Toray Industries, Inc.

Hitachi, Ltd.

Hiroo Takabatake

Yuji Tanaka

Masahide Taniguchi

Wakako Ogiwara

Kazuhiko Noto

Kotaro Kitamura

Koji Nakatsuji

Yusuke Okawa

Hirofumi Morikawa

Kentaro Kobayashi

Kazuya Sugita

Shigehisa Hanada

Atsushi Kitanaka

Kazuki Hagawa

Shinya Shimoda

Kenji Saito

Hironobu Suzuki

Yoshisuke Nakamura

The present invention relates to a damage inspection method for a reverse osmosis membrane, in which at least one of: presence or absence of physical damage; and a degree of physical damage in a reverse osmosis membrane is inspected based on presence or absence of a stained area on at least a permeate side of a stained membrane obtained by supplying a water-to-be-treated including a staining agent to the reverse osmosis membrane to stain the reverse osmosis membrane.

Method for inspecting damage in reverse osmosis membrane

An efficient method is provided for cleaning hollow fiber membrane modules, the method being capable of efficiently removing substances accumulated inside hollow fiber membrane modules. The internal liquid on the raw liquid side of the hollow fiber membrane module () is discharged from a lower end face nozzle () of the hollow fiber membrane module () while air-cleaning is performed. The method for cleaning hollow fiber membrane modules is characterized in that the rate of liquid discharge from the lower end face nozzle of the hollow fiber membrane module () when discharging the internal liquid from the lower end face nozzle is adjusted so that the air supplied from the lower end face nozzle of the hollow fiber membrane module () through the aeration holes is supplied to the hollow fiber membrane module ().

Method for cleaning hollow fiber membrane module

Provided is a fresh water generation system which filters biotreated water produced by microbiologically treating waste water via a primary semi-permeable membrane (), and then mixes concentrated water rejected by the filtration with seawater, thereby to filter the mixed water via a secondary semi-permeable membrane (). This system enables frequencies of chemical cleaning and replacement of the secondary semi-permeable membrane to be reduced. The fresh water generation system comprises: a primary semi-permeable membrane apparatus () which separates microorganism treating waste water into permeated water and concentrated water; a secondary semi-permeable membrane apparatus () which filters mixed water prepared by mixing the concentrated water into seawater. In the fresh water generation system, the primary semi-permeable membrane () has an equal to or a higher microorganism adhesive property than the secondary semi-permeable membrane ().

Fresh water generation system

Provided is a fresh water production method applying a combined water-treatment technology employing a plurality of semi-permeable membrane units, the method enabling prevention of problems caused by growth of a biofilm and allowing effective use of an injected chemical agent and an injected neutralizing agent. The fresh-water production method produces fresh water by treatment of source water by a semi-permeable membrane treatment device, the concentrated water resulting from the treatment by the semi-permeable membrane treatment device is mixed with other source water, and the water mixture is treated by a second semi-permeable membrane treatment device. A first chemical agent is injected continuously or intermittently into the source water and a second chemical agent is injected continuously or intermittently into the source water.

Fresh water production method

A water producing system which is provided with a semi-permeable membrane treatment process Ato produce membrane permeate Aand concentrate A, a semi-permeable membrane treatment processBwhich is equipped with a treatment target water B branching means for branching treatment target water Binto two or more to produce a membrane Band concentrate B, and a semi-permeable membrane treatment process Cwhich is equipped with a first water mixing means for mixing one of the treatment target water B with at least part of the concentrate A, and subjects the mixed water to the semi-permeable membrane treatment to produce membrane permeate Cand concentrate C, thereby producing fresh water from a plurality of kinds of raw water which differ in osmotic pressure.

Water producing system and operation method therefor

Disclosed is a fresh water generator for fresh water production, which is effective to prevent a membrane life from becoming worse by suppressing the load on the membrane of a second semi-permeable membrane treatment facility when the concentrated water produced by the treatment of a first semi-permeable membrane treatment facility, and water to be treated with different osmotic pressure there from are mixed and treated with the second semi-permeable membrane treatment facility by the fresh water generator which comprises a means for storing the concentrated water produced from the first semi-permeable membrane treatment facility and water (B) to be treated, which is separately supplied in a storage tank A and a storage tank B in such a manner that the flow rate (mixture ratio) of the concentrated water to the water (B) to be treated is maintained constant, and supplying the concentrated water and the water (B) to be treated from each of the storage tanks to the second semi-permeable membrane treatment facility at a predetermined flow rate in at least a treatment process for treating water (A) to be treated with the first semi-permeable membrane treatment facility so as to obtain fresh water.

Fresh water generator

A fine bubble diffusing tube that can generate fine bubbles evenly and uniformly even when the diffusing tube has a long length, a fine bubble diffusing device using such a tube and a submerged membrane separation apparatus are produced. The fine bubble diffusing tube is provided with a cylindrical supporting tube, and an elastic sheetwith fine slits formed therein, with the elastic sheetbeing placed to cover the outer circumference of the supporting tube, so that, upon supplying a gas to a space between the elastic sheetand the supporting tube, the fine slits of the elastic sheetare opened to generate fine bubbles, and the supporting tubehas a length L of 1000 mm or more in the longitudinal direction, with gas supply unitsserving as gas flow inlets being attached to the two ends of the supporting tube.

Fine bubble diffusing pipe, fine bubble diffusing apparatus, and submerged membrane separation apparatus

A method is provided for precisely predicting the temporal variation of a membranous filtration resistance, a transmembrane pressure, a membranous filtration flowrate, or a membranous filtration flowrate as occurs in filtrating a liquid with a membrane, in a membranous filtration method wherein the liquid is filtrated by the separation membrane with the transmembrane pressure as a driving force. The method includes calculating: a constituent component quantity value of the liquid that attaches on a surface of the separation membrane at a time t+&#x394;t; a constituent component quantity value of the liquid that exists in pores of the separation membrane; a consolidation degree of a constituent component of the liquid that attaches on the separation membrane surface; a membranous filtration resistance value; a transmembrane pressure value; and a membranous filtration flowrate value.

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Otsu, Japan

Hiroo Takabatake