Concept

Kinetic fractionation

Publications associées (39)

The isotopic signature of U(V) during bacterial reduction

Marinella Mazzanti, Rizlan Bernier-Latmani, Margaux Camille Andréa Molinas, Radmila Faizova, Ashley Richards Brown

The two-step electron transfer during bacterial reduction of UVI to UIV is typically accompanied by mass-independent fractionation of the 238U and 235U isotopes, whereby the heavy isotope accumulates in the reduced product. However, the role of the UV inte ...

2024

Mercury Isotope Fractionation during Dark Abiotic Reduction of Hg(II) by Dissolved, Surface-Bound, and Structural Fe(II)

Lorenz Schwab

Stable mercury (Hg) isotope ratios are an emerging tracer for biogeochemical transformations in environmental systems, but their application requires knowledge of isotopic enrichment factors for individual processes. We investigated Hg isotope fractionatio ...

Washington2023

Hydrogen Peroxide Formation during Ozonation of Olefins and Phenol: Mechanistic Insights from Oxygen Isotope Signatures

Urs von Gunten, Joanna Maria Houska

Mitigation of undesired byproducts from ozonation of dissolved organic matter (DOM) such as aldehydes and ketones is currently hampered by limited knowledge of their precursors and formation pathways. Here, the stable oxygen isotope composition of H2O2 for ...

AMER CHEMICAL SOC2023

Snow-Atmosphere Humidity Exchange at the Ice Sheet Surface Alters Annual Mean Climate Signals in Ice Core Records

Sonja Wahl

Surface processes alter the water stable isotope signal of the surface snow after deposition. However, it remains an open question to which extent surface post-depositional processes should be considered when inferring past climate information from ice cor ...

Washington2023

High-useful yield and new autoionizing state of resonantly ionized tungsten

Reto Georg Trappitsch

In order to measure tungsten isotopic composition in presolar stardust grains that contain a limited number of atoms, we developed a new three-photon three-color resonance ionization scheme using titanium:sapphire lasers and the Laser Ionization of Neutral ...

ROYAL SOC CHEMISTRY2022

Surface snow isotopic composition: Post-depositional processes in an alpine snowpack

Michael Lehning, Luca Bianchi, Yoann Nicolas Sadowski

Stable water isotopes are natural tracers allowing to reconstruct the history of a water parcel. They are used as climate proxies and to better understand the hydrological cycle. The snow isotopic composition is directly influenced by temperatures and atmo ...

2022

Ab initio and steady-state models for uranium isotope fractionation in multi-step biotic and abiotic reduction

Rizlan Bernier-Latmani

Hexavalent uranium (U(VI)) is reduced to tetravalent uranium (U(IV)) by microorganisms (e.g., Geobacter or Shewanella spp.) as well as by abiotic reductants such as sulfide or Fe(II) species. During reduction, the heavy isotope (238U) is typically enriched ...

2021

Uranium Isotope Fractionation during the Anoxic Mobilization of Noncrystalline U(IV) by Ligand Complexation

Rizlan Bernier-Latmani, Ashley Richards Brown

Uranium (U) isotopes are suggested as a tool to trace U reduction. However, noncrystalline U(IV), formed predominantly in near-surface environments, may be complexed and remobilized using ligands under anoxic conditions. This may cause additional U isotope ...

2021

Toward waste valorization by converting bioethanol production residues into nanoparticles and nanocomposite films

Xun Liao, Muhammad Farooq

A "waste-valorization" approach was developed to transform recalcitrant hydrolysis lignin (HL) from secondgeneration bioethanol production into multifunctional bio-based products. The hydrolysis lignin (HL) was extracted with aqueous acetone, yielding two ...

ELSEVIER2021

Technical note: Evaluation of a low-cost evaporation protection method for portable water samplers

Jana Freiin von Freyberg

Automated field sampling of streamwater or precipitation for subsequent analysis of stable water isotopes (H-2 and O-18) is often conducted with off-the-shelf automated samplers. However, when water samples are stored in the field for days and weeks in ope ...

COPERNICUS GESELLSCHAFT MBH2020

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