeds 80 ° C., gelation occurs rapidly, and the resulting film has a sparse structure, and a sufficient PEG rejection cannot be obtained. No film. Further, if the solidification temperature is lower than the above range, the membrane becomes dense and the amount of permeated water decreases, while if it is higher than this, the membrane becomes too sparse to form a synthetic polymer skin layer having stable performance on the membrane surface. Can not.

The substrate coated with the film-forming solution needs to be supplied with a new coagulating liquid at all times during the coagulation process.
If the supply of the new coagulating liquid to the film surface is not sufficient, a solvent for dissolving the porous film is present in the coagulating liquid on the film surface, solidification is inhibited, and the film surface has a sparse structure. Such a method of constantly supplying a new coagulating liquid to the film surface in the solidification process is not particularly limited. For example, a method in which a substrate such as a woven fabric or a nonwoven fabric coated with a film forming solution is continuously moved in the coagulating solution. Alternatively, a method of circulating the coagulating liquid itself can be employed. When continuously moving a substrate such as a woven or non-woven fabric coated with a film forming solution,
Its speed is 3-100 m / min, preferably 5-50 m / min. Under these conditions, a new coagulating liquid is constantly supplied to the film surface, and the structure of the film surface can be made dense. If the film forming speed is lower than the above range, the film surface becomes sparse, and a desired dense film surface structure cannot be formed. Also, 1
If the speed is higher than 00 m / min, a non-uniform portion occurs on the film surface during film formation.

Further, in order to densify the surface of the porous support, the support may be dried at 30 to 200 ° C., preferably 50 to 150 ° C. In this case, when forming a reverse osmosis membrane, which will be described later, the support membrane is immersed in a mixed solvent (solution concentration: 5 to 70% by weight) of water and alcohol (eg, methanol, ethanol, isopropyl alcohol) for the purpose of moistening the support membrane. Again, a method of replacing with water is used.

In the present invention, a polyethylene glycol (PEG; average molecular weight: 20,000) solution was used as a method for evaluating the performance of the porous support membrane. The evaluation cell used was one capable of circulating the evaluation solution, PEG concentration: 0.5% by weight, evaluation pressure: 1 kgf / cm ² , temperature: 25 ° C., circulating flow rate: 1
It evaluated in L / min. The porous support of the present invention obtained under the above-mentioned film forming conditions has a PEG rejection under such conditions of 10 to 90%, preferably 10 to 50%. If the PEG rejection is lower than this range, the film surface is sparse and a synthetic polymer skin layer having high rejection cannot be formed. On the other hand, if the rejection is higher than the above range, the film surface becomes too dense, and when the consolidation occurs, the clogging of the surface holes is promoted.

The amount of permeated pure water of the porous support is 5 m ³ /
m ² / day or more (evaluation pressure; 1 kgf / cm ² , temperature: 2
5 ° C.), preferably 10 m ³ / m ² / day or more. If the amount of permeated water is lower than this, the surface pores are closed due to consolidation, and the amount of permeated water is significantly reduced.

It is preferable that the separation layer exhibiting the above-mentioned PEG rejection is located on the outermost layer, and the thickness of the layer is 20% of the thickness of the porous support (not including the base material such as a nonwoven fabric).
Or less, preferably 15% or less. If such a layer is thicker than this, the resistance is increased, a sufficient amount of permeated water cannot be secured, and the surface pores are likely to be clogged when compacted.

(Consolidation treatment) The porous support thus produced is subjected to a consolidation treatment. The method of compaction is not particularly limited as long as pressure is applied to the porous support. For example, a method of applying pressure to the porous support with a compression roll, a method of applying pressure using a liquid such as water as a medium, and the like can be used. Further, the treatment may be performed in a flat film form,
After elementalization into a spiral shape or the like, consolidation treatment may be performed. It is preferable to use a compression roll for the consolidation treatment with the flat membrane, and it is preferable to use a liquid such as water as a medium when performing the consolidation treatment after the element formation. It is preferable that the pressure of the consolidation treatment on the porous support is high. However, if the pressure is too high, the pores of the porous support are blocked, and the resistance of the permeated water is undesirably high. Consolidation processing in element state is 10k
gf / cm ² or more, usually 10 to 200 kgf / c
m ² , preferably 10 to 100 kgf / cm ² .
In addition, when performing a consolidation process by a compression press or the like using a flat membrane,
The press pressure is 2 kgf / cm ² or more and 150 kgf / c.
m ² or less. Press pressure is 2kgf /
If it is smaller than ² cm, a sufficient consolidation effect cannot be obtained.
If it exceeds kgf / cm ² , the reduction in the amount of permeated water becomes too large due to the compaction.

