Kohei Urano*, Chiduno Kimura*, Tsuyoshi Kobayashi

* Laboratory of Safety and Environmental Engineering, Yokohama National University

+ Correspondence should be addressed to Kohei Urano:
(79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501 Japan)

Abstract

Since some chlorinated solvents cause groundwater and air pollution, and destruction to the ozone layer, use of them has been regulated. Despite these regulation, they continue to use more than 200,000tons of solvents which include dichloromethane, trichloroethylene and tetrachloroethylene and so on. To decrease environmental pollution by chlorinated solvents, they must be recycled or decomposed by effective use of recycling and decomposing facilities. The number of recycling facilities, the quantity of recycled chlorinated solvents, recycling facility system, the number of decomposing facilities, the quantity of decomposed chlorinated solvents, and the decomposing facilities systems were investigated by means of a questionnaire and hearing. In 1995, 53,000tons of chlorinated solvents were recycled at 24 of the facilities owned by industrial waste management contractors, 9,500tons were decomposed at 34 of the facilities owned by industrial waste management contractors; and 13,500tons were decomposed at 6 facilities owned by makers of chlorinated solvents. Some dissolution facilities need to improve their systems to reduce polychlorinated dibenzodioxins and polychlorinated dibenzofrans.

Key words: chlorinated solvent, recycling facility, decomposing facility, industrial waste