Fractionation of Suwannee River Fulvic Acid and Aldrich Humic Acid on α-Al2O3: Spectroscopic Evidence
Sorptive fractionation of Suwannee River Fulvic Acid (SRFA) and Purified Aldrich Humic Acid (PAHA) on a-Al2O3 at pH 6 was probed in the supernatant using different spectroscopic techniques. Comparison of dissolved organic carbon (DOC) analysis with UV/vis spectrophotometric measurements at 254 nm, including specific UV absorbance (SUVA) calculation, revealed a decrease in chromophoric compounds for the nonsorbed extracts after a 24 h contact time. This fractionation, only observable below a certain ratio between initial number of sites of humic substances and of a-Al2O3, seems to indicate a higher fractionation for PAHA. C(1s) near-edge X-ray absorption fine structure spectroscopy (NEXAFS) confirmed this trend and points to a decrease in phenolic moieties in the supernatant and to an eventual increase in phenolic moieties on the surface. Time-resolved luminescence spectroscopy (TRLS) of Eu(III) as luminescent probe showed a decrease in the ratio between the 5D0?7F2 and 5D0?7F1 transitions for the fractionated organic matter (OM) that is thought to be associated with a lower energy transfer from the OM to Eu(III) due to the loss of polar aromatics. These modifications in the supernatant are a hint for the modification of sorbed humic extracts on the surface.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
- Sponsoring Organization:
- Doe - Office Of Science
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 980214
- Report Number(s):
- BNL-93132-2010-JA; ESTHAG; TRN: US201015%%1599
- Journal Information:
- Environmental Science and Technology, Vol. 42, Issue 23; ISSN 0013-936X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Examination of Cadmium(II) Complexation by the Suwannee River Fulvic Acid Using 113Cd NMR Relaxation Measurements
Complexation of Cm(III)/Eu(III) with Silicate in Basic Solutions