OXYANION SORPTION TO HIGH SURFACE AREA IRON AND ALUMINUM OXIDES

Authors: JOHNSTON, CLIFF - PURDUE UNIVERISITY; Goldberg, Sabine

Submitted to: American Chemical Society National Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/18/2006
Publication Date: 9/10/2006
Citation: Johnston, C.T., Goldberg, S.R. 2006. Oxyanion sorption to high surface area iron and aluminum oxides. American Chemical Society National Meeting, San Francisco, CA Sep 10-14,2006. Paper No. GEOC 63

Interpretive Summary:

Technical Abstract: Sorption of selected oxyanions (Mo, As, and P) to high surface area iron and aluminum oxides was investigated using in situ Raman and ATR-FTIR spectroscopy, batch sorption methods, electrophoretic mobility measurements, and surface complexation modeling. In situ ATR-FTIR and Raman spectra were coupled to chemical speciation modeling using spectral decomposition techniques to identify chemical species present in aqueous solution as a function of pH, ionic strength, and oxidation state. Coupled sorption-spectroscopic experiments were conducted using vibrational spectroscopy combined with batch sorption and electrophoretic mobility measurements. Surface spectroscopy confirmed that inner sphere surface complexes were involved for all three oxyanions. However, depending on the chemical composition of the aqueous phase (pH ionic strength and oxidation state), outer-sphere complexes were also found, and in some cases predominated. The spectroscopic data were used to provide input constraints to adapted surface complexation models.