Hitachi, Ltd.

Setsuo Saitou

Tetsuo Yamaguchi

Norio Shimizu

Kazuaki Ichihashi

Youji Odawara

Toshimi Mukushi

Azuma Nakaoka

Yooji Odawara

Masao Ueno

Gel beads of microbial cells or enzymes enclosed in gels are produced by forming a surface liquid stream of a gelling agent flowing from the center toward the peripheral wall of a vessel containing the gelling agent by a lower rotor on the liquid surface of the gelling agent, and dispersing a colloidal suspension of microbial cells or enzymes into a droplets by an upper rotor and allowing the dispersed droplets to fall onto the surface liquid stream, thereby contacting the droplets with the gelling agent. The lower and upper rotors may have vanes radially provided at a periphery of a lower and upper sides, respectively. In place of separate rotors, a single rotor may be used with lower and upper surfaces which respectively provide the functions of the lower and upper rotors. The lower and upper surfaces may also have radially provided vanes. The lower and upper rotors or the lower and upper surfaces of a single rotor are spaced sufficiently from each other so that gelling agent is not splashed by the lower rotor or surface onto the upper rotor at surface. The bead size of gel beads can be adjusted by adjusting the number of revolutions of the rotor, and gel beads of smaller bead size can be produced in a mass production scale without any problem of nozzle clogging and without using a number of nozzles of smaller size.

Apparatus and process for producing gel beads of microbial cells or

Cultivation of microorganisms is controlled by measuring a pressure in a cultivation tank, a flow rate of effluent gas from the cultivation tank, and a concentration of carbon dioxide gas in the effluent gas, calculating a partial pressure of carbon dioxide gas in the cultivation tank and an amount of a carbon dioxide gas produced by the microorganisms, calculating an amount of propagated microorganism cells from the resulting partial pressure of carbon dioxide gas and the amount of produced carbon dioxide gas, thereby calculating an amount of microorganism cells in culture liquor, and supplying a substrate in an amount controlled in accordance with the resulting amount of microorganism cells in culture liquor. Microorganisms can be cultivated in high yield and at a high product concentration.

Process and apparatus for controlling cultivation of microorganisms

Waste water containing organic materials is introduced into an aeration tank, and is subjected to aeration treatment in the presence of activated sludge, while supplying oxygen to the aeration tank. The tank provided with an air diffusion pipe at the bottom of the tank, an air dispersion device above the air diffusion pipe and a plurality of inside cylinders above the air dispersion device. An overall circulating stream and partial circulating streams are generated in the aeration tank.

Apparatus for high-efficient microbiological oxidation treatment

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Hitachi, Japan

Setsuo Saitou