In the consolidation treatment, the porous support may be in a wet state containing a liquid such as water, or may be in a dried state after impregnating with a wetting agent such as glycerin. After placing a protective film, a separator, and the like on the porous support so that the surface of the porous support is not damaged by the consolidation, the consolidation may be performed.

The thickness of the porous support is preferably reduced by 5 μm or more, more preferably by 10 μm or more by a consolidation treatment. The consolidation has an upper limit of 80% of the thickness of the support after the treatment. When the obtained porous support is observed with an electron microscope, the cross-sectional finger-like structure is crushed, and the diameter in the film thickness direction is 1 μm or less.

The porous support membrane thus compacted needs to have a suitable pressure resistance, that is, a sufficient amount of pure water permeated during the compaction. For example, when an impervious film is placed on the surface of the porous support membrane and a water pressure of 120 kgf / cm ² is applied for 1 hour, the amount of permeated water is 1.0 m ³ / m ² /
It is preferably at least one day (evaluation pressure; 1 kgf / cm ² , temperature: 25 ° C.). The amount of permeated water during compaction is 1.0m
^When it is less than ³ / m ² / day, when a composite reverse osmosis membrane is formed using the porous support membrane, the amount of permeated water is greatly reduced during high-pressure operation.

(Formation of a thin film) Next, a thin film is formed on the porous support which has been subjected to the consolidation treatment. Conventionally, any method for forming a composite reverse osmosis membrane may be employed.

A film (skin layer) formed on a porous support
Can be formed by a polyamide-based or polyurea-based interfacial polymerization method, and can be easily produced by a conventionally known method. For example, using a porous support such as a porous polysulfone support membrane as a support membrane, at least one surface of which is metaphenylenediamine, piperazine,
An aqueous solution of a monomer and / or polymer having a reactive amino group such as polyethyleneimine is applied. Then, a solvent such as a polyfunctional acid chloride such as trimesic acid chloride or isophthalic acid chloride or a polyfunctional isocyanate such as tolylene diisocyanate, or a mixture thereof such as hexane is contacted, and interfacial polymerization is performed on the porous support to remove the polymer. A composite reverse osmosis membrane is obtained by forming a film having salt performance.

On such a composite reverse osmosis membrane surface, an organic substance,
And / or an organic polymer, preferably an organic material having a nonionic hydrophilic group, and / or a solution of the organic polymer is applied and then dried to obtain a composite reverse osmosis membrane. It is effective in improving the properties.

Examples of such organic substances and / or organic polymers include fluorine-containing polymers such as silicone rubber and polyethylene terephthalate, sulfonic acid group-containing organic polymers such as sulfonated polysulfone and sulfonated polyether sulfone, and polyethyleneimine. Such as amino group-containing organic polymers, polyimides, etc., for the purpose of maintaining high water permeability after coating and suppressing organic substances having hydrophilic groups, and / or organic polymers, particularly, charged adsorption. An organic material having a nonionic hydrophilic group and / or an organic polymer are preferred.

Examples of the organic substance and / or organic polymer having a nonionic hydrophilic group include nonionic hydrophilic substances such as polyvinyl alcohol, saponified polyethylene-vinyl acetate copolymer, polyvinylpyrrolidone, hydroxypropylcellulose and polyethylene glycol. Vinyl polymers having a hydrophilic group, condensation polymers, addition polymers, etc. are used.

