Bioaccumulation of metals by lichens: Uptake of aqueous uranium by Peltigera membranacea as a function of time and pH

Haas, Johnson R.; Bailey, Elizabeth H.; William Purvis, O.

Abstract

Uranium sorption experiments were carried out at ∼25 °C using natural samples of the lichen Peltigera membranacea. Thalli were incubated in solutions containing 100 ppm U for up to 24 h at pH values from 2 to 10. Equilibrium sorption was not observed at less than ∼6 h under any pH condition. U sorption was strongest in the pH range 4-5, with maximum sorption occurring at a pH of 4.5 and an incubation time of 24 h. Maximum U uptake by P. membranacea averaged ∼42 000 ppm, or ∼4.2 wt% U. This appears to represent the highest concentration of biosorbed U, relative to solution U activity, of any lichen reported to date. Investigation of post-experimental lichen tissues using electron probe microanalysis (EPM) reveals that U uptake is spatially heterogeneous within the lichen body, and that U attains very high local concentrations on scattered areas of the upper cortex. Energy dispersive spectroscopic (EDS) analysis reveals that strong U uptake correlates with P signal intensity, suggesting involvement of biomass-derived phosphate ligands or surface functional groups in the uptake process.

Citation

Haas, J. R., Bailey, E. H., & William Purvis, O. (1998). Bioaccumulation of metals by lichens: Uptake of aqueous uranium by Peltigera membranacea as a function of time and pH. American Mineralogist, 83(11-12 Part 2), 1494-1502. https://doi.org/10.2138/am-1998-11-1237

• Journal Article Type: Article
• Online Publication Date: Mar 2, 2017
• Publication Date: Dec 1, 1998
• Deposit Date: Apr 25, 2021
• Journal: American Mineralogist
• Print ISSN: 0003-004X
• Publisher: Mineralogical Society of America
• Peer Reviewed: Peer Reviewed
• Volume: 83
• Issue: 11-12 Part 2
• Pages: 1494-1502
• DOI: https://doi.org/10.2138/am-1998-11-1237
• Public URL: https://nottingham-repository.worktribe.com/output/5160874
• Publisher URL: https://pubs.geoscienceworld.org/msa/ammin/article-abstract/83/11-12_Part_2/1494/43397/Bioaccumulation-of-metals-by-lichens-uptake-of?redirectedFrom=fulltext