Masaki Takaoka*, Junichi Takada**, Nobuo Takeda* and Takeshi Fujiwara*

*Department of Environmental Engineering, Graduate School of Engineering, Kyoto University
**Environmental Plant Engineering, Environmental Plant & Water Works Division, Nippon Steel Corporation

+ Correspondence should be addressed to Masaki Takaoka:
(Yoshidahon-machi, Sakyo-ku, Kyoto 606-8501 Japan)

Abstract

A microwave-assisted extraction (MAE) method was used in the extraction of PCBs and chlorobenzenes from municipal solid waste incinerator fly ash. The highest extraction efficiency was obtained at the conditions of: 120*C[Celsius degeree] of extraction temperature over 50 minutes of extraction time. At the most effective conditions, the efficiency and the precision of the MAE method were evaluated by comparing PCB and chlorobenzene levels to those of the soxhlet extraction and the supercritical fluid extraction (SFE) method, by using eight types of fly ash. MAE seems to be a viable alternative to soxhlet extraction and SFE. However, unburned carbon in the fly ash had a bad influence on the efficiency of the removal of PCBs and chlorobenzenes by MAE. The mutual relationship between chlorobenzenes and unburned carbon in fly ash was sufficiently estimated. As MAE has many advantages over soxhlet extraction, such as a shorter extraction time and a lower use of organic solvent, it is adequate for the extraction of PCBs and chlorobenzenes from fly ash.

Key words: microwave-assisted extraction, supercritical fluid extraction, PCBs, chlorobenzenes, fly ash