Hiroshi Fukui*, Toshiro Sakurai*, Nobuo Awaji*, Naoyuki Harabayashi**,Tomiharu Ito** and Yukio Kojima*

* Kanagawa Environmental Research Center
** Hatano Research Institute, Food and Drug Safety Center

+ Correspondence should be addressed to Hiroshi Fukui:
(842 Shimojuku, Nakahara, Hiratsuka, Kanagawa 254 Japan)

Abstract

Synthetic rubber sheets used for seepage control in landfills were extracted with water, and organic substances in the extract were studied. The compounds given below were identified in the extract; benzothiazole, cyclohexyl isothiocyanate, 2-benzothiazolol, N,N'-dicyclohexylurea and 2-mercaptobenzothiazole. On the other hand, when it was checked whether these compounds were in leachate from landfills, 2-benzothiazolol and N,N'-dicyclohexylurea were detected in leachate from landfills containing plastic and rubber wastes. It is therefore considered that both species extracted from the waste and the synthetic rubber sheets themselves could be included in these two compounds. Next, peaks on GC chromatograms of leachate from landfills were further examined, and it was shown that N-buthylbenzensulfonamide was also in leachate. In addition, since little is known concerning biological activity of 2-benzothiazolol, a decomposition product of 2-mercaptobenzothiazole, the two compouds were subjected to reverse mutation test in bacteria; but both were negative.

Key words: final disposal site, leachate, synthetic rubber sheets, leaching test, vulcanization accelerator