Publications associées à Coupled Biogeochemical Processes for the Reduction and Immobilization of Uranium

Atomic level insight into irradiation effects in nuclear fuel materials

Microstructural evolution during in-pile irradiation, radiation damage effects and fission products behavior in UO2 nuclear fuel are key issues in understanding and for the modeling of the performance as well as safety characteristics of nuclear fuels in t ...

EPFL2024

A Route to Stabilize Uranium(II) and Uranium(I) Synthons in Multimetallic Complexes

Rosario Scopelliti, Marinella Mazzanti, Ivica Zivkovic, Dieuwertje Katelijn Modder

Herein, we report the redox reactivity of a multimetallic uranium complex supported by triphenylsiloxide (−OSiPh3) ligands, where we show that low valent synthons can be stabilized via an unprecedented mechanism involving intramolecular ligand migration. T ...

Wiley-VCH Verlag GmbH2023

Implementing Multi-Electron Transfer Strategies in Uranium Chemistry

Dieuwertje Katelijn Modder

In the last decades, the activation of small molecules has attracted increasing attention for their use as cheap and abundant feedstock. Low-oxidation state uranium complexes have displayed high reactivity towards small molecules thanks to their unique pro ...

EPFL2023

Biostimulation as a sustainable solution for acid neutralization and uranium immobilization post acidic in-situ recovery

Pierre Rossi, Rizlan Bernier-Latmani, Thomas Coral

Major uranium (U) deposits worldwide are exploited by acid leaching, known as 'in-situ recovery' (ISR). ISR involves the injection of an acid fluid into ore-bearing aquifers and the pumping of the resulting metal-containing solution through cation exchange ...

2022

Multi-electron Transfer by U(II) and Masked U(II) Complexes

Marinella Mazzanti

Complexes of uranium in low oxidation state have shown the ability to activate non-reactive small molecules such as N-2. However, the multi-electron transfer required for such activation remains limited in uranium chemistry. Here, we review our recent rese ...

SWISS CHEMICAL SOC2022

Design, synthesis, reactivity, and magnetic properties of uranium based oxide and nitride complexes

Luciano Barluzzi

The activation of small molecules is a paramount challenge in modern chemistry. The use of cheap and abundant molecules such as N2, H2, CO2, or CO as energy supplies or as precursors for fine chemicals production is highly desirable. In particular, the onl ...

EPFL2021

Systematic investigations of uranium carbide composites oxidation from micro- to nano-scale: Application to waste disposal

Nhât-Tân Vuong

The production of radioisotope beams at the ISOLDE (Isotope Separator OnLine DEvice) facility at CERN is achieved by irradiating target materials (e.g. uranium carbides and metal foils) with protons. The materials are usually operated at temperatures above ...

EPFL2021

Insights into the microbial reduction of pentavalent and hexavalent uranium species by Shewanella oneidensis MR-1

Margaux Camille Andréa Molinas

Decades of uranium-related activities such as ore mining, nuclear power generation, weapon manufacture, storage of nuclear wastes, have contributed to the release of U in the environment. U occurrence is concerning, since in surface environments, U is typi ...

EPFL2021

Nanoscale mechanism of UO2 formation through uranium reduction by magnetite

Thomas La Grange, Rizlan Bernier-Latmani, Barbora Bártová, Zezhen Pan

Uranium (U) is a ubiquitous element in the Earth's crust at similar to 2 ppm. In anoxic environments, soluble hexavalent uranium (U(VI)) is reduced and immobilized. The underlying reduction mechanism is unknown but likely of critical importance to explain ...

Nature Research2020

Role of Iron Sulfide Phases in the Stability of Noncrystalline Tetravalent Uranium in Sediments

Rizlan Bernier-Latmani, Luca Loreggian

Uranium (U) in situ bioremediation has been investigated as a cost-effective strategy to tackle U contamination in the subsurface. While uraninite was believed to be the only product of bioreduction, numerous studies have revealed that noncrystalline U(IV) ...

