Multielement and morphological characterization of industrial waste incineration fly ash as studied by ICP-AES/ICP-MS and SEM-EDS

The leachabilities of major-to-ultratrace elements in industrial waste incineration fly ash (IWIFA) were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS) in order to characterize IWIFA. The leaching data of about 50 elements in the IWIFA sample could be obtained in the concentration range from mg g(-1) to sub-mug g(-1), when HNO3 and aqua regia were used as the leachants. In addition, morphological observations of IWIFA particles were performed by a scanning electron microscope with an energy dispersive X-ray spectrometer (SEM-EDS) before and after the leaching treatment of the IWIFA samples. From the data for the leaching and morphological observations, the chemical states of the elements in IWIFA were elucidated as follows: (i) core materials of fly ashes were mostly composed of stable oxides of major elements such as Si, Al, Ti, and Fe; (ii) Cu, Zn, Mo, Cd, and Bi were mainly adsorbed on the surface of fly ash particles in the forms of acid soluble compounds; (iii) Mn, Co, Ni, and Pb were partly taken into the core materials of fly ash particles, and partly adsorbed on the fly ash particles; and (iv) Sb, Cr, Sn, In, and W were contained as rather stable compounds in IWIFA.