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(70-19) Leaching characteristics and bioavailability of heavy metals from landfill disposal site. Ono, Yoshiro1, Yamada, Aya*,1, Toda, Yoshinori1, Kida, Akiko2, 1 University of Okayama, 3-1-1, Tsushima-naka, Okayama, Japan2 National Institute for Environmental Studies, 16-2, Onogawa, Tsukuba, Japan ABSTRACT- In order to assess the water quality of leachate from the landfill site of waste disposal, the content of heavy metals of leachate and fly ashes were investigated. The evaluation was conducted by field survey, leaching test from fly ashes disposed to landfill site and the bioavailability of heavy metals to aquatic living organism. 1) Some of heavy metals such as lead, cadmium etc. are determined more hazardous as discharged substances from waste proposed by the PBT′s list of US.EPA. In this research, multiple regression analysis was applied to the obtained data from a landfill site and river water during 1 year to identify those sources of the heavy metals. 2) Leaching characteristics of fly ashes were investigated on the following factors; pH, a liquid/solid ratio and ionic strength. Leaching of some heavy metals was found to be depended on pH and ionic strength such as cadmium. 3) A bioavailability test based on direct intake of mammals and medaka (Oryzias latipes) as a typical fish in fresh water in Japan were conducted on the hazardous heavy metals. Key words: Bioavailability, heavy metals, disposal site, multiple regression analysis |
