Inorganic ligand effects on Pb(II) sorption to goethite ({alpha}-FeOOH). 2. Sulfate

Journal Article · Mon May 15 04:00:00 EDT 2000 · Journal of Colloid and Interface Science

DOI:https://doi.org/10.1006/jcis.1999.6702· OSTI ID:20080259

Ostergren, J D; Brown, Jr, G E; Parks, G A; Persson, P

The effects of sulfate anions on the uptake of Pb(II) onto goethite were investigated at the molecular level using in situ PbL{sub III}-EXAFS and ATR-FTIR spectroscopies. Macroscopic uptake data show that Pb uptake can be enhanced by at least 30% at pH 5 in the presence of 3.16 mM sulfate and that sulfate uptake at pH7 can be enhanced by more than a factor of 3 in the presence of 1.0 mM Pb. Consistent with behavior in sulfate-free systems, Pb(II) forms inner-sphere complexes sharing either corners or edges with Fe(O,OH){sub 6} octahedra under all conditions studied. The relative fraction of corner-sharing complexes is, however, significantly enhanced in the presence of sulfate at pH 5, 6 and 7 (all conditions studied) and additional sulfate species with C{sub 3v} or lower point symmetry were noted in the presence of Pb by ATR-FTIR. Drawing on bond valence and structural constraints developed in J.D. Ostergren et al. these results indicate formation of Type A ternary complexes bonded to the surface through Pb that is bound as a bridging bidentate complex to two adjacent A-type (singly coordinated) surface oxygens.

• Research Organization: Stanford Univ., CA (US)
• Sponsoring Organization: US Department of Energy
• DOE Contract Number: FG03-93ER14347
• OSTI ID: 20080259
• Journal Information: Journal of Colloid and Interface Science, Journal Name: Journal of Colloid and Interface Science Journal Issue: 2 Vol. 225; ISSN 0021-9797; ISSN JCISA5
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ENVIRONMENTAL TRANSPORT
GOETHITE
LEAD
LIGANDS
MOLECULAR STRUCTURE
SORPTION
SORPTIVE PROPERTIES
SULFATES