AMER CHEMICAL SOC2020

Synthesis, reactivity, and environmental relevance of uranyl(V) complexes

Radmila Faizova

Knowledge of fundamental chemical properties of all environmentally relevant uranium species is essential to understand environmental uranium mobility and develop novel remediation strate-gies. A myriad of uranium(VI) and uranium(IV) compounds has been stu ...

EPFL2020

Development and verification of pin-by-pin homogenized simplified transport solver Tortin for PWR core analysis

Andreas Pautz, Petra Mala

Currently, the pin-by-pin homogenized solvers are a very active research field as they can, unlike the nodal codes, directly predict the local power, while requiring significantly less computational resources than the heterogeneous transport codes. This pa ...

2020

Small molecule activation by multimetallic uranium complexes supported by siloxide ligands

Marinella Mazzanti, Marta Falcone, Luciano Barluzzi

The synthesis and reactivity of uranium compounds supported by the tris-tert-butoxysiloxide ligand is surveyed. The multiple binding modes of the tert-butoxysiloxide ligand have proven very well suited to stabilize highly reactive homo- and heteropolymetal ...

Royal Society of Chemistry2019

Effect of Aging on the Stability of Microbially Reduced Uranium in Natural Sediment

Rizlan Bernier-Latmani, Barbora Bártová, Agnès Novotny, Yuheng Wang, Sophie Louise Bretagne, Luca Loreggian

Reductive immobilization of uranium has been explored as a remediation strategy for the U-contaminated subsurface. Via the in situ biostimulation of microbial processes, hexavalent U is reduced to less soluble tetravalent species, which are immobilized wit ...

2019

Non-crystalline tetravalent uranium species in the subsurface: formation and stability

Luca Loreggian

Uranium (U) contamination of ground and surface waters poses an acute hazard on the ecosystem and human health. Since the discovery of microbial U(VI) reduction, U bioremediation has been explored as a promising and cost-effective method compared to tradit ...

EPFL2019

Facile N-functionalization and strong magnetic communication in a diuranium(v) bis-nitride complex

Marinella Mazzanti, Ivica Zivkovic, Farzaneh Fadaei Tirani, Lucile Sylvie Danielle Chatelain, Luciano Barluzzi

Uranium nitride complexes are of high interest because of their ability to effect dinitrogen reduction and functionalization and to promote magnetic communication, but studies of their properties and reactivity remain rare. Here we have prepared in 73% yie ...

2019

Structural Snapshots of Cluster Growth from {U6 } to {U38 } During the Hydrolysis of UCl4

Marinella Mazzanti, Farzaneh Fadaei Tirani, Lucile Sylvie Danielle Chatelain, Radmila Faizova

Herein we report the assembly of large uranium(IV) clusters with novel nuclearities and/or shapes from the controlled hydrolysis of UCl4 in organic solution and in the presence of the benzoate ligands. {U6}, {U13}, {U16}, {U24}, {U38} oxo and oxo/hydroxo c ...

Wiley-VCH Verlag GmbH2019

Small Molecule Activation by Multimetallic Uranium Complexes

Marta Falcone

The development of new processes for the selective and sustainable transformation of abundant small molecules constitutes one of the major research areas in inorganic and organometallic chemistry. These molecules as CO2, CO, N2 and H2 are abundant reservoi ...

EPFL2019

Four-electron Reduction and Functionalization of N₂ by a Uranium(III) Bridging Nitride

Marinella Mazzanti, Marta Falcone

N2 is a cheap and widely available but very unreactive molecule. Notably, the only industrial process for the conversion of dinitrogen is the Haber-Bosch process to form ammonia, but under very harsh conditions (high temperature and pressure). Here, we rev ...

2018

Microbial communities associated with uranium in-situ recovery mining process are related to acid mine drainage assemblages

Luiz Felippe De Alencastro, Pierre Rossi, Rizlan Bernier-Latmani, Thomas Coral

A large fraction (47%) of the world's uranium is mined by a technique called “In Situ Recovery” (ISR). This mining technique involves the injection of a leaching fluid (acidic or alkaline) into a uranium-bearing aquifer and the pumping of the resulting sol ...

2018