Kabushiki Kasiha Toshiba

Hideki Shimada

Kenji Todori

Shuji Hayase

Nobutada Aoki

Naoki Tajima

Katsushi Nishizawa

Kazuo Unoki

The present invention is to clear the difficulty in determining the progress of the decomposition reaction of PCBs carried out by a conventional device for decomposing PCBs, and to provide a system for treating PCBs to render them harmless, capable of continuously determining the progress of the decomposition reaction of PCBs at real time by using a predetermined amount of a reaction solution taken out while the decomposition reaction of the PCBs is proceeding. The quantity of the polychlorobiphenyls existing in a polychlorobiphenyl-containing liquid can be determined by the system for treating polychlorobiphenyls to render them harmless according to the present invention in the following manner: a polychlorobiphenyl-containing liquid is irradiated with exciting light of from 400 nm to shorter than 450 nm, that can excite the polychlorobiphenyls, or with exciting light of from 300 nm to shorter than 400 nm, that can excite the decomposition products of the polychlorobiphenyls, and the intensity of the emitted light is measured at a wavelength between 450 nm and 600 nm, both inclusive; and the quantity of the existing polychlorobiphenyls is determined based on one of the values measured, or based on the ratio between the two values measured. The progress of the decomposition reaction of the polychlorobiphenyls can thus be determined, and the polychlorobiphenyls can be fully and sufficiently decomposed.

Growing community of inventors

Kawasaki, Japan

Hideki Shimada