XAFS Studies of Nickel And Sulfur Speciation in Residual Oil Fly-Ash Particulate Matters (ROFA PM)

Journal Article · Thu Jul 12 04:00:00 EDT 2007 · Environ. Sci. Tech. 41:1104,2007

DOI:https://doi.org/10.1021/es061635m· OSTI ID:909752

Pattanaik, S; Huggins, F E; Huffman, G P; Linak, W P; Miller, C A

XAFS spectroscopy has been employed to evaluate the effect of fuel compositions and combustion conditions on the amount, form, and distribution of sulfur and nickel in size-fractionated ROFA PM. Analysis of S K-edge XANES establish that sulfate is abundant in all PM. However, depending upon the combustion conditions, lesser amounts of thiophenic sulfur, metal sulfide, and elemental sulfur may also be observed. Least-squares fitting of Ni K-edge XANES reveals that most of the nickel in PM is present as bioavailable NiSO{sub 4}.nH{sub 2}O. The insoluble Ni mainly exists as a minor species, as nickel ferrite in PM{sub 2.5} (PM < 2.5 {micro}m) and nickel sulfide, NixSy in PM{sub 2.5+} (PM > 2.5 {micro}m). The Ni K-edge XANES results are in agreement with the EXAFS data. Such detailed speciation of Ni and S in PM is needed for determining their mobility, bioavailability, and reactivity, and hence, their role in PM toxicity. This information is also important for understanding the mechanism of PM formation, developing effective remediation measures, and providing criteria for identification of potential emission sources. Transition metals complexing with sulfur is ubiquitous in nature. Therefore, this information on metal sulfur complex can be critical to a large body of environmental literature.

• Research Organization: Stanford Linear Accelerator Center (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 909752
• Report Number(s): SLAC-REPRINT-2007-138
• Journal Information: Environ. Sci. Tech. 41:1104,2007, Journal Name: Environ. Sci. Tech. 41:1104,2007 Vol. 41; ISSN ESTHAG; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
CHEMICAL COMPOSITION
CHEMICAL STATE
COMBUSTION PRODUCTS
FLY ASH
NICKEL COMPOUNDS
Other
OTHER
PARTICULATES
RESIDUAL FUELS
SULFUR COMPOUNDS
TOXICITY