Investigating the Speciation of Copper in Secondary Fly Ash by X-ray Absorption Spectroscopy

Abstract

Although some researchers have reported that chlorides may play an important part in the evaporation of copper during heat treatment of municipal solid waste incinerators (MSWI) fly ash (1, 2) , details on the copper speciation in volatile matters (secondary fly ash, SFA) are still lacking. In this work, we used in situ X-ray absorption spectroscopy (XAS) experiments involving three types of SFA, which was collected from a high-temperature tubular electric furnace by thermal treatment of municipal solid waste incinerator (MSWI) fly ash at 1000, 1150, and 1250 degrees C. The results obtained by a linear combination fit (LCF) of X-ray absorption near edge structure (XANES) spectra revealed that in MSWI fly ash copper mainly exists as CuO and CuSO(4).5H(2)O while chloride almost dominated all the content of the SFA conformation, which was more than 80%. Extended X-ray absorption fine structure (EXAFS) data analysis indicated the presence of both Cu-O and Cu-Cl bonds in the first coordination shell of Cu ions in all SFA, while only Cu-O bonds occur in the MSWI fly ash. Consequently, in the MSWI fly ash during heat treatment copper evaporated as chloride, and the latter plays an important role in the formation of copper chloride.

RETRACTED: Competitive sorption and selective sequence of Cu(II) and Ni(II) on montmorillonite: Batch, modeling, EPR and XAS studies

“…In this study, the spectral characteristics of the Cu(II)-containing samples (Electronic Annex, Figure S1A) suggest that Cu is present in the +2 oxidation state (Palomino et al, 2000;Furnare et al, 2005a;Strawn and Baker, 2009;Tian et al, 2009). To further identify the detailed microstructures of Cu(II) in the sorption samples, the normalized XANES spectra were processed to produce their first derivative curves (Electronic Annex, Figure S1B).…”

Enhanced photocatalytic degradation of sulfamethoxazole by visible-light-sensitive TiO2 with low Cu addition

“…2, the XENAS spectra of metallic Cu, Cu 2 O and CuO standards show the white line peaks at 8991.7, 8993.4 and 8995.6 eV, respectively, which correspond to 1s ? 4p transitions [30,31]. The Cu-TiO 2 shows a broad white line peak at 8993.5-8997.8 eV, suggesting the Cu species is mainly deposited in the 2+ state.…”

Removal of toxic and alkali/alkaline earth metals during co-thermal treatment of two types of MSWI fly ashes in China

“…Hsiao et al (2006) revealed that CuCl 2 , Cu(OH) 2 and CuO with a small amount of CuS were major copper compounds in fly ashes. According to Tian et al (2009), the copper in raw fly ash mainly existed as CuO and CuSO 4 Á5H 2 O, while copper chloride dominated all the content of fly ash at 1000°C. Even though copper species in MSWI fly ash was not identified, it seems Cu mainly vaporized in the form of chloride and higher temperatures accelerated the formation of copper chlorides (Belevi and Langmeier, 2000).…”