Speciation of Zinc, Lead and Copper on Fly Ash by X-ray Photoelectron Spectroscopy

Masaki Takaoka*, Yasuhiro Kuramoto**, Nobuo Takeda* and Takeshi Fujiwara*
* Department of Environmental Engineering, Graduate School of Engineering, Kyoto University
** System Kankyo Keikaku Consultant Co. Ltd.
+ Correspondence should be addressed to Masaki Takaoka:
(Sakyo-ku, Kyoto, 606-8501, Japan)

Abstract
It is very important to know the dominant forms of heavy metals in fly ash generated from municipal solid waste incinerators or ash melting plants for consideration of detoxification and recycling. In this study, zinc, lead and copper in fly ash sampled in twenty municipal solid waste incinerators and five ash melting plants were analyzed using X-ray photoelectron spectroscopy. The dominant zinc compounds were 2ZnCO3¥3Zn (OH) 2 on the surface of fly ash and Zn or ZnO within the fly ash. PbCO3 and/or PbCl2 on the surface of fly ash were estimated. The chemical forms of copper did not depend on the fly ash type or depth and CuCl2 was not detected. Zinc and lead are therefore predominantly concentrated on the surface of fly ash.

Key words: zinc, lead, copper, fly ash, X-ray photoelectron spectroscopy