HR: 0830h
AN: B21C-0729    [PDF]
TI: Spectroscopic Studies of Competitive Adsorption Between Suwannee River Fulvic Acid (SRFA) and Various Low Molecular Weight (LMW) Organic Anions at Mineral -Water Interfaces
AU: * Yoon, T
EM: taeyoon@pangea.stanford.edu
AF: Stanford University, Surface & Aqueous Geochemistry Group, Department of Geological & Environmental Sciences, Stanford University, Stanford, CA 94305-2115 United States
AU: Johnson, S B
EM: stephen.johnson@stanford.edu
AF: Stanford University, Surface & Aqueous Geochemistry Group, Department of Geological & Environmental Sciences, Stanford University, Stanford, CA 94305-2115 United States
AU: Brown, G E
EM: gordon@pangea.stanford.edu
AF: Stanford University, Surface & Aqueous Geochemistry Group, Department of Geological & Environmental Sciences, Stanford University, Stanford, CA 94305-2115 United States
AU: Brown, G E
EM: gordon@pangea.stanford.edu
AF: Stanford Synchrotron Radiation Laboratory, SLAC, 2575 Sand Hill Rd., MS 69, Menlo Park, CA 94025 United States
AB: Natural Organic Matter (e.g., humic and fulvic acids) and LMW organic anions (e.g oxalate, maleate, and phthalate) are important components of natural soil and aquatic systems and play key roles in the transport and sequestration of trace metals due to their ability to form strong complexes with pollutant ions and/or positively charged mineral particle surfaces. Using in-situ ATR FTIR spectroscopy with flow-cell capability, we have investigated the competitive adsorption of SRFA for binding sites on the boehmite surface relative to various LMW organic anions forming inner-sphere (e.g., oxalate) or outer-sphere (e.g., maleate) surface complexes. At similar concentration ratios, inner-sphere oxalate surface complexes dominate boehmite surface binding sites with respect to outer-sphere surface complex-forming ligands such as fulvate and maleate. However, we also observed that outer-sphere type ligands (e.g., fulvic acid and maleate) with higher concentrations can induce desorption of inner-sphere oxalate surface complexes or inhibit inner-sphere oxalate surface complex formation.
DE: 0400 Biogeosciences
DE: 1055 Organic geochemistry
SC: Biogeosciences [B]
MN: 2003 Fall Meeting