Analytical Sciences

Chemical State Analysis of Heavy Metals and Radioactive Cesium in Municipal Solid Waste Incineration Fly Ash Contaminated with Radioactive Cesium Released by the FDNPP Accident

Yuya KOIKE,* Kengo FUJII,** Rintaro SAITO,** Narihito OGAWA,* and Atsushi OHBUCHI***

*Department of Applied Chemistry, School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama, Kawasaki, Kanagawa 214-8571, Japan
**Applied Chemistry Course, Graduate School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama, Kawasaki, Kanagawa 214-8571, Japan
***Rigaku Americas Corporation, 9009 New Trails Drive, The Woodlands, Texas, 77381, USA

The chemical states of heavy metals and radioactive Cs were estimated in fly ash sampled at Fukushima prefecture, Japan. Estimating the speciation of incinerator fly ash is important to ensure an appropriate and efficient management of fly ash generated from disaster-related waste. In this study, fly ash collected at a waste incineration facility in Fukushima prefecture was treated using a sequential extraction test. The test results indicated that the solubility behavior of radioactive Cs was similar to that of NaCl and KCl, and approximately 60% of radioactive Cs was included as water-soluble chloride compounds in the fly ash sample. Most heavy metals eluted in three fractions, in the extraction steps for carbonate-bound, free oxide, and bound to organic matter species. The chemical states of elements in the three non-water-soluble fractions and residue showed minimal elution into the environment. Therefore, most heavy metals in the fly ash exhibited minimal elution into the environment.

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