Abstract Details
(2020) The Role of Uranium Speciation in its Isotopic Fractionation
Bernier-Latmani R, Brown A, Pan Z, Faisova R, Sato A, Roebbert Y, Vitova T, Mazzanti M, Abe M & Weyer S
https://doi.org/10.46427/gold2020.177
The author has not provided any additional details.
08b: Room 3, Monday 22nd June 22:00 - 22:03
Rizlan Bernier-Latmani
View all 4 abstracts at Goldschmidt2020
View abstracts at 16 conferences in series
Ashley Brown View all 2 abstracts at Goldschmidt2020 View abstracts at 6 conferences in series
Zezhen Pan View all 3 abstracts at Goldschmidt2020 View abstracts at 3 conferences in series
Radmila Faisova
Ataru Sato View all 2 abstracts at Goldschmidt2020 View abstracts at 3 conferences in series
Yvonne Roebbert View all 2 abstracts at Goldschmidt2020 View abstracts at 8 conferences in series
Tonya Vitova View all 3 abstracts at Goldschmidt2020 View abstracts at 4 conferences in series
Marinella Mazzanti View all 2 abstracts at Goldschmidt2020 View abstracts at 3 conferences in series
Minori Abe View all 2 abstracts at Goldschmidt2020 View abstracts at 4 conferences in series
Stefan Weyer View all 6 abstracts at Goldschmidt2020 View abstracts at 21 conferences in series
Ashley Brown View all 2 abstracts at Goldschmidt2020 View abstracts at 6 conferences in series
Zezhen Pan View all 3 abstracts at Goldschmidt2020 View abstracts at 3 conferences in series
Radmila Faisova
Ataru Sato View all 2 abstracts at Goldschmidt2020 View abstracts at 3 conferences in series
Yvonne Roebbert View all 2 abstracts at Goldschmidt2020 View abstracts at 8 conferences in series
Tonya Vitova View all 3 abstracts at Goldschmidt2020 View abstracts at 4 conferences in series
Marinella Mazzanti View all 2 abstracts at Goldschmidt2020 View abstracts at 3 conferences in series
Minori Abe View all 2 abstracts at Goldschmidt2020 View abstracts at 4 conferences in series
Stefan Weyer View all 6 abstracts at Goldschmidt2020 View abstracts at 21 conferences in series
Listed below are questions that have been submitted by the community that the author will try and cover in their presentation. To submit a question, ensure you are signed in to the website. Authors or session conveners approve questions before they are displayed here.
Submitted by Pieter Bots on Monday 15th June 16:02
Thank you for your presentations, this was really interesting! I was wondering if it is known if and/or how DPAEA impacts on the mechanisms of microbial redox reactions and the respective fractionation; does the DPAEA impact on the U(VI) -> U(V) -> U(IV) reaction mechanisms and fractionation, and could DPAEA impact on the isotopic exchange between U(V) and U(IV)? I am also curious if the fractionation and the variations in the fractions could help distinguishing between e.g. direct enzymatic reduction, reduction coupled to oxidation of enzymatically reduced Fe/S, and/or disproportionation? Thanks again (P. Bots)
Thank you, Pieter. yes, we think that the U(IV) product may include DPAEA, which would mean that it may sequester the U in such a way as to preclude isotopic exchange. But, we don't know this for a fact. I think the second part of your question refers to the use of DPAEA in other systems. This could be an interesting idea for abiotic systems. We haven't done that at all as of yet. Thank you.
Thank you for your presentations, this was really interesting! I was wondering if it is known if and/or how DPAEA impacts on the mechanisms of microbial redox reactions and the respective fractionation; does the DPAEA impact on the U(VI) -> U(V) -> U(IV) reaction mechanisms and fractionation, and could DPAEA impact on the isotopic exchange between U(V) and U(IV)? I am also curious if the fractionation and the variations in the fractions could help distinguishing between e.g. direct enzymatic reduction, reduction coupled to oxidation of enzymatically reduced Fe/S, and/or disproportionation? Thanks again (P. Bots)
Thank you, Pieter. yes, we think that the U(IV) product may include DPAEA, which would mean that it may sequester the U in such a way as to preclude isotopic exchange. But, we don't know this for a fact. I think the second part of your question refers to the use of DPAEA in other systems. This could be an interesting idea for abiotic systems. We haven't done that at all as of yet. Thank you.
Submitted by Ruth Tinnacher on Saturday 20th June 20:25
Submitted by Pieter Bots on Monday, June 15 08:02 (America/Los_Angeles) Thank you for your presentations, this was really interesting! I was wondering if it is known if and/or how DPAEA impacts on the mechanisms of microbial redox reactions and the respective fractionation; does the DPAEA impact on the U(VI) -> U(V) -> U(IV) reaction mechanisms and fractionation, and could DPAEA impact on the isotopic exchange between U(V) and U(IV)? I am also curious if the fractionation and the variations in the fractions could help distinguishing between e.g. direct enzymatic reduction, reduction coupled to oxidation of enzymatically reduced Fe/S, and/or disproportionation? Thanks again (P. Bots) From Ruth Tinnacher: Very interesting presentation. Thank you! Not being an isotope geochemist, I was wondering about the following. *) Would you expect that the kinetically limited U isotope exchange between U(V)-DPAEA and U(IV)-DPAEA is affected by the fact that U(V)-DPAEA stays in solution while U(IV)-DPAEA forms a solid? *) Can you make any guesses if we should see similar behavior for other U solution complexes, e.g. with carbonate ligands?