As the solvent for the organic substance and / or the organic polymer, a solvent which does not damage the active film layer, for example, water, lower alcohol, halogenated hydrocarbon,
Examples thereof include aliphatic hydrocarbon, acetone, acetonitrile, and a mixed solvent thereof. Among them, in particular, aliphatic alcohols such as methanol, ethanol, propanol and butanol, halogenated aliphatic alcohols such as ethylene chlorohydrin, methoxymethanol, methoxyethanol and a mixed solvent of at least one of these lower alcohols with water, etc. May be used. In the case of a mixed solvent, the ratio of the lower alcohol to water is not particularly limited, but the ratio of water is preferably 0 to 90%. When water is used as the solvent, a surfactant may be added for the purpose of improving the wettability with the film.

[0035]

EXAMPLES Next, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. Example 1 A polysulfone ultrafiltration membrane (polysulfone layer, film thickness 50 μm) was used as a porous support, and pressed with a compression roll (pressure 20 kgf / cm ² ). When the thickness of the polysulfone layer of the polysulfone ultrafiltration membrane after pressing was measured, it was 40 μm, and it was confirmed that the polysulfone was compressed by 10 μm. A composite reverse osmosis membrane comprising a crosslinked wholly aromatic polyamide skin layer comprising metaphenylenediamine as an amine component and trimesic acid chloride and isophthalic acid chloride as acid chloride components was prepared on the polysulfone ultrafiltration membrane.

Using this reverse osmosis membrane, a saline solution (5.8%)
Was subjected to a reverse osmosis membrane permeation test (pressure 90 kgf / cm ² , outlet flow rate 5 L / min, 25 ° C., pH 7). The reverse osmosis membrane performance 60 minutes after the start of operation was 99.7% rejection, and the amount of permeated water was 0. It was .90 m ³ / m ² / day. When the performance was measured after further operating under the same conditions for 100 hours, no significant change was observed in the performance at a rejection rate of 99.7% and a permeated water amount of 0.86 m ³ / m ² / day.

Comparative Example 1 Example 1 was repeated except that a polysulfone ultrafiltration membrane not treated with a compression roll was used as a support.
A composite reverse osmosis membrane was produced in the same manner as described above. When the performance of the reverse osmosis membrane was measured, the performance of the reverse osmosis membrane 60 minutes after the start of the operation was 0.30% for salt permeability and 1.00 m ³ / m ^{2 for} permeated water.
/ Day. After operating under the same conditions for an additional 100 hours, the performance was measured.
%, And the permeated water amount was 0.78 m ³ / m ² / day, both the salt rejection and the permeated water amount were reduced, and stable operation was difficult.

Example 2 Polysulfone was dissolved in dimethylformamide (DMF) to prepare a 15% by weight solution.
(Solution temperature: 25 ° C). The obtained solution was continuously applied on a roll-shaped nonwoven fabric at a thickness of 130 μm, continuously immersed in water at 20 ° C., solidified and continuously wound to prepare a polysulfone porous support membrane. The speed (surface speed) at this time was 8 / min.

The obtained porous support membrane was set in a cell capable of circulating the supply liquid, and polyethylene glycol (PEG) was used.
(Molecular weight: 20,000) was evaluated using a solution. At this time, PEG
The concentration was 0.5% by weight, the evaluation pressure was 1 kgf / cm ² , the temperature was 25 ° C., and the circulation flow rate was 1 L / min. At this time, the rejection of PEG was 23%. The pure water permeated water amount of the membrane was 15 m ³ / m ² / day (evaluation pressure: 1 k
gf / cm ² , temperature: 25 ° C.). The obtained membrane was passed between two rolls at a pressure of 6 kgf / cm ² to perform a thickening treatment of the porous support membrane. The amount of pure water permeated through the obtained porous support membrane was 10 m ³ / m ² / day (evaluation pressure:
1 kgf / cm ² , temperature: 25 ° C.).

An aqueous solution containing 3.0% by weight of m-phenylenediamine, 0.15% by weight of sodium lauryl sulfate and 2.0% by weight of triethylamine and 4.0% by weight of camphorsulfonic acid was placed on the membrane. After contacting the porous polysulfone support membrane for a few seconds, excess aqueous solution was removed to form a layer of the aqueous solution on the support membrane.

