Effect of hydroxamate siderophores on Fe release and Pb(II) adsorption by goethite

Autor(en)

Stephan Krämer, Sing-Foong Cheah, R Zapf, Jing-Jun Xu, Kenneth N. Raymond, Garrison Sposito

Abstrakt

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.

Organisation(en)

Externe Organisation(en)

University of California, Berkeley, Nankai University

Journal

Geochimica et Cosmochimica Acta

Band

63

Seiten

3003-3008

Anzahl der Seiten

6

ISSN

0016-7037

Publikationsdatum

1999

Peer-reviewed

Ja

ÖFOS 2012

105904 Umweltforschung

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/effect-of-hydroxamate-siderophores-on-fe-release-and-pbii-adsorption-by-goethite(fae2e889-549e-4af1-a9a6-42e0395c52bd).html