TY - JOUR
T1 - Effect of hydroxamate siderophores on Fe release and Pb(II) adsorption by goethite
AU - Krämer, Stephan
AU - Cheah, Sing-Foong
AU - Zapf, R
AU - Xu, Jing-Jun
AU - Raymond, Kenneth N.
AU - Sposito, Garrison
N1 - DOI: 10.1016/S0016-7037(99)00227-6
Affiliations: Division of Ecosystem Sciences, University of California, 94720-3110, Berkeley, CA, United States; Department of Chemistry, University of California, 94720-1460, Berkeley, CA, United States
Adressen: Krämer, S.M.; University of California, Berkeley; 235 Hilgard Hall Berkely, CA 94720, United States; email: sKrä[email protected]
Source-File: 533Scopus090408.csv
Import aus Scopus: 2-s2.0-0033379762
Importdatum: 15.04.2008 15:59:36
PY - 1999
Y1 - 1999
N2 - Hydroxamate siderophores are biologically-synthesized, Fe(III)-specific ligands which are common in soil environments. In this paper, we report an investigation of their adsorption by the iron oxyhydroxide, goethite; their influence on goethite dissolution kinetics; and their ability to affect Pb(II) adsorption by the goethite surface. The siderophores used were desferrioxamine B (DFO-B), a fungal siderophore, and desferrioxamine, D1, an acetyl derivative of DFO-B (DFO-D1). Siderophore adsorption isotherms yielded maximum surface concentrations of 1.5 (DFO-B) or 3.5 (DFO-D1) ?mol/g at pH 6.6, whereas adsorption envelopes showed either cation-like (DFO-B) or ligand-like (DFO-D1) behavior. Above pH 8, the adsorbed concentrations of both siderophores were similar. The dissolution rate of goethite in the presence of 240 ?M DFO-B or DFO-D1 was 0.02 or 0.17 ?mol/g hr, respectively. Comparison of these results with related literature data on the reactions between goethite and acetohydroxamic acid, a monohydroxamate ligand, suggested that the three hydroxamate groups in DFO-D1 coordinate to Fe(III) surface sites relatively independently. The results also demonstrated a significant depleting effect of 240 ?M DFO-B or DFO-D1 on Pb(II) adsorption by goethite at pH > 6.5, but there was no effect of adsorbed Pb(II) on the goethite dissolution rate.
AB - Hydroxamate siderophores are biologically-synthesized, Fe(III)-specific ligands which are common in soil environments. In this paper, we report an investigation of their adsorption by the iron oxyhydroxide, goethite; their influence on goethite dissolution kinetics; and their ability to affect Pb(II) adsorption by the goethite surface. The siderophores used were desferrioxamine B (DFO-B), a fungal siderophore, and desferrioxamine, D1, an acetyl derivative of DFO-B (DFO-D1). Siderophore adsorption isotherms yielded maximum surface concentrations of 1.5 (DFO-B) or 3.5 (DFO-D1) ?mol/g at pH 6.6, whereas adsorption envelopes showed either cation-like (DFO-B) or ligand-like (DFO-D1) behavior. Above pH 8, the adsorbed concentrations of both siderophores were similar. The dissolution rate of goethite in the presence of 240 ?M DFO-B or DFO-D1 was 0.02 or 0.17 ?mol/g hr, respectively. Comparison of these results with related literature data on the reactions between goethite and acetohydroxamic acid, a monohydroxamate ligand, suggested that the three hydroxamate groups in DFO-D1 coordinate to Fe(III) surface sites relatively independently. The results also demonstrated a significant depleting effect of 240 ?M DFO-B or DFO-D1 on Pb(II) adsorption by goethite at pH > 6.5, but there was no effect of adsorbed Pb(II) on the goethite dissolution rate.
M3 - Article
SN - 0016-7037
VL - 63
SP - 3003
EP - 3008
JO - Geochimica et Cosmochimica Acta
JF - Geochimica et Cosmochimica Acta
IS - 19-20
ER -