HR: 0830h
AN: B41D-0928    [PDF]
TI: Effects of Siderophores on Metal Adsorption to Kaolinite
AU: * Hepinstall, S E
EM: shepinst@nd.edu
AF: University of Notre Dame, Department of Civil Engineering and Geological Sciences, 152A Fitzpatrick Hall of Engineering, Notre Dame, IN 46556 United States
AU: Maurice, P A
EM: pmaurice@nd.edu
AF: University of Notre Dame, Department of Civil Engineering and Geological Sciences, 152A Fitzpatrick Hall of Engineering, Notre Dame, IN 46556 United States
AU: Miller, M J
EM: mmiller1@nd.edu
AF: University of Notre Dame, Department of Chemistry and Biochemistry, Stepan Chemistry Hall, Notre Dame, IN 46556 United States
AB: Siderophores are metal-complexing ligands with high affinities for Fe(III), produced by many microorganisms in Fe-deficient environments. Siderophores can also form strong complexes with other metals such as Pb and Cd; hence, siderophores may play an important role in controlling metal mobility in porous media. This study compared the effects of siderophores desferrioxamine-B (DFO-B), desferrioxamine-D (DFO-D1), desferrioxamine-E (DFO-E), as well as siderophore-like ligand acetohydroxamic acid (aHA) on Pb and Cd adsorption to kaolinite (KGa-1b) at pH 4.5 to 9, in 0.1 M NaClO$_{4}$, at 22 \deg C, in the dark. At pH $>$ 6.5 all of the siderophores plus aHA, inhibited Pb adsorption, with inhibition increasing in the order aHA $<$ DFO-D1 $<$ DFO-B $<$ DFO-E. At lower pH, all four ligands slightly enhanced Pb adsorption. These ligands also inhibited Cd adsorption at high pH, but had little or no effect at low pH. These results suggest that siderophore effects on metal mobility through porous media are likely to be complex and variable with pH.
DE: 1065 Trace elements (3670)
SC: Biogeosciences [B]
MN: 2003 Fall Meeting