Linking Solid Phase Speciation of Pb Sequestered to Birnessite to Oral Pb Bioaccessibility: Implications for Soil Remediation

Journal Article · Mon Jun 30 04:00:00 EDT 2008 · Environ. Sci. Technol.

DOI:https://doi.org/10.1021/es071733n· OSTI ID:1006512

Beak, Douglas G; Basta, Nicholas T; Scheckel, Kirk G; Traina, Samuel J ^[1]

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1. EPA

Lead (Pb) sorption onto oxide surfaces in soils may strongly influence the risk posed from incidental ingestion of lead-contaminated soils. In this study, Pb was sorbed to a model soil mineral, birnessite, and was placed in a simulated gastrointestinal tract (in vitro) to simulate the possible effects of ingestion of a soil contaminated with Pb. The changes in Pb speciation were determined using extended X-ray absorption fine structure and X-ray absorption near edge spectroscopy. Birnessite has a very high affinity for Pb with a sorption maximum of 0.59 mol Pb kg{sup -1} (approximately 12% Pb sorbed by mass) in which there was no detectable bioaccessible Pb (<0.002%). Surface speciation of the birnessite Pb was determined to be a triple corner sharing complex in the birnessite interlayer. Lead sorbed to Mn oxide in contaminated media will have a very low (? 0) Pb bioaccessibility and present little risk associated with incidental ingestion of soil. These results suggest that birnessite, and other Mn oxides would be powerful remediation tools for Pb-contaminated media because of their high affinity for Pb.

• Research Organization: Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
• Sponsoring Organization: USDOE
• OSTI ID: 1006512
• Journal Information: Environ. Sci. Technol., Journal Name: Environ. Sci. Technol. Journal Issue: (3) ; 2008 Vol. 42; ISSN ESTHAG; ISSN 0013-936X
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

54 ENVIRONMENTAL SCIENCES
ABSORPTION
AFFINITY
FINE STRUCTURE
GASTROINTESTINAL TRACT
HAZARDS
INGESTION
LEAD
MASS
OXIDES
SOILS
SOLIDS
SORPTION
SPECTROSCOPY
SURFACES