Toray Industries, Inc.

Katsufumi Oto

Kazuya Sugita

Masahiro Kimura

Yukio Nakagawa

Masaru Kurihara

Takao Sasaki

Hiroho Hirozawa

Masakazu Koiwa

Kentaro Takagi

Hiroki Tomioka

Yoshiki Okamoto

Hiroyuki Yamada

Tsuyoshi Hamada

Yutaro Suzuki

Akihiko Ito

Yoshinari Fusaoka

Kentarou Takagi

Tomoko Mitsuhata

To provide a separation membrane element that is able to increase the amount of permeate fluid per unit time and also able to improve stability performance, provided is a separation membrane element, comprising a separation membrane and a permeate spacer, wherein a separation functional layer is arranged on the surface of said separation membrane and a nonwoven fabric served as a substrate is arranged on the back surface of said separation membrane, wherein said permeate spacer is arranged on the back surface side of said substrate, wherein said permeate spacer is made of a different material from said separation membrane, and a projection area ratio of said permeate spacer to said separation membrane is 0.03 to 0.80.

Separation membrane element

A composite semipermeable membrane comprising a porous support membrane on which a separating functional polyamide layer resulting from the polycondensation reaction of polyfunctional aromatic amines with polyfunctional acid halides is formed, wherein the separating functional polyamide layer has carboxy groups, amino groups, phenolic hydroxyl groups, and azo groups, wherein X, the ratio of the amino groups (molar equivalent of the amino groups/(molar equivalent of the azo groups+molar equivalent of the phenolic hydroxyl groups+molar equivalent of the amino groups)) on a feed water contact surface of the separating functional polyamide layer (an A surface), is in the range 0.5 or less, and X, the ratio of the amino groups (molar equivalent of the amino groups/(molar equivalent of the azo groups+molar equivalent of the phenolic hydroxyl groups+molar equivalent of the amino groups)) on a permeate-side surface of the separating functional polyamide layer (a B surface), i.e., the opposite side to the A surface, is in the range of 0.5 to 1. The present invention provides a composite semipermeable membrane that achieves a balance between high solute removal properties and a high permeate flow rate and has high organic-solvent resistance, and a method for producing same.

Composite semipermeable membrane and method for producing same

A composite semipermeable membrane which satisfies the following relationship when seawater at 25&#xb0; C. having a pH of 6.5, a boron concentration of 5 ppm and a TDS concentration of 3.5% by weight is permeated under an operation pressure of 5.5 MPa: Boron removal ratio (%)&#x2267;95&#x2212;4&#xd7;membrane permeation flow rate (m/m&#xb7;day).

Composite semipermeable membrane, and production process thereof

A water-treating microbicide, containing an inorganic acid and a corrosion inhibitor, and further containing a carboxylic acid having 8 or less carbon atoms or any of alkali metal salts thereof. The present invention can provide a water-treating microbicide, water treatment method and water treatment apparatus exhibiting a high sterilization effect in a membrane separation device for seawater desalination, etc.

Bactericide for use in water treatment, method for water treatment and apparatus for water treatment

The present invention relates to the membrane treatment method for semipermeable membranes, that is, a method wherein it is characterized that not only remarkable improving effect of selective separation performance of semipermeable membranes is obtained but also durability of said improving effect for selective separation performance is improved by means of extremely simple and easy procedures such as said semipermeable membranes are successively brought into contact with very dilute of aqueous solutions including effective substances which are individually water-soluble in due order and for a short time, where said effective water-soluble substances form water-insoluble or very little water-soluble materials thereof fixed on the surface of said semipermeable membranes. The aforesaid remarkable effect is observed especially in the case of semipermeable membranes consisted of cross-linked polymers based of furfuryl alcohol including furfuryl alcohol as an essential monomer component, and polyamides, when, at the same time, the due combination of water-soluble amines and water-soluble aldehyde is employed as said aqueous solutions including effective water-soluble substances.

Membrane treatment method for semipermeable membranes

Growing community of inventors

Otsu, Japan

Katsufumi Oto