Asahi Kasei Kogyo Kabushiki Kaisha

Asahi Kasei Kabushiki Kaisha

Takehiko Otoyo

Tohru Taniguchi

Nobuhiko Suga

Hiroyuki Arai

Kazuo Toyomoto

Noboru Kubota

Tomotaka Hashimoto

Hiroki Takezawa

Kazuto Nagata

A membrane distillation device, provided with a membrane distillation module including a plurality of hydrophobic porous hollow fiber membranes, and a condenser for condensing water vapor extracted from the module. The average pore diameter of the porous hollow fiber is 0.01-1 &#x3bc;m. The filling ratio of the porous hollow fiber of the membrane distillation module is 10-80%, and the pressure condition for the membrane distillation is equal to or greater than 1 kPa and equal to or less than the saturated vapor pressure of water at the temperature of the water being treated.

Porous membrane for membrane distillation, and method for operating membrane distillation module

A method and apparatus for purifying an aqueous suspension comprising feeding an aqueous suspension containing fine particles comprising an inorganic component from the outer surface of a wavy hollow fiber membrane having an outer diameter of from 0.5 to 3.1 mm to filter, followed by physical wash of the hollow fiber membrane. The purifying method can reduce the damage of the membrane outer surface during the physical wash step, prevent open pores on the surface from covering and achieve stable filtration. The hollow fiber membrane bundle can be produced by having a pulsation flow contacted with the hollow fiber material being extruded from the double spinning nozzle under specific conditions and cooling and solidifying or coagulating it while shaking.

Method for purifying aqueous suspension

A method for simultaneously removing a plurality of different heavy metal ions from contaminated water is disclosed. A plurality of different heavy metal ions can be simultaneously, efficiently removed by filtering contaminated water through a porous membrane comprising a membranous, porous resin matrix and a plurality of side chains chemically bound to both surfaces and pore wall surfaces of the matrix, which side chains each have a chelate group, preferably an iminodiacetic acid group, and terminating the filtration when the concentration of a determinant heavy metal ion in the filtrate reaches a predetermined level. By the method of the present invention, a plurality of different heavy metal ions, such as a cobalt ion and a nickel ion, can be simultaneously, efficiently removed from contaminated water, such as water to be used for and waste water from a nuclear power generator, on a commercial scale.

Method for removing heavy metal ions from contaminated water and a

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Fuji, Japan

Takehiko Otoyo