Submitted by Pieter Bots on Monday, June 15 08:02 (America/Los_Angeles) Thank you for your presentations, this was really interesting! I was wondering if it is known if and/or how DPAEA impacts on the mechanisms of microbial redox reactions and the respective fractionation; does the DPAEA impact on the U(VI) -> U(V) -> U(IV) reaction mechanisms and fractionation, and could DPAEA impact on the isotopic exchange between U(V) and U(IV)? I am also curious if the fractionation and the variations in the fractions could help distinguishing between e.g. direct enzymatic reduction, reduction coupled to oxidation of enzymatically reduced Fe/S, and/or disproportionation? Thanks again (P. Bots) From Ruth Tinnacher: Very interesting presentation. Thank you! Not being an isotope geochemist, I was wondering about the following. *) Would you expect that the kinetically limited U isotope exchange between U(V)-DPAEA and U(IV)-DPAEA is affected by the fact that U(V)-DPAEA stays in solution while U(IV)-DPAEA forms a solid? *) Can you make any guesses if we should see similar behavior for other U solution complexes, e.g. with carbonate ligands?
Submitted by Ruth Tinnacher on Saturday 20th June 21:07
Very interesting talk. Thank you. Two questions from someone who is not an isotope geochemist: *) Would you expect that the kinetically limited U isotope exchange between U(V)-DPAEA and U(IV)-DPAEA is affected by the fact that U(V)-DPAEA stays in solution while U(IV)-DPAEA forms a solid? *) Can you make any guesses if we should see similar behavior for other U solution complexes, e.g. with carbonate ligands?
Thanks for your question. No, I don't think so because we have tested this with other U-ligand species that can adsorb and the same result is observed. For U-carbonate systems, the U(IV) species are likely to undergo isotope exchange much more readily. Hence, the enzymatic fractionation may be overprinted by the isotopic exchange.
Very interesting talk. Thank you. Two questions from someone who is not an isotope geochemist: *) Would you expect that the kinetically limited U isotope exchange between U(V)-DPAEA and U(IV)-DPAEA is affected by the fact that U(V)-DPAEA stays in solution while U(IV)-DPAEA forms a solid? *) Can you make any guesses if we should see similar behavior for other U solution complexes, e.g. with carbonate ligands?
Thanks for your question. No, I don't think so because we have tested this with other U-ligand species that can adsorb and the same result is observed. For U-carbonate systems, the U(IV) species are likely to undergo isotope exchange much more readily. Hence, the enzymatic fractionation may be overprinted by the isotopic exchange.
Submitted by Stephen Romaniello on Monday 22nd June 19:54
Hi Rizlan, great talk and a very nice experimental system! Extrapolating from this work, do you think the reason we typically see larger isotopic fractionation during biotic reduction is that something in that process is facilitating isotopic exchange between U(6) and U(4)?
Thanks Steve. Well, the product of biotic reduction is typically non-crystalline U(IV). The hypothesis is that this type of U(IV) species is readily available for isotopic exchange. But, this remains a hypothesis since it has not been probed yet. We are working on this and hope to be able to answer the question in the near future.
Hi Rizlan, great talk and a very nice experimental system! Extrapolating from this work, do you think the reason we typically see larger isotopic fractionation during biotic reduction is that something in that process is facilitating isotopic exchange between U(6) and U(4)?
Thanks Steve. Well, the product of biotic reduction is typically non-crystalline U(IV). The hypothesis is that this type of U(IV) species is readily available for isotopic exchange. But, this remains a hypothesis since it has not been probed yet. We are working on this and hope to be able to answer the question in the near future.
Submitted by Rizlan Bernier-Latmani on Monday 22nd June 22:42
Thanks Steve. Well, the product of biotic reduction is typically non-crystalline U(IV). The hypothesis is that this type of U(IV) species is readily available for isotopic exchange. But, this remains a hypothesis since it has not been probed yet. We are working on this and hope to be able to answer the question in the near future.
Thanks Steve. Well, the product of biotic reduction is typically non-crystalline U(IV). The hypothesis is that this type of U(IV) species is readily available for isotopic exchange. But, this remains a hypothesis since it has not been probed yet. We are working on this and hope to be able to answer the question in the near future.
Submitted by Rizlan Bernier-Latmani on Monday 22nd June 22:42
Thanks Steve. Well, the product of biotic reduction is typically non-crystalline U(IV). The hypothesis is that this type of U(IV) species is readily available for isotopic exchange. But, this remains a hypothesis since it has not been probed yet. We are working on this and hope to be able to answer the question in the near future.
Thanks Steve. Well, the product of biotic reduction is typically non-crystalline U(IV). The hypothesis is that this type of U(IV) species is readily available for isotopic exchange. But, this remains a hypothesis since it has not been probed yet. We are working on this and hope to be able to answer the question in the near future.
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