Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States). Physical and Life Sciences Directorate; Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States). Glenn T. Seaborg Institute
Pennsylvania State University, University Park, PA (United States)
Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States). Glenn T. Seaborg Institute
Minor actinides are major contributors to the long-term radiotoxicity of nuclear fuels and other radioactive wastes. Here in this context, understanding their interactions with natural chelators and minerals is key to evaluating their transport behavior in the environment. The lanmodulin family of metalloproteins is produced by ubiquitous bacteria and Methylorubrum extorquens lanmodulin (LanM) was recently identified as one of nature’s most selective chelators for trivalent f-elements. Herein, we investigated the behavior of neptunium, americium, and curium in the presence of LanM, carbonate ions, and common minerals (calcite, montmorillonite, quartz, and kaolinite). We show that LanM’s aqueous complexes with Am(III) and Cm(III) remain stable in carbonate-bicarbonate solutions. Furthermore, the sorption of Am(III) to these minerals is strongly impacted by LanM, while Np(V) sorption is not. With calcite, even a submicromolar concentration of LanM leads to a significant reduction in the Am(III) distribution coefficient (Kd, from >104 to ~102 mL/g at pH 8.5), rendering it even more mobile than Np(V). Thus, LanM-type chelators can potentially increase the mobility of trivalent actinides and lanthanide fission products under environmentally relevant conditions. Monitoring biological chelators, including metalloproteins, and their biogenerators should therefore be considered during the evaluation of radioactive waste repository sites and the risk assessment of contaminated sites.
Deblonde, Gauthier J.-P., et al. "Impact of a Biological Chelator, Lanmodulin, on Minor Actinide Aqueous Speciation and Transport in the Environment." Environmental Science and Technology, vol. 57, no. 49, Oct. 2023. https://doi.org/10.1021/acs.est.3c06033
Deblonde, Gauthier J.-P., Morrison, Keith, Mattocks, Joseph A., Cotruvo, Joseph A., Zavarin, Mavrik, & Kersting, Annie B. (2023). Impact of a Biological Chelator, Lanmodulin, on Minor Actinide Aqueous Speciation and Transport in the Environment. Environmental Science and Technology, 57(49). https://doi.org/10.1021/acs.est.3c06033
Deblonde, Gauthier J.-P., Morrison, Keith, Mattocks, Joseph A., et al., "Impact of a Biological Chelator, Lanmodulin, on Minor Actinide Aqueous Speciation and Transport in the Environment," Environmental Science and Technology 57, no. 49 (2023), https://doi.org/10.1021/acs.est.3c06033
@article{osti_2274879,
author = {Deblonde, Gauthier J.-P. and Morrison, Keith and Mattocks, Joseph A. and Cotruvo, Joseph A. and Zavarin, Mavrik and Kersting, Annie B.},
title = {Impact of a Biological Chelator, Lanmodulin, on Minor Actinide Aqueous Speciation and Transport in the Environment},
annote = {Minor actinides are major contributors to the long-term radiotoxicity of nuclear fuels and other radioactive wastes. Here in this context, understanding their interactions with natural chelators and minerals is key to evaluating their transport behavior in the environment. The lanmodulin family of metalloproteins is produced by ubiquitous bacteria and Methylorubrum extorquens lanmodulin (LanM) was recently identified as one of nature’s most selective chelators for trivalent f-elements. Herein, we investigated the behavior of neptunium, americium, and curium in the presence of LanM, carbonate ions, and common minerals (calcite, montmorillonite, quartz, and kaolinite). We show that LanM’s aqueous complexes with Am(III) and Cm(III) remain stable in carbonate-bicarbonate solutions. Furthermore, the sorption of Am(III) to these minerals is strongly impacted by LanM, while Np(V) sorption is not. With calcite, even a submicromolar concentration of LanM leads to a significant reduction in the Am(III) distribution coefficient (Kd, from >104 to ~102 mL/g at pH 8.5), rendering it even more mobile than Np(V). Thus, LanM-type chelators can potentially increase the mobility of trivalent actinides and lanthanide fission products under environmentally relevant conditions. Monitoring biological chelators, including metalloproteins, and their biogenerators should therefore be considered during the evaluation of radioactive waste repository sites and the risk assessment of contaminated sites.},
doi = {10.1021/acs.est.3c06033},
url = {https://www.osti.gov/biblio/2274879},
journal = {Environmental Science and Technology},
issn = {ISSN 0013-936X},
number = {49},
volume = {57},
place = {United States},
publisher = {American Chemical Society (ACS)},
year = {2023},
month = {10}}
