【Paper】
Behavior of Mercury in Disposed Dry Batteries after 10 Years in Landfill Site
Ryuji Yanase*, Fumiaki Hirano*, Yasushi Matsufuji* and Masataka Hanashima**
* Department of Civil Engineering, Faculty of Engineering, Fukuoka University
** Fukuoka Research Center for Recycling Systems
† Correspondence should be addressed to Ryuji Yanase:
Department of Civil Engineering, Faculty of Engineering, Fukuoka University
（8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180 Japan）

Abstract
The disposal of used dry batteries containing mercury in Japan led to fears of environmental contamination by mercury, becoming a major social issue in 1983. Many of the details of the behavior and characteristics of mercury from landfilled dry batteries are yet unknown.
This paper discusses an investigation of mercury leakage into the leachate and vaporization into the atmosphere, using a large-scaled lysimeter. The lysimeter was disassembled 10 years after the landfill was started, and the behavior of mercury inside the lysimeter investigated.
Results indicate that total mercury leaking into leachate over the 10-year period was no more than 0.1％, and atmospheric dispersion no more than 2％. Disposal（vaporization）into the atmosphere through outgassing was therefore more important in the release of mercury into the environment. Mercury was found to have transferred from the dry batteries to the waste layers. Over 90％ of the original mercury content remained in the landfill after the 10-year period, confirming that the substance does not leak into the landfill site easily.

Key words: landfill site, dry battery, vaporized mercury, mass balance of mercury, leachate