Next, IP1016 containing 0.25% by weight of trimesic acid chloride was applied to the surface of the obtained film (Idemitsu Chemical Co., Ltd.).
(Isoparaffin-based hydrocarbon oil). Then, it was kept in a hot air dryer at 120 ° C. for 5 minutes to form a skin layer on the support to obtain a composite reverse osmosis membrane.

The obtained membrane was evaluated using a 3.5% by weight aqueous solution of sodium chloride under a pressure of 56 kgf / cm ^2. As a result, the blocking performance was 99.8%, and the permeated water amount was 0.80 (m ³ / m ³ ).
m ² / day). The obtained membrane is treated with the same aqueous solution for 120 k.
After pressurizing for 1 hour at gf / cm ² ,
As a result of evaluation in gf / cm ² , the blocking performance was 99.8%,
The amount of permeated water was 0.77 (m ³ / m ² / day), and no change in performance was observed.

Example 3 A reverse osmosis membrane was formed in the same manner as in Example 2, except that the porous support membrane was not compacted. The membrane performance was evaluated using a 3.5% by weight aqueous sodium chloride solution at a pressure of 56 kgf / cm ^2. As a result, the inhibition performance was 99.8% and the permeated water amount was 0.78 (m ³ / m ² /
Day).

The obtained membrane was made into an element, and the water pressure was 100
After pressurizing 0.5 hours kgf / cm ^2, again, as a result of evaluating a pressure 56kgf / cm ^2, rejection 99.
8%, and the amount of permeated water was 0.77 (m ³ / m ² / day).
The cross-section was observed with an electron microscope, and the diameter of the finger-like structure in the film thickness direction was measured to be 0.7 μm. Using this element, pressure of 90kgf for desalination of seawater
After operating for one month at / cm ² , the element is disassembled,
As a result of evaluation at a pressure of 56 kgf / cm ² again, the blocking performance was 99.8%, and the amount of permeated water was 0.75 (m ³ / m ² / day).

Further, the skin layer portion of the reverse osmosis membrane was removed using an aqueous solution of sodium hypochlorite (1%), and the amount of pure water permeated through the porous support membrane was 1.0 kgf / cm ² and the temperature was 2
The evaluation at 5 ° C. was 5 (m ³ / m ² / day), and it was confirmed that the decrease in the amount of permeated water due to the compaction of the support membrane was suppressed.

[0046]

The composite reverse osmosis membrane of the present invention has a high pressure (for example, 7
(0 kgf / cm ² or more), it has pressure resistance (suppression of a decrease in the amount of permeated water of the composite reverse osmosis membrane), and a stable amount of permeated water can be obtained. Such a composite reverse osmosis membrane is suitable for treating a high-concentration stock solution, for example, brackish water, seawater, or concentrated seawater, and can be operated stably.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hisao Hachisuka 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation F-term (reference) 4D006 GA03 HA41 KE03R KE06R KE30R MA07 MA09 MA10 MA22 MA31 MB06 MB18 MC54X MC62 MC63 NA46 NA49 NA54 NA65 PB03

Claims (7)

[Claims] 1. A composite reverse osmosis membrane comprising a consolidated porous support and a thin film supported thereon. 2. The composite reverse osmosis membrane according to claim 1, wherein the consolidation is performed at a pressure of ² kgf / cm ² or more. 3. The composite reverse osmosis membrane according to claim 1, wherein the reduction in thickness of the porous support due to the consolidation is 5 μm or more. 4. The consolidated porous support having a pure water permeated water amount of 1 kgf / cm ^{2 at} a measurement pressure of 1 ° C. at a measurement temperature of 25 ° C.
The composite reverse osmosis membrane according to claim 1, which is at least m ³ / m ² / day. 5. The composite reverse osmosis membrane according to claim 1, wherein the diameter in the thickness direction of the finger-shaped cross section of the consolidated porous support is 1 μm or less. 6. A method for producing a composite reverse osmosis membrane, comprising preparing a compacted porous support, and forming an active thin film of a reverse osmosis membrane thereon. 7. A method for treating a composite reverse osmosis membrane, comprising forming the composite reverse osmosis membrane into a spiral element and performing a compaction treatment using a liquid as a medium.