Kentaro Miyawaki*, Nobutoshi Tanaka** and Toshihiko Matsuto**

* Department of Civil Engineering, Faculty of Engineering, Fukuoka University
** Department of Environmental and Sanitary Engineering, Faculty of Engineering, Hokkaido University

+ Correspondence should be addressed to Kentaro Miyawaki:
(8-19-1 Nanakuma, Johnan-ku, Fukuoka, 814-80 Japan)

Abstract

With increasing amounts of municipal solid waste treated by incineration, there is an increasing potential for environmental pollution by heavy metals from incinerator ash. The research team previously investigated and published on the fundamental condition (Temperature, pH, ORP, TOC) of biological sulfate reduction in incinerator ash leachate. In this paper, ash from 8 incinerators was studied to determine the influence of ash characteristics on sulfate reduction in ash leachate neutralized by CO2 injection. Also, influence of the inoculum source was studied.

Consequently, the following conclusions were obtained. 1) Considerable sulfate reduction occurred when the TOC in ash leachate was higher than 200mg/L. 2) When highly active inoculum was used, a quick and large sulfate reduction occurred. 3) The main process of sulfate reduction was incomplete lactate oxidation.

Key words: sulfate-reducing bacteria, municipal solid waste incinerator ash, insolubilization of heavy metal, leachate