Yasuo Horii*, Soutaro Higuchi**, Takayuki Shimaoka*** and Masataka Hanashima****

* KUBOTA Corporation
** General Manager, Environmental Facilities Dept., JAPAN ENGINEERING CONSULTANTS Co.,Ltd.
*** Faculty of Engineering, Fukuoka University
**** Department of Civil Eng.,Fuculty of Eng., Fukuoka University

+ Correspondence should be addressed to Yasuo Horii:
(2-47 shikituhigashi, 1-chome, Naniwa-ku Osaka, 556 Japan)

Abstract

In recent years, Japan's incineration techniques have been considerably improved to quantitatively reduce and qualitatively stabilize refuse produced in a variety of consumer activities. At the same time, however, as incineration has become more advanced, more incineration residue characterized by small ignition loss is buried in more final disposal sites, resulting in a higher concentration of inorganic salts contained in incineration residue and landfill leachate. The concentration of calcium and chlorine in leachate has risen in particular, resulting in problems such as scale in water treatment facilities and salt problems in areas where leachate is discharged. To solve the problems caused by inorganic salts, the authors have undertaken studies to develop techniques to mitigate the adverse effects of calcium contained in leachate and remove salts from leachate.

Key words: leachate treatment, calcium scale control, desalination technology, electrodialysis, reusing inorganic salts.