Toray Industries, Inc.

Yohito Ito

Katsushige Yamada

Kenji Sawai

Hideki Sawai

Masateru Ito

Shin-ichi Minegishi

Seiko Kantani

Eri Shimizu

Yuichiro Nakaoki

Takashi Mimitsuka

Tamotsu Kitade

Yoshinari Fusaoka

Toshihiro Miyoshi

Takuhei Kimura

Masahiro Henmi

Kazunori Tomioka

Tetsu Yonehara

Hideaki Ando

Kyoya Takemoto

Shin-Ichi Minegishi

Provided is an effluent treatment method based on a membrane separation activated sludge method, the effluent treatment method being characterized in that activated sludge collected from a membrane separation activated sludge tank is observed by an optical means, image processing is performed, and effluent treatment conditions are controlled in accordance with the results thereof.

Effluent treatment method for membrane separation activated sludge, effluent treatment apparatus, and effluent treatment system management program

In a waste water treatment method using membrane separation-activated sludge, when, during filtration while supplying air using an immersion-type membrane separation unit loaded with multiple flexible membranes, the filtration differential pressure of the membranes at a set filtration flow rate exceeds a specified value Pwith respect to the filtration differential pressure Pof the initial period of operation, membrane filtration is continued with air supply stopped until the filtration differential pressure Pbecomes P&#x2265;P[kPa]. Then with the filtration flux or filtration pressure being smaller or negative compared to when filtering while supplying air, air is supplied and after the filtration differential pressure Pduring filtration reaches P&#x2264;P[kPa], filtration is returned to filtration while supplying air.

Waste water treatment method using membrane separation-activated sludge

The invention provides a method of producing a chemical product through continuous fermentation which includes filtering a culture of a microorganism or cultured cells with a separation membrane to recover a product from a filtrate and simultaneously retaining a nonfiltered fluid in, or refluxing it to, the culture, and adding fermentation materials to the culture, wherein a porous membrane having an average pore size of 0.01 &#x3bc;m or more to less than 1 &#x3bc;m is used as the separation membrane and the filtration is conducted with a transmembrane pressure difference in the range of 0.1 to 20 kPa. According to this method, the fermentation productivity of the chemical product can be largely elevated at high stability and a low cost.

Method of producing chemical product with continuous fermentation and filtering

A method of producing lactic acid by separating lactic acid produced in a culture solution by microbial fermentation, comprising: a step (A) of filtering the culture solution through a nano-filtration membrane; and a step (B) of distilling a lactic-acid-containing solution produced in step (A) under a pressure of 1 Pa to atmospheric pressure (inclusive) at a temperature of 25 to 200&#xb0; C. (inclusive) to recover lactic acid.

Lactic acid production method

A method of producing lactic acid by separating lactic acid produced in a culture solution by microbial fermentation, comprising: a step (A) of filtering the culture solution through a nano-filtration membrane; and a step (B) of distilling a lactic-acid-containing solution produced in step (A) under a pressure of 1 Pa to atmospheric pressure at a temperature of 25 to 200&#xb0; C. to recover lactic acid.

In the invention, the pipe lines around permselective membranes and the surfaces of permselective membranes are intermittently disinfected by adding an inexpensive acid such as sulfuric acid or the like to pre-treated crude water so as to make the water have a pH of 4 or lower. Accordingly, the invention provides a method of surely disinfecting the permselective membranes in membrane separation systems.

Method of bacteriostasis or disinfection for permselective membrane

Method for inhibiting growth of bacteria or sterilizing around separating membrane

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Shiga, Japan

Yohito Ito