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Linking Solid Phase Speciation of Pb Sequestered to Birnessite to Oral Pb Bioaccessibility: Implications for Soil Remediation.
- Source :
-
Environmental Science & Technology . 2/1/2008, Vol. 42 Issue 3, p779-785. 7p. 3 Graphs. - Publication Year :
- 2008
-
Abstract
- 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 mat Pb kg-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. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 0013936X
- Volume :
- 42
- Issue :
- 3
- Database :
- Academic Search Index
- Journal :
- Environmental Science & Technology
- Publication Type :
- Academic Journal
- Accession number :
- 29990392
- Full Text :
- https://doi.org/10.1021/